sildenafil-citrate and HIV-Infections

Methamphetamine (meth) use has been shown in the literature to be associated with high-risk sexual behavior for both homosexual (MSM) and heterosexual samples for over a decade. The use of Viagra has also been shown to be associated with high-risk sexual behavior. The purpose of this review is to update the record on Viagra and on the combination of Viagra and meth use.. There is now strong evidence that the use of Viagra is associated with HIV seroconversion in MSM. The combination of taking both meth and Viagra is strongly associated with much higher sexually transmitted disease and HIV rates. There is some evidence that Viagra is associated with insertive and meth is associated with receptive anal intercourse by men.. The evidence is strong to support the relationship between Viagra use and HIV seroconversion now that more sophisticated analyses have been done. The meth-Viagra recreational drug combination is of very high risk. More research is needed to generate longitudinal and event-level data that are necessary to answer fine-grained questions about drug combinations and the relationship with sexual behavior.

Topics: HIV Infections; Homosexuality, Male; Humans; Male; Methamphetamine; Piperazines; Purines; Risk-Taking; Sexual Behavior; Sexually Transmitted Diseases; Sildenafil Citrate; Sulfones

Etravirine (ETR) belongs to the family of non-nucleoside analogue reverse transcriptase inhibitors (NNRTIs), with antiviral activity in patients with resistance to first-generation NNRTIs. The drug interactions caused by ETR are due to its dual effect on the CYP450 system. ETR acts as an inducer of CYP3A4 and inhibitor of CYP2C9 and CYP2C19. This drug shows few clinically significant drug interactions, the most important of which involve the unboosted protease inhibitors, the NNRTIs efavirenz and nevirapine, full-dose ritonavir and tipranavir/ritonavir. Interaction with fosamprenavir/ritonavir is not clinically significant, although their plasma levels vary slightly when used in combination with ETR. ETR shows no interactions with darunavir/ritonavir.

Topics: Analgesics; Anesthetics; Anti-HIV Agents; Anti-Infective Agents; Anticonvulsants; Antiretroviral Therapy, Highly Active; Aryl Hydrocarbon Hydroxylases; Biotransformation; Contraceptives, Oral, Hormonal; Contraindications; Cytochrome P-450 CYP2C19; Cytochrome P-450 CYP2C9; Cytochrome P-450 CYP3A; Drug Interactions; Drug Therapy, Combination; Enzyme Induction; HIV Infections; HIV Protease Inhibitors; HIV Reverse Transcriptase; HIV-1; Humans; Microsomes, Liver; Nitriles; Piperazines; Purines; Pyridazines; Pyrimidines; Reverse Transcriptase Inhibitors; Sildenafil Citrate; Sulfones

Modern health care has greatly increased longevity for patients with congenital hemolytic anemias (such as sickle cell disease and thalassemia) and human immunodeficiency virus (HIV) infection. It is estimated that 10% of patients with hemoglobinopathies and 0.5% of patients with HIV infection develop moderate to severe pulmonary hypertension. Pulmonary hypertension is a relentlessly progressive disease leading to right heart failure and death. Worldwide, there are an estimated 30 million patients with sickle cell disease or thalassemia and 40 million patients with HIV disease. Considering the prevalence of pulmonary vascular disease in these populations, sickle cell disease and HIV disease may be the most common causes of pulmonary hypertension worldwide. In this review, the available data on epidemiology, hemodynamics, mechanisms, and therapeutic strategies for these diseases are summarized. Because therapy is likely to reduce morbidity and prolong survival, efforts to screen, diagnose, and treat these patients represent a global health opportunity.

Topics: Anemia, Hemolytic, Congenital; Anemia, Sickle Cell; Antiretroviral Therapy, Highly Active; Blood Transfusion; Echocardiography, Doppler, Color; Heart Failure; HIV Infections; Humans; Hypertension, Pulmonary; Hypertrophy, Right Ventricular; Male; Piperazines; Purines; Sildenafil Citrate; Sulfones; Vasodilator Agents

To determine the rates of sildenafil (Viagra) use among different populations, primarily among men who have sex with men, and to measure the association of sildenafil use with increased sexual risk behavior and sexually transmitted diseases (STDs), including human immunodeficiency virus (HIV) infection.. The National Center for Biotechnology Information PubMed was searched using a variety of terms for relevant publications from January 1999 to July 2004. In addition, all scientific abstracts from national and international conferences on STDs from January 1999 to July 2004 were searched. Relevant journal articles and scientific abstracts presenting original data and meeting given criteria were included.. Fourteen studies met the inclusion criteria. Seven of the 11 studies in men who have sex with men showed sildenafil use rates >10% (range 3%-32%). Increased odds of unprotected anal sex with a partner of unknown or serodiscordant HIV status ranged from 2.0 to 5.7 times (mean = 3.9) for sildenafil users versus nonusers. The risk of sildenafil use and STD diagnosis among HIV-positive men who have sex with men was 1.92 (P = 0.05), and the odds of sildenafil use among those newly HIV infected was 2.5 (95% CI 1.1-4.1).. Most studies reported frequent sildenafil use in men who have sex with men, and several showed independent associations between use of the drug and sexual risk behavior, as well as an increased risk for STDs, including incident HIV infection. Although future research among more varied participants is needed, these results warrant a multi-faceted response to reduce the misuse of sildenafil and its consequences, particularly among men who have sex with men.

Topics: Comorbidity; Heterosexuality; HIV Infections; Homosexuality; Humans; Male; Piperazines; Purines; Risk-Taking; Sexually Transmitted Diseases; Sildenafil Citrate; Substance-Related Disorders; Sulfones

Topics: Antihypertensive Agents; Electrocardiography; Epoprostenol; HIV Infections; Humans; Hypertension, Pulmonary; Piperazines; Purines; Sildenafil Citrate; Sulfones; Vasodilator Agents

Since the sexual revolution of the 1960s, medical complications of sexual activity and sexual side effects related to use of medications have become a significant part of healthcare practice. Specifically, there has been an expanding interest in the treatment of headaches and their relationship to sexual function. Most sexual side effects associated with headache treatment are benign and can be managed with reassurance or changes in medication regimens. However, sudden headache should always be investigated carefully to rule out a dangerous intracranial event.

Topics: Antidepressive Agents; Antihypertensive Agents; Coitus; Female; Headache; HIV Infections; Humans; Male; Phosphodiesterase Inhibitors; Piperazines; Purines; Sexual Dysfunction, Physiological; Sildenafil Citrate; Sulfones

The objective of this study was to investigate if sildenafil influences the pharmacokinetics of nelfinavir. Five HIV-infected patients on steady-state nelfinavir-containing therapy were subject to pharmacokinetic sampling for nelfinavir concentration twice: without sildenafil and with sildenafil 25 mg as a single dose. There were no differences in the AUC, T(max), or C(max) of nelfinavir. In a similar design, two patients on indinavir and two patients on ritonavir combined with saquinavir were studied. In accordance with the literature, neither of these two treatments was affected. It is concluded that nelfinavir pharmacokinetics were unaffected by concomitant intake of a single dose of sildenafil.

Topics: Adult; Area Under Curve; Chromatography, High Pressure Liquid; Drug Interactions; Drug Therapy, Combination; Erectile Dysfunction; Half-Life; HIV Infections; HIV Protease Inhibitors; Humans; Indinavir; Male; Middle Aged; Nelfinavir; Piperazines; Purines; Ritonavir; Saquinavir; Sildenafil Citrate; Sulfones; Vasodilator Agents

Sexualized drug use (SDU) to enhance and extend sexual relations may involve risks of substances abuse (intoxication, interactions and overdose) and higher exposure to HIV and other sexually transmitted infections. There are inconsistencies in the methodology and findings of previous research on SDU in Latin America (LA), and more studies are required. The purpose of this research was to characterize SDU in gay men and other men who have sex with men from 18 LA countries, and describe the aspects by comparing people who practice and do not practice SDU, at the general and country levels.. Cross-sectional study based on the data collected by LAMIS-2018. Dependent variable was SDU (last 12 months), and the independent variables were: drug use (in any context/in sexual context), sociodemographic, socioepidemiological, and psychosocial aspects. A descriptive analysis was carried out, comparing those who practiced and did not practice SDU.. LAMIS-2018 included 64,655 participants, averaging 30 years of age. 13.6% declared having practiced SDU (6.6% with multiple partners). In the last sexual encounter the most commonly used drugs were cannabis (9.3%), poppers (6%), and Viagra (5.4%), and in the last encounter with multiple partners, poppers (19.7%), cannabis (17%), and Viagra (13.2%). HIV diagnosis was reported by 27% of people practicing SDU, vs. 14.3% in the other group. Severe anxiety-depression symptoms were more common among people practicing SDU (9.2% vs. 7%), as were the episodes of homophobic intimidation (52.6% vs. 48.2%), insults (34.4% vs. 28.6%), and aggression (4.1% vs. 3.0%).. SDU was reported by a high percentage of people, with a predominance of the use of drugs related to sexual practice, and others for recreational use. Aspects described as the higher proportion of self-reported HIV diagnosis and severe symptoms of anxiety-depression among those who practiced SDU, show that is necessary to implement preventive strategies to reduce the harmful impacts that can sometimes result from this practice, including harm reduction policies, promote access to mental health services and support in situations of homophobia and stigma.

Topics: Cross-Sectional Studies; HIV Infections; Homosexuality, Male; Humans; Latin America; Male; Sexual and Gender Minorities; Sexual Behavior; Sildenafil Citrate; Substance-Related Disorders

This original study compares the prevalences of drug use for any purpose and for sexualized drug use (SDU) among MSM. It also describes relevant characteristics of first SDU, analyzes to what extent SDU has been the first experience (the gateway) with different drugs by age and explores the correlates of SDU. Study participants included 2,919 HIV-negative MSM attending four HIV/STI diagnosis services in Madrid and Barcelona. They answered an online, self-administered questionnaire. Poisson regression models with robust variance were used. About 81.4% had ever used any drug, and 71.9% had done so in the last-12-months, while 56% had ever engaged in SDU, and 50% had done so in the last-12-months. Participants under 25 years old had the lowest prevalences of SDU, and the 25-39 age group the highest, except for Viagra, which was higher among those over age 40. The most frequently used drugs for first SDU were poppers (53.6%), cannabis (19.6%) and Viagra (12.2%). These drugs were also the most ever consumed for SDU. Among sexualized users, methamphetamine (78.3%) and Mephedrone (75.4%) were used always/most of the times for sex in the last-12-months. Around 72.2% of Mephedrone sexualized users and 69.6% of Methamphetamine vs 23.1% of ecstasy users' first consumption of these drugs involved use for sex. These drugs were provided to them free where they have sex for 66.8, 79.1, and 31.9%, respectively. On that occasion, 8.1% of Mephedrone, 6.8% of Methamphetamine and 18.4% of ecstasy users had sex only with steady partner; with 50.2, 56.2, and 26.2% respectively using a condom with any partner. SDU in the first use was associated with similar variables for recreational and chemsex drugs. The highest prevalence ratios were for having ever been penetrated by >20 men and having ever injected drugs. It can be concluded that the prevalence of SDU was more than half of the prevalence for any purpose. Thus SDU was the gateway to use for many drugs in an important proportion of users, who frequently consumed drugs that were free and had condomless anal sex with occasional and multiple partners. These circumstances were much more common for chemsex than for recreational drugs.

Topics: Adult; Child, Preschool; HIV Infections; Homosexuality, Male; Humans; Male; Methamphetamine; N-Methyl-3,4-methylenedioxyamphetamine; Sexual and Gender Minorities; Sexually Transmitted Diseases; Sildenafil Citrate; Substance-Related Disorders

Pulmonary hypertension associated with human immunodeficiency virus infection is an extremely rare disease in pediatrics; it requires a high clinical suspicion to reach a diagnosis. Its appearance poses an unfavorable prognostic, but early diagnosis and specific treatment can improve outcomes. We report the clinical case of a fifteen-year-old patient diagnosed with human immunodeficiency virus infection of vertical transmission, without antiretroviral treatment, with cough and progressive exertional dyspnea, associated with signs of right heart failure in which severe pulmonary hypertension was diagnosed. After discarding other causes, it was assumed pulmonary hypertension associated with human immunodeficiency virus infection. Treatment was performed with sildenafil with good response.. La hipertensión pulmonar asociada a la infección por virus de inmunodeficiencia humana es una enfermedad sumamente infrecuente en pediatría, por lo que requiere alta sospecha clínica para llegar a su diagnóstico. Su aparición es de pronóstico desfavorable, pero el diagnóstico precoz y el tratamiento específico pueden mejorar su evolución. Se presenta el caso clínico de un paciente de 15 años con diagnóstico de infección por virus de inmunodeficiencia humana de transmisión vertical, sin tratamiento antirretroviral, con tos y disnea de esfuerzo progresiva asociadas a signos de falla cardíaca derecha en el cual se diagnosticó hipertensión pulmonar grave. Luego de descartarse otras causas, se asumió la hipertensión pulmonar asociada a la infección por virus de inmunodeficiencia humana. Se realizó el tratamiento con sildenafil y presentó buena respuesta.

Topics: Adolescent; Heart Failure; HIV Infections; Humans; Hypertension, Pulmonary; Infectious Disease Transmission, Vertical; Male; Severity of Illness Index; Sildenafil Citrate; Treatment Outcome; Vasodilator Agents

Erythema multiforme is mainly caused by drug allergy and infections. This is the case of a HIV-positive, 49-year-old male, recently cured for syphilis, that presented erythema multiforme minor, five days after taking sildenafil. He had a fast recovery, only with the use of antihistamines. Cell-mediated allergy to sildenafil was confirmed six months later, with the use of patch-tests.

Topics: Drug Eruptions; Erythema Multiforme; HIV Infections; Humans; Male; Middle Aged; Patch Tests; Phosphodiesterase 5 Inhibitors; Predictive Value of Tests; Remission Induction; Sildenafil Citrate; Treatment Outcome

Topics: Anti-Bacterial Agents; Clarithromycin; Death, Sudden, Cardiac; Dideoxynucleosides; Drug Combinations; Drug Interactions; Electrocardiography; Fatal Outcome; HIV Infections; Humans; Lamivudine; Lopinavir; Male; Middle Aged; Piperazines; Purines; Ritonavir; Sexual Behavior; Sildenafil Citrate; Sulfonamides; Vasodilator Agents

Pulmonary arterial hypertension (PAH) is one of the long-term complications of HIV infection. The incidence of HIV-PAH is estimated at 0.5% of HIV-infected individuals. The mechanism by which infection leads to full-blown PAH is unknown. We describe a 44-year-old female patient with HIV infection diagnosed in 2004. Pulmonary hypertension was diagnosed in 2006. Seven months after the first cardiovascular clinical signs had started, the patient was referred to hospital because she was in New York Heart Association functional class IV. She commenced treatment with sildenafil. After increasing the sildenafil dose to ensure therapeutic drug levels over 24 h, the PAH and physical performance of the patient improved significantly. Our experience confirms long-term benefits of sildenafil monotherapy in PAH-HIV adult patients with improvements in symptoms and echocardiographic findings.

Topics: Adult; Female; HIV Infections; Humans; Hypertension, Pulmonary; Piperazines; Purines; Sildenafil Citrate; Sulfonamides; Vasodilator Agents

To understand the illegal sidenafil use among middle-aged and elderly male clients of female sex workers (FSWs) in central region of Guangxi as well as on related risk factors. Initial evaluation regarding the effect of illegal sidenafil use on HIV infection among the middle-aged and elderly men was also conducted.. A survey was conducted among the over 50-year-olds male clients of low-grade prostitutions in central areas of Guangxi. Information on demographics, related behavior, and illegal sidenafil use was collected. 5 ml blood sample were taken to test antibodies of HIV and syphilis. PASW Statistics 18.0 was used for data analysis.. 2 056 questionnaires were completed. 23.1% of the participants said they had ever used illegal sidenafil. The risk of sildenafil use was low among the male clients who were not over 60 years old (OR = 0.586, 95% CI:0.459-0.749). The risks of sildenafil use among the male clients with frequencies(in the past 30 days) of having commercial sex behavior were:only once (OR = 0.184, 95%CI:0.090- 0.378), twice (OR = 0.187, 95%CI:0.089-0.378) or three times (OR = 0.181, 95%CI: 0.085-0.384) lower than those with more than five times. Being single (OR = 0.608, 95% CI: 0.396-0.933), married/cohabiting (OR = 0.533, 95% CI:0.391-0.727), having unstable partners (OR = 0.558, 95%CI:0.393-0.792) seemed to be protective on those who used sildenafil, among the study population. Factors as 'never use the condom (OR = 1.642, 95%CI:1.125-2.397) or 'seldom use as condom (OR = 1.840, 95%CI:1.278-2.648) when having commercial sex, were under high risk among the sildenafil users. Forty-seven subjects were HIV positive, with the prevalence as 2.29% in this study population. Male clients of the FSWs who used sidenafil were under 60 years of age and with higher risk of HIV infection.. people who were ≥60 years old, divorced/widowed/ separated, with frequencies (in the past 30 days) of having commercial sex more than 5 times, never or occasionally using a condom when having commercial sex etc., appeared at high risk. Middle-aged and elderly male clients who used sildenafil or sildenafil-like drugs were under high risk of contracting HIV infection.

Topics: Age Distribution; Aged; China; Condoms; Female; HIV Infections; Humans; Male; Middle Aged; Piperazines; Prescription Drug Misuse; Prevalence; Purines; Risk Factors; Sex Work; Sex Workers; Sexual Partners; Sildenafil Citrate; Sulfonamides; Syphilis

The role men who have sex with men and women (MSMW) play in heterosexual HIV transmission is not well understood. We analyzed baseline data from Project MIX, a behavioral intervention study of substance-using men who have sex with men (MSM), and identified correlates of unprotected vaginal intercourse, anal intercourse, or both with women (UVAI). Approximately 10 % (n = 194) of the men reported vaginal sex, anal sex, or both with a woman; of these substance-using MSMW, 66 % (129) reported UVAI. Among substance-using MSMW, multivariate analyses found unemployment relative to full/part-time employment (OR = 2.28; 95 % CI 1.01, 5.17), having a primary female partner relative to no primary female partner (OR = 3.44; CI 1.4, 8.46), and higher levels of treatment optimism (OR = 1.73; 95 % CI 1.18, 2.54) increased odds of UVAI. Strong feelings of connection to a same-race gay community (OR = 0.71; 95 % CI 0.56, 0.91) and Viagra use (OR = 0.31; 95 % CI 0.10, 0.95) decreased odds of UVAI. This work suggests that although the proportion of substance-using MSM who also have sex with women is low, these men engage in unprotected sex with women, particularly with primary female partners. This work highlights the need for further research with the substance using MSMW population to inform HIV prevention interventions specifically for MSMW.

Topics: Condoms; Female; Heterosexuality; HIV Infections; Homosexuality, Male; Humans; Male; Piperazines; Purines; Risk Factors; Sexual Behavior; Sexual Partners; Sildenafil Citrate; Substance-Related Disorders; Sulfones; Unemployment; Unsafe Sex

Topics: Aged, 80 and over; AIDS Serodiagnosis; Erectile Dysfunction; Exanthema; HIV Infections; Humans; Male; Needlestick Injuries; Piperazines; Purines; Sexual Behavior; Sildenafil Citrate; Spain; Sulfones; Symptom Assessment; Syphilis Serodiagnosis; Syphilis, Cutaneous; Travel; Treponema pallidum; Truth Disclosure; Widowhood; Wound Infection

Topics: Anti-Retroviral Agents; Central Nervous System Stimulants; Combined Modality Therapy; Dietary Supplements; Drug Interactions; Drug Therapy, Combination; Emergency Service, Hospital; Food Contamination; HIV Infections; Humans; Male; Methamphetamine; Middle Aged; Piperazines; Plant Preparations; Priapism; Purines; San Francisco; Secondary Prevention; Sildenafil Citrate; Sulfones; Treatment Outcome; Vasodilator Agents

Pulmonary hypertension associated with pregnancy carries a poor prognosis. We describe successful maternal-foetal outcome for a 30-year-old woman who was found to have severe pulmonary hypertension, human immunodeficiency virus (HIV) and an atrial septal defect. Prior to delivery, she was managed with subcutaneous enoxaparine, sildenafil, nitric oxide, careful maintenance of a euvolemic status and antiretroviral therapy. She was planned for an elective Caesarean section to reduce the risk of maternal-foetal HIV transmission, but went into labour in the coronary care unit. During delivery, antibiotic prophylaxis was given, although there was insufficient time for intravenous zidovudine. Peripartum, the patient was continued on nitric oxide and subcutaneous enoxaparine. She was eventually weaned off the nitric oxide and recovered well.

Topics: Anti-HIV Agents; Anticoagulants; Enoxaparin; Female; Heart Septal Defects, Atrial; HIV Infections; Humans; Hypertension, Pulmonary; Nitric Oxide; Piperazines; Pregnancy; Pregnancy Complications, Cardiovascular; Pregnancy Complications, Infectious; Pregnancy Outcome; Purines; Sildenafil Citrate; Sulfones; Vasodilator Agents; Zidovudine

Sildenafil is increasingly used for the therapy of pulmonary arterial hypertension (PAH) in HIV infected patients. However, concerns exist about pharmacokinetic interactions between sildenafil and protease inhibitors (PI); in particular, ritonavir has been shown to increase sildenafil AUC and Cmax by several folds. The aim of our study was to determine the plasma levels of sildenafil and PI in two HIV patients with PAH treated with antiretroviral therapy including ritonavir-boosted PI. Our patients both experienced sildenafil Cmax above 500 ng/mL; however, they did not report any significant adverse reactions to sildenafil during the follow-up period. Therapeutic drug monitoring of sildenafil should be taken in consideration during treatment in order to avoid overdosage.

Topics: Adult; Drug Interactions; Female; HIV Infections; HIV Protease Inhibitors; Humans; Hypertension, Pulmonary; Male; Middle Aged; Piperazines; Purines; Ritonavir; Sildenafil Citrate; Sulfones; Vasodilator Agents

Recent studies show that Viagra and methamphetamine use are associated with unprotected anal intercourse among men who have sex with men (MSM). In Long Beach, California, we have reported on an association between Viagra use and the use of amphetamines during sex. The current research investigated the use of both Viagra and amphetamine in men in Long Beach, California. Data on 1,839 men recruited into HIV prevention and testing programs were collected using the Risk Behavior Assessment. A generalized logit model was constructed comparing ever having used both amphetamine and Viagra together and separately, as compared to never having used either (referent). Men who used both methamphetamine and Viagra showed a significantly higher prevalence of hepatitis B, syphilis, and HIV compared to those who used only one or neither drug. Of the 1,794 complete cases, 11.1% (199/1794) had used both amphetamine and Viagra. Of 20 potential risk and protective factors for use of amphetamine and Viagra, 12 were significant predictors: ever used gamma-hydroxybutyrate (GHB), ever used cocaine, ever used ecstasy, being infected with HIV, race=White compared to other, ever having hepatitis B, ever using crack, ever given money to have sex, living in a hotel, ever been in drug treatment, and ever using heroin. The protective factor was being heterosexual. Viagra use was associated with insertive, and methamphetamine was associated with receptive, anal intercourse. GHB use appears to play a more important role than previously thought.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Amphetamine-Related Disorders; Chi-Square Distribution; Hepatitis B; HIV Infections; Homosexuality, Male; Humans; Interviews as Topic; Male; Methamphetamine; Middle Aged; Phosphodiesterase 5 Inhibitors; Piperazines; Prevalence; Purines; Risk Factors; Risk-Taking; Sexual Behavior; Sexual Partners; Sildenafil Citrate; Sulfones; Syphilis

To examine residents' attitudes about prescribing medication for erectile dysfunction in ethically challenging scenarios.. In 2009, the authors surveyed internal medicine and family medicine residents at the University of California, San Diego, School of Medicine, asking them to indicate how likely they would be to prescribe sildenafil citrate to patients in 10 hypothetical scenarios. Eight scenarios had three nested variables: sexual identity, HIV status, and risk level. Two involved adulterous behavior; these were compared with two with monogamous behavior. The survey included four attitudinal questions about medical care and societal values.. Of 128 eligible residents, 81 (63%) responded. Respondents were more likely to prescribe sildenafil to hypothetical patients with low-risk behavior than to those with high-risk behavior (P < .001), more likely to prescribe sildenafil to patients who were HIV negative than to those who were HIV positive (P < .001), and more likely to prescribe sildenafil to monogamous patients than to patients in adulterous relationships (P < .001). Respondents who agreed that physicians are obliged to protect patients from their own risky behavior were likely to prescribe sildenafil in fewer scenarios than those who disagreed (P = .005).. Extratherapeutic factors influenced residents' decisions about prescribing medication for erectile dysfunction. Paternalistic attitude was the only attitudinal factor that affected likelihood of prescribing sildenafil. Residency programs should help trainees understand the balance between respecting patients' rights and protecting society, and between personal values and professional obligations, as well as how biases may affect patient care.

Topics: Adult; Attitude of Health Personnel; California; Cross-Sectional Studies; Drug Utilization; Erectile Dysfunction; Ethnicity; Family Practice; Female; HIV Infections; Humans; Internal Medicine; Internship and Residency; Male; Piperazines; Purines; Risk Assessment; Sildenafil Citrate; Sulfones; Surveys and Questionnaires

The frequency of HIV infection is increasing in men who have sex with men (MSM) aged 40 and older yet little is known about factors that influence their risky sexual behavior, such as sexual positioning. The goal of this study was to examine multi-level factors associated with unprotected receptive anal intercourse (URAI) and unprotected insertive anal intercourse (UIAI) in MSM aged 40 and older. A community-based sample of 802 self-identified MSM aged 40-94 years was recruited through targeted outreach from community venues (e.g., bars, social events) in South Florida and completed an anonymous pen-and-paper questionnaire. Logistic regression showed that younger age (i.e., aged 40-59; odds ratio [OR]=0.6; 95% confidence interval [CI]: 0.4, 0.9), HIV-positive status (OR=2.8; 95% CI: 1.9, 4.0), drug use (OR=2.6; 95% CI: 1.7, 3.7), a larger number of male sexual partners (OR=1.7; 95% CI: 1.3, 2.3), and lower scores on internalized homonegativity (OR=0.9; 95% CI: 1.0, 1.0) were associated with higher risk for URAI. Younger age (OR=0.4; 95% CI: 0.3, 0.6), HIV-positive status (OR=1.5; 95% CI: 1.0, 2.1), drug use (OR=1.6; 95% CI: 1.1, 22.3), Viagra use (OR=1.7; 95% CI: 1.2, 2.4), larger number of sexual partners (OR=2.1; 95% CI: 1.6, 2.9), and holding views more characterized by high optimism concerning the future (OR=1.1; 95% CI: 1.0, 1.1) were associated with higher risk for UIAI. These results provide useful information that may guide the development of tailored prevention interventions to reduce the growing rates of HIV among MSM aged 40 and older.

Topics: Adult; Age Factors; Aged; Aged, 80 and over; Florida; HIV Infections; HIV Seropositivity; Homosexuality, Male; Humans; Logistic Models; Male; Middle Aged; Piperazines; Purines; Risk Factors; Risk-Taking; Sexual Behavior; Sexual Partners; Sildenafil Citrate; Substance-Related Disorders; Sulfones; Surveys and Questionnaires; Vasodilator Agents

Use of illicit drugs and oral erectile dysfunction medications (OEM) have been associated with risk behavior among gay men.. To determine the effects of illicit drugs and OEM as risk factors for HIV seroconversion in a community-based cohort of HIV-negative homosexually active men in Sydney, Australia.. Drug use in the previous 6 months and at the most recent sexual encounter; Most recent occasions of unprotected and protected anal intercourse; HIV-positive diagnosis.. From June 2001 to June 2007, participants were followed up with 6-monthly detailed behavioral interviews and annual testing for HIV. Detailed information about sexual, drug-using and other behavior was collected.. Among 1,427 participants enrolled, 53 HIV seroconverters were identified by June 2007. At baseline, 62.7% reported using illicit drugs in the previous 6 months, including 10.7% who reported at least weekly use. Illicit drug use was associated with unprotected anal intercourse with casual partners (P < 0.001). Use of illicit drugs was associated with increased risk of HIV infection at a univariate level, and this risk increased with greater frequency of use. This was also true of the use of OEM. Use of each type of illicit drug was included in multivariate analysis, and after controlling for sexual risk behaviors, only use of OEM remained significantly predictive of HIV infection (Hazard ratios [HR] = 1.75, CI = 1.31-2.33, P < 0.001), although amyl nitrite was of borderline significance (HR = 1.26, CI = 0.98-1.62, P = 0.074).. The association between drug use and increased risk of HIV infection was strongest for drugs used specifically to enhance sexual pleasure, particularly OEM. The risk of infection was substantially increased when both OEM and methamphetamine were used. Within more "adventurous" gay community subcultures, the interconnectedness of sexual behavior and drug use may be key to understanding HIV risk and is an appropriate priority in HIV-prevention efforts in this population.

Topics: Adolescent; Adult; Aged; Amyl Nitrite; Australia; Cohort Studies; Confidence Intervals; HIV Infections; HIV Seropositivity; Homosexuality, Male; Humans; Illicit Drugs; Male; Middle Aged; Phosphodiesterase Inhibitors; Piperazines; Purines; Risk Factors; Risk-Taking; Sexual Behavior; Sildenafil Citrate; Sulfones; Surveys and Questionnaires; Vasodilator Agents; Young Adult

A sexual marathon is defined as prolonged sexual activity over hours and even days. This exploratory study examined the phenomenon of sexual marathons in a sample of 341 HIV-positive methamphetamine-using men who have sex with men (MSM). Eighty-four percent of the men reported engaging in marathon sex while high on methamphetamine. MSM who engaged in sexual marathons and those who did not were compared in terms of background characteristics, methamphetamine use variables, alcohol and illicit drug use, sexual risk behaviors, and psychosocial factors. Men who engaged in marathon sex used significantly more illicit drugs, were more likely to use sildenafil (Viagra) and amyl nitrates, and scored higher on a sexual compulsivity scale compared to men who did not engage in marathon sex. In multivariate analyses, use of sildenafil in the past two months was significantly correlated with participation in sexual marathons. Findings are discussed in terms of their implications for HIV/STI prevention and intervention.

Topics: Adult; Alcohol-Related Disorders; Central Nervous System Stimulants; HIV Infections; Homosexuality, Male; Humans; Logistic Models; Male; Methamphetamine; Multivariate Analysis; Neuropsychological Tests; Nitrates; Pentanols; Piperazines; Purines; Risk-Taking; Sexual Behavior; Sildenafil Citrate; Substance-Related Disorders; Sulfones; Vasodilator Agents

We examined how drugs, high-risk sexual behaviors, and socio-demographic variables are associated with recent HIV infection among men who have sex with men (MSM) in a case-control study. Interviewers collected risk factor data among 111 cases with recent HIV infection, and 333 HIV-negative controls from Chicago and Los Angeles. Compared with controls, cases had more unprotected anal intercourse (UAI) with both HIV-positive and HIV-negative partners. MSM with lower income or prior sexually transmitted infections (STI) were more likely to be recently HIV infected. Substances associated with UAI included amyl nitrate ("poppers"), methamphetamine, Viagra (or similar PDE-5 inhibitors), ketamine, and gamma hydroxybutyrate (GHB). Cases more frequently used Viagra, poppers, and methamphetamine during UAI compared with controls. In multivariate analysis, income, UAI with HIV-positive partners, Viagra, and poppers remained associated with recent HIV seroconversion. Better methods are needed to prevent HIV among MSM who engage in high-risk sex with concurrent drug use.

Topics: Adult; Case-Control Studies; Central Nervous System Stimulants; Chicago; HIV Infections; Homosexuality, Male; Humans; Los Angeles; Male; Methamphetamine; Middle Aged; Piperazines; Purines; Risk Factors; Risk-Taking; Sildenafil Citrate; Socioeconomic Factors; Substance-Related Disorders; Sulfones; Surveys and Questionnaires; Vasodilator Agents

We describe a 44-year-old male patient with human immunodeficiency virus (HIV) infection and pulmonary arterial hypertension who was treated with several protease inhibitors and with sildenafil. In order to guide treatment with sildenafil, the pharmacokinetics and dynamics of sildenafil were monitored at various time points. In comparison with healthy subjects, the maximal concentration in plasma (Cmax), area under the curve (AUC), and elimination half-life of sildenafil were approximately doubled in the patient. After increasing the sildenafil dose to ensure therapeutic drug levels over 24 hours, the pulmonary arterial hypertension and physical performance of the patient improved significantly. We conclude that the elimination of sildenafil is impaired in patients treated with protease inhibitors, but to a lesser extent than predicted from single-dose studies reported in the literature. Patients treated concomitantly with protease inhibitors and sildenafil need close monitoring of plasma levels, pharmacodynamics, and toxicity of sildenafil in order to be treated optimally.

Topics: Adult; Area Under Curve; Drug Interactions; Half-Life; HIV Infections; HIV Protease Inhibitors; Humans; Hypertension, Pulmonary; Male; Piperazines; Purines; Reference Values; Sildenafil Citrate; Sulfones; Vasodilator Agents

To determine the prevalence and factors of Viagra use in combination with crystal methamphetamine and its association with HIV risk behavior in a probability sample of men who have sex with men (MSM).. A cross-sectional, random-digit dial telephone survey of MSM in San Francisco conducted between June 2002 and January 2003.. Of the 1976 MSM, 13.5% used Viagra alone, 7.1% used methamphetamine without Viagra, 9.6% used Viagra with a mood-altering substance (excluding methamphetamine), and 5.1% used Viagra with methamphetamine. Of the MSM using Viagra with methamphetamine, 57% were HIV-infected and 24% of these men reported serodiscordant unprotected insertive intercourse. Viagra used with methamphetamine was independently associated with a higher risk of serodiscordant unprotected insertive intercourse, serodiscordant unprotected receptive intercourse, and a recent diagnosis of a sexually transmitted disease.. MSM who use Viagra with crystal methamphetamine have high prevalence rates of HIV and engage in HIV risk behaviors.

Topics: Adult; HIV Infections; Homosexuality, Male; Humans; Male; Methamphetamine; Middle Aged; Piperazines; Prevalence; Purines; Risk Factors; Risk-Taking; Sampling Studies; San Francisco; Sildenafil Citrate; Sulfones

Topics: Anti-Bacterial Agents; Drug Interactions; Drug Therapy, Combination; HIV Infections; Humans; Nitriles; Piperazines; Purines; Pyridazines; Pyrimidines; Reverse Transcriptase Inhibitors; Sildenafil Citrate; Sulfones

Human Immunodeficiency Virus (HIV)-related pulmonary hypertension is a relatively rare disease that can affect HIV sufferers. This is almost always associated with a poor outcome and death. An 18 month-old girl, probably the youngest on record, was diagnosed to have pulmonary hypertension (PHT) and retrospectively found to have HIV infection. Sildenafil was used to control her PHT and she remains alive even after 2 years.

Topics: Cardiomegaly; Enzyme-Linked Immunosorbent Assay; Female; HIV Infections; Humans; Hypertension, Pulmonary; Infant; Piperazines; Purines; Sildenafil Citrate; Sulfones; Treatment Outcome; Vasodilator Agents

The objective of the study was to examine correlates of sexual risk behavior among men who have sex with men (MSM) traveling for leisure.. MSM (N = 304) visiting popular tourist areas completed a brief survey assessing sexual behavior and substances used while on vacation, including the use of erectile dysfunction medications (e.g., Viagra).. Forty-seven percent of the respondents were sexually active during their vacation, with a mean of 1.33 unprotected anal sex acts during their brief stay (mean = 3.6 days). More than half of the sexually active men reported sex with a partner of unknown HIV status. Individuals reporting substance use or taking erectile dysfunction medications reported higher rates of sexual risk behaviors.. Many MSM travelers report behaviors that may put their health at risk, including substance use and unprotected sexual activity. Interventions designed to reduce risk behaviors among MSM tourists are needed.

Topics: Adult; Delaware; Florida; HIV Infections; Homosexuality, Male; Humans; Male; Piperazines; Purines; Risk-Taking; Sexual Behavior; Sildenafil Citrate; Substance-Related Disorders; Sulfones; Surveys and Questionnaires; Travel

Previous studies reported associations between sildenafil (Viagra; Pfizer, New York, NY) use and risk behaviors among men who have sex with men (MSM) in limited geographic areas or special populations. The purpose of the present study was to examine Viagra use among a broader MSM population.. The 2002 HIV Testing Survey data from MSM recruited at bars in 10 US states was used to examine Viagra use in the 12 months preceding the interview. Independent correlates of Viagra use were identified using logistic regression.. Eleven percent (131/1177) of MSM reported recent Viagra use. Users were older (adjusted odds ratios [aOR] = 2.4 to 6.2, 95% CI: 1.2 to 13.6); were more likely be infected with HIV (aOR = 2.0, CI: 1.0 to 3.9); reported more male sex partners (aOR = 2.4 to 2.7, CI: 1.2 to 5.4); were twice as likely to have unprotected anal intercourse with a nonprimary male partner (aOR = 2.1, CI: 1.2 to 3.5); and were 3 times more likely to report illicit drug usage (aOR = 3.1, CI: 1.9 to 5.2). Fifty-three percent (70/131) of Viagra users simultaneously took illicit drugs.. Among MSM from numerous US cities, Viagra use is common and is associated with several high-risk behaviors. These findings are consistent with previous reports and emphasize the need for additional prevention counseling for MSM that incorporates messages targeting Viagra usage and risk behavior.

Topics: Administration, Oral; Adolescent; Adult; HIV Infections; Homosexuality, Male; Humans; Illicit Drugs; Male; Piperazines; Population Surveillance; Purines; Risk-Taking; Sexual Behavior; Sildenafil Citrate; Sulfones; Surveys and Questionnaires; United States

Topics: Advertising; Drug Industry; HIV Infections; Humans; Piperazines; Purines; Sildenafil Citrate; Sulfones

The objective of this study was to examine sildenafil (Viagra) use and its relationship to sexual risk behavior for HIV and sexually transmitted diseases among men who have sex with men (MSM).. A population-based telephone sample of MSM in San Francisco was interviewed about sexual behavior, substance use, HIV and health status, and demographic characteristics.. Recent Viagra use was reported by 29% of the sample and was associated with HIV serostatus, greater numbers of male sexual partners, higher levels of unprotected anal sex, and higher levels of illicit recreational drug use. Viagra use was not associated with age, race, or socioeconomic status.. Viagra use appears to have become a stable fixture of the sexual culture of MSM, crossing age, race, and socioeconomic subgroups. Its use is associated with a general behavioral risk pattern for HIV/STD transmission.

Topics: Health Status; HIV Infections; Homosexuality, Male; Humans; Interviews as Topic; Male; Piperazines; Population Surveillance; Purines; Risk-Taking; Sildenafil Citrate; Substance-Related Disorders; Sulfones; United States; Unsafe Sex; Urban Population

The substantial frequency of drug resistance in persons recently infected with HIV implies exposure among HIV-uninfected individuals to HIV-infected persons with drug-resistant virus. Although there is an increasing emphasis on understanding high-risk behavior among HIV-infected patients, little work has focused on those with drug-resistant virus.. We examined antiretroviral-treated patients with drug resistance in the Study of the Consequences of the Protease Inhibitor Era, a clinic-based cohort of HIV-infected adults. Sexual behavior was ascertained by self-administered questionnaire. Genotypic antiretroviral resistance testing was performed on isolates from participants with a plasma HIV RNA level > or =100 copies/mL.. Among 279 participants on antiretroviral therapy, 168 (60%) had genotypic resistance to at least 1 drug. In those with drug resistance, 27% of men who have sex with men (MSM) and 11% of heterosexual men and women reported at least 1 episode of unprotected penile-anal or penile-vaginal intercourse in the previous 4 months; 17% of MSM and 6% of heterosexual participants reported unprotected intercourse with an HIV-uninfected or status unknown partner. In a multivariable model of predictors of unprotected anal or vaginal intercourse with an HIV-uninfected or status unknown partner, there was strong evidence for an effect of younger age, depression, and sildenafil use and moderate evidence for frequent alcohol use.. Among HIV-infected patients with drug-resistant viremia, there is a substantial prevalence of high-risk sex with HIV-uninfected partners. The presence of definable risk factors for unsafe sex suggests a role for targeted rather than broad intervention, particularly when resources are limited.

Topics: Adult; Age Factors; Aged; Alcoholism; Anti-HIV Agents; Depression; Drug Resistance, Viral; Female; HIV; HIV Infections; Humans; Male; Middle Aged; Multivariate Analysis; Needle Sharing; Piperazines; Plasma; Purines; Risk-Taking; RNA, Viral; Sildenafil Citrate; Sulfones; Surveys and Questionnaires; Unsafe Sex

The FDA published new information on drug interactions that patients taking Reyataz should know.

Topics: Adenine; Atazanavir Sulfate; Carbolines; Drug Information Services; Drug Interactions; Drug Therapy, Combination; HIV Infections; Humans; Imidazoles; Oligopeptides; Organophosphonates; Organophosphorus Compounds; Piperazines; Purines; Pyridines; Reverse Transcriptase Inhibitors; Sildenafil Citrate; Sulfones; Tadalafil; Tenofovir; Triazines; Vardenafil Dihydrochloride

There is too little good news about sexually transmitted diseases (STDs) and sexual risk-taking behavior in the United States, and that continues to worry public health officials and HIV researchers.

Topics: Herpes Genitalis; HIV Infections; Humans; Piperazines; Public Health; Purines; Sexually Transmitted Diseases; Sildenafil Citrate; Sulfones; United States

The study aims were to evaluate the prevalence and predictors of sexual risk behaviors and urethral sexually transmitted disease (STD) among males entering care for HIV infection and to examine if sildenafil prescriptions are associated with potentially transmitting sexual risk behavior (PTSRB). The research design included (1) self-administered questionnaire of symptoms of sexually transmitted infection (STI), number of recent sex partners, unprotected sexual risk behaviors, use of drugs/alcohol during sex, and HIV disclosure; (2) urine gonorrhea/chlamydia polymerase chain reaction (PCR); and (3) record review for sildenafil prescriptions. A PTSRB was defined as insertive anal, vaginal, or oral sex without a condom. Between March 2001 and March 2002, 413 entrants were surveyed. The prevalence of positive urine PCR among those with and without urethral symptoms was 16.7% and 2.4%, respectively. Fifty-one percent met criteria for PTSRB during the preceding month. Those reporting PTSRB were more likely to report multiple partners. In a multiple logistic regression model, the following were significant (p < 0.05) predictors of PTSRB: drug or alcohol use during sex; white race; only male partners, and sildenafil use. Drug use during sex was associated both with more sex partners and more sexual risk behaviors. Always disclosing HIV status was associated with fewer partners. There was a high prevalence of PTSRB among HIV-infected males entering care. Men who have sex with men (MSM), white race, drug/alcohol use during sex, and sildenafil use were independent risk factors. PTSRB was associated with having multiple partners. Physicians should discuss risk behaviors before prescribing sildenafil.

Topics: Adult; California; Chlamydia Infections; Gonorrhea; HIV Infections; Humans; Logistic Models; Male; Mass Screening; Middle Aged; Multivariate Analysis; Phosphodiesterase Inhibitors; Piperazines; Prevalence; Prospective Studies; Purines; Risk Factors; Risk-Taking; Sexual Behavior; Sexually Transmitted Diseases; Sildenafil Citrate; Sulfones; Urethral Diseases

Topics: Adult; Aged; Erectile Dysfunction; HIV Infections; Humans; Male; Middle Aged; Piperazines; Purines; Risk Factors; Sexual Behavior; Sildenafil Citrate; Sulfones

The authors conducted a community-based anonymous survey of 837 men who have sex with men (MSM) to gauge the extent of Viagra (sildenafil citrate) use, its association with high-risk sexual behavior, and its combination with other drugs. Participants' mean age was 35 years, 67% were white, and 66% had a college degree. The majority (76%) reported anal sex in the past 6 months, with 49% reporting always using condoms. Overall, 32% had ever used Viagra (CI: 29%-36%). Significant independent predictors of Viagra use were white race, older age, HIV positivity, illicit drug use, and having had unprotected anal sex with potentially serodiscordant partners. Over one third of Viagra users had combined Viagra with other drugs, 18% with amyl nitrate. Only a minority (44%) obtained Viagra under the care of a physician. For some MSM, Viagra appears to be an emerging contributing factor to unsafe sex, potentially increasing HIV transmission. HIV care and prevention providers should target Viagra users for enhanced education on safer sex and potentially harmful drug interactions.

Topics: Adult; Condoms; HIV Infections; Homosexuality, Male; Humans; Logistic Models; Male; Middle Aged; Nitrates; Pentanols; Piperazines; Population Surveillance; Prevalence; Purines; Risk Factors; Safe Sex; San Francisco; Sexual Behavior; Sildenafil Citrate; Sulfones; Surveys and Questionnaires

Topics: Drug Labeling; HIV Infections; Humans; Piperazines; Purines; San Francisco; Sexually Transmitted Diseases; Sildenafil Citrate; Sulfones

Topics: Adult; Antihypertensive Agents; Antiretroviral Therapy, Highly Active; Female; HIV; HIV Infections; Humans; Hypertension, Pulmonary; Iloprost; Piperazines; Purines; Reverse Transcriptase Inhibitors; Sildenafil Citrate; Sulfones; Time; Vasodilator Agents

Topics: Female; HIV Infections; Humans; Hypertension, Pulmonary; Middle Aged; Piperazines; Purines; Sildenafil Citrate; Sulfones

The potential role of sildenafil (Viagra) in the risk of HIV and sexually transmitted disease (STD) transmission was evaluated among gay or bisexual men seeking public STD services in San Francisco. Viagra users reported greater numbers of recent sex partners, higher levels of unprotected anal sex with an HIV-positive partner, and higher rates of prevalent STD than non-users. Moreover, mixing Viagra with illicit drugs was commonly reported. Further studies are needed to determine whether a causal role exists.

Topics: Adolescent; Adult; Aged; Bisexuality; Disease Transmission, Infectious; HIV Infections; Homosexuality, Male; Humans; Male; Middle Aged; Piperazines; Purines; Risk Factors; San Francisco; Sexually Transmitted Diseases; Sildenafil Citrate; Sulfones; Vasodilator Agents

Topics: Adult; Female; HIV Infections; Humans; Hypertension, Pulmonary; Male; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones

Topics: Cross-Sectional Studies; HIV Antibodies; HIV Infections; Homosexuality, Male; Humans; London; Male; Piperazines; Purines; Risk-Taking; Sexual Behavior; Sildenafil Citrate; Sulfones; Surveys and Questionnaires

Topics: Drug Interactions; HIV Infections; HIV Protease Inhibitors; Humans; Piperazines; Purines; Sildenafil Citrate; Sulfones

Topics: Drug Interactions; Drug Therapy, Combination; Erectile Dysfunction; HIV Infections; HIV Protease Inhibitors; HIV-1; Humans; Male; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones

Topics: Anti-HIV Agents; Drug Interactions; Erectile Dysfunction; HIV Infections; HIV-1; Humans; Male; Middle Aged; Myocardial Infarction; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones

Topics: Anti-HIV Agents; Drug Interactions; Drug Therapy, Combination; HIV Infections; Humans; Male; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones

The prevalence of erectile dysfunction in HIV-infected men is estimated to be 33%. Sildenafil citrate (Viagra; Pfizer Ltd, Sandwich, Kent, UK) is the first oral drug for this condition. Since sildenafil and the protease inhibitors are both metabolized by, and act as inhibitors of cytochrome P450 3A4, we evaluated the pharmacokinetics of the combination sildenafil plus indinavir in HIV-infected patients.. Six patients at steady state in treatment with indinavir participated in the study. On the first day blood samples for indinavir assay were drawn at times 0, 1, 2, 3, 4, 6 and 8 h after dosing. On the second study day patients received a single dose of 25 mg of sildenafil in addition to their routine morning medication. Blood samples were taken as described. Separated plasma was stored at -80 degrees C until analysis by high performance liquid chromatography. In a parallel study, the effect of indinavir, ritonavir, saquinavir and nelfinavir on the in vitro hepatic metabolism of sildenafil was assessed.. The geometric mean area under the concentration curve for 0-8 h (AUC0-8h) and maximum plasma concentration (Cmax) for indinavir were 19.69 microg/ml h (range, 9.19-31.99 microg/ml h) and 7.02 microg/ml (range, 2.33-16.17 microg/ml), respectively, on the first study day. In the presence of sildenafil, the mean AUC0-8h and Cmax of indinavir were 22.37 microg/ml h [range, 10.08-37.25 microg/ml h; 95% confidence interval (CI) for difference between means, -15 to 13.25) and 9.11 microg/ml (range, 3.41-22.78 microg/ml; 95% CI, -13 to 6.37), respectively. The geometric mean AUC0-8h and Cmax for sildenafil were 1631 ng/ml h (range, 643-2970 ng/ml h) and 384 ng/ml (range, 209-766 ng/ml) respectively. The AUC for sildenafil was 4.4 times higher than data from historical controls given either 50 mg or 100 mg of sildenafil and dose normalized to 25 mg. Indinavir was a potent inhibitor of sildenafil hepatic metabolism in vitro [concentration producing 50% inhibition of control enzyme activity (IC50) = 0.39 +/- 0.17 microM, mean +/- SD].. Co-administration of sildenafil 25 mg did not significantly alter the plasma indinavir levels. However, plasma sildenafil AUC was markedly increased in the presence of indinavir compared with historical controls. From the in vitro data, the mechanism of increase is indinavir inhibition of the hepatic metabolism of sildenafil. The magnitude of this interaction suggests a lower starting dose of sildenafil may be more appropriate in this clinical setting.

Topics: Adult; Drug Interactions; Erectile Dysfunction; HIV Infections; HIV Protease Inhibitors; Humans; Indinavir; Liver; Male; Middle Aged; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones

Impotence is often associated with protease inhibitor use, but much of the medical press ignored this issue until Spanish doctors described sexual difficulties following protease inhibitor therapy in 14 of 260 patients. Causes of sexual dysfunction in HIV-infected men are difficult to isolate but may also be traced to depression, physical weakness, opportunistic infections, stress, nerve damage, or hormonal imbalances. Pfizer, the manufacturer of Viagra, released study data on the effects of the drug used in combination with Ritonavir and Saquinavir; the data led Pfizer to alter Viagra dosing recommendations for people on protease inhibitors.

Topics: Adult; Drug Interactions; Erectile Dysfunction; HIV Infections; HIV Protease Inhibitors; Humans; Male; Middle Aged; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones

Viagra (sildenafil) must be used in low doses when used with protease inhibitors, especially Ritonavir. Antiretrovirals reduce the metabolism of sildenafil in the liver, resulting in abnormally high levels of sildenafil in the body. The combination does not affect the blood levels of the protease inhibitors. A maximum single dose of 25 mg of sildenafil per 48 hour period is recommended. Drug labeling also warns that anyone with an erection lasting more than four hours should seek immediate medical assistance to prevent permanent damage. Contact information is provided.

Topics: Drug Interactions; Erectile Dysfunction; HIV Infections; HIV Protease Inhibitors; Humans; Male; Nitrates; Piperazines; Purines; Sildenafil Citrate; Sulfones

The European Agency for the Evaluation of Medicinal Products (EMEA) issued a warning in April 1999, about potential adverse effects when the impotence drug sildenafil (Viagra) is taken with protease inhibitors. In particular, sildenafil and Ritonavir in combination results in significantly increased plasma levels of sildenafil for up to 24 hours after the drug is taken. There are similar reactions with other drugs, including Saquinavir, Erythromycin, and Itraconazole. The EMEA recommends that anyone taking protease inhibitors refrain from sildenafil, and that anyone taking sildenafil not exceed 25 mg in a 48-hour period.

Topics: Drug Interactions; Erectile Dysfunction; HIV Infections; HIV Protease Inhibitors; Humans; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones

Interactions between antiretrovirals and other drugs are a major concern for people with HIV/AIDS. Until the 39th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC), there was little information available on how common drugs interact with anti-HIV treatments. Several poster sessions described the common interactions with Viagra, antidepressants, and methadone.

Topics: Anti-HIV Agents; Antidepressive Agents, Second-Generation; Cyclohexanols; Drug Interactions; HIV Infections; Humans; Male; Methadone; Narcotics; Phosphodiesterase Inhibitors; Piperazines; Purines; Randomized Controlled Trials as Topic; Sildenafil Citrate; Sulfones

HIV-positive patients may experience erectile dysfunction and Viagra may be prescribed as a treatment. Viagra is processed by the P450 enzyme system and may negatively interact with other drugs, including protease inhibitors and non-nucleoside reverse transcriptase inhibitors (NNRTI). Protease inhibitors and delavirdine may increase Viagra levels and increase the risk of side effects. The NNRTIs efavirenz and nevirapine may lower levels of Viagra and reduce its effectiveness. The combination of Viagra with amyl nitrate can cause life-threatening drops in blood pressure.

Topics: Anti-HIV Agents; Erectile Dysfunction; HIV Infections; HIV Protease Inhibitors; Humans; Male; Piperazines; Purines; Reverse Transcriptase Inhibitors; Sildenafil Citrate; Sulfones

Users of Pfizer's anti-impotence drug, Viagra, should be aware that use with nitrates, such as poppers or nitroglycerin, can lead to dangerous drops in blood pressure. Viagra's effect on protease inhibitors is not known, however, drugs that strongly inhibit the CYP24A liver enzyme, such as ritonavir, will sharply retard Viagra's breakdown. It is recommended that persons taking ritonavir, and other similar acting drugs, start Viagra at 25 mg instead of the usual 50 mg dosage.

Topics: Blood Pressure; Drug Interactions; Erectile Dysfunction; HIV Infections; HIV Protease Inhibitors; Humans; Male; Phosphodiesterase Inhibitors; Piperazines; Purines; Sildenafil Citrate; Sulfones

Sildenafil, a recently approved drug, should not be used by people who are using organic nitrates, blood pressure medications, or certain HIV medications. Some protease inhibitors can increase sildenafil citrate levels in the blood. Drugs such as efavirenz and Nevirapine can reduce sildenafil levels. Other drugs and their effects are discussed.

Topics: Antibiotics, Antitubercular; Antifungal Agents; Drug Interactions; Enzyme Inhibitors; Erectile Dysfunction; HIV Infections; HIV Protease Inhibitors; Humans; Male; Piperazines; Purines; Reverse Transcriptase Inhibitors; Sildenafil Citrate; Sulfones