pyrantel-pamoate and Necatoriasis

Topics: Ancylostoma; Ancylostomiasis; Animals; Antinematodal Agents; Diagnosis, Differential; Humans; Intestinal Diseases, Parasitic; Mebendazole; Necator americanus; Necatoriasis; Prognosis; Pyrantel Pamoate

Topics: Anthelmintics; Ascariasis; Benzimidazoles; Child; Costs and Cost Analysis; Drug Administration Schedule; Female; Humans; Intestinal Diseases, Parasitic; Levamisole; Male; Mebendazole; Necatoriasis; Pyrantel; Pyrantel Pamoate; Trichuriasis

Topics: Adult; Benzimidazoles; Clinical Trials as Topic; Female; Hookworm Infections; Humans; Male; Mebendazole; Necatoriasis; Pyrantel; Pyrantel Pamoate; Tetrachloroethylene; Thailand

Topics: Adolescent; Adult; Aged; Child; Child, Preschool; Clinical Trials as Topic; Drug Evaluation; Female; Hookworm Infections; Humans; Male; Middle Aged; Necatoriasis; Pyrantel; Pyrantel Pamoate; Tablets

The clearance of hookworm (Necator americanus) ova by a single dose of tetrachlorethylene (T.C.E.) was compared with that produced by single and multiple dose regimes of bephenium hydroxynaphthoate and pyrantel pamoate. Single doses of bephenium and pyrantel were inferior to T.C.E. Three daily doses of bephenium or pyrantel produced effects comparable with a single dose of T.C.E. Because of the low cost and lack of side effects, T.C.E. remains the drug of choice in the treatment of N. americanus in infections; the only disadvantage of T.C.E. is its unnoticed deterioration under tropical conditions.

Topics: Administration, Oral; Adult; Bephenium Compounds; Body Weight; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Evaluation; Feces; Hemoglobins; Hookworm Infections; Humans; Necator; Necatoriasis; Pyrantel; Pyrantel Pamoate; Sri Lanka; Tetrachloroethylene

It is widely recognized that only a handful of drugs are available against soil-transmitted helminthiasis, all of which are characterized by a low efficacy against Trichuris trichiura, when administered as single doses. The re-evaluation of old, forgotten drugs is a promising strategy to identify alternative anthelminthic drug candidates or drug combinations.. We studied the activity of the veterinary drug oxantel pamoate against Trichuris muris, Ancylostoma ceylanicum and Necator americanus in vitro and in vivo. In addition, the dose-effect of oxantel pamoate combined with albendazole, mebendazole, levamisole, pyrantel pamoate and ivermectin was studied against T. muris in vitro and additive or synergistic combinations were followed up in vivo.. We calculated an ED50 of 4.7 mg/kg for oxantel pamoate against T. muris in mice. Combinations of oxantel pamoate with pyrantel pamoate behaved antagonistically in vitro (combination index (CI) = 2.53). Oxantel pamoate combined with levamisole, albendazole or ivermectin using ratios based on their ED50s revealed antagonistic effects in vivo (CI = 1.27, 1.90 and 1.27, respectively). A highly synergistic effect (CI = 0.15) was observed when oxantel pamoate-mebendazole was administered to T. muris-infected mice. Oxantel pamoate (10 mg/kg) lacked activity against Ancylostoma ceylanicum and Necator americanus in vivo.. Our study confirms the excellent trichuricidal properties of oxantel pamoate. Since the drug lacks activity against hookworms it is necessary to combine oxantel pamoate with a partner drug with anti-hookworm properties. Synergistic effects were observed for oxantel pamoate-mebendazole, hence this combination should be studied in more detail. Since, of the standard drugs, albendazole has the highest efficacy against hookworms, additional investigations on the combination effect of oxantel pamoate-albendazole should be launched.

Topics: Ancylostoma; Ancylostomiasis; Animals; Anthelmintics; Disease Models, Animal; Drug Synergism; Drug Therapy, Combination; Female; Mice; Mice, Inbred C57BL; Necator americanus; Necatoriasis; Parasitic Sensitivity Tests; Pyrantel Pamoate; Treatment Outcome; Trichuriasis; Trichuris

Laboratory golden hamsters (Mesocricetus auratus) were infected with Necator americanus under several different parasite and host conditions to optimize the model for testing anthelminthic drugs. The results confirmed that male hamsters were more susceptible to infection than females. Host age in the range of 5-15 weeks was not a factor that impacted on adult worm burden, and similar worm burdens were achieved using doses of 150, 250 or 500 N. americanus L3 (NaL3). The largest numbers of adult hookworms were recovered on days 21-28 post-infection, with a significant decrease at days 40-50 post-infection. Therefore adult worm recovery is maximal approximately 11-18 days prior to patency and host blood loss. From these studies a drug evaluation protocol was developed using 150 NaL3 as the infectious dose and then evaluating the anthelminthic effects of the drugs albendazole, tribendimidine, and pyrantel pamoate on days 21-28 post-infection. The model confirms the anthelminthic activity of albendazole, tribendimidine, and pyrantel pamoate and has the potential as a laboratory animal model to detect emerging drug resistance.

Topics: Age Factors; Albendazole; Animals; Anthelmintics; Cricetinae; Disease Models, Animal; Erythrocyte Count; Female; Male; Mesocricetus; Necator americanus; Necatoriasis; Phenylenediamines; Pyrantel Pamoate; Sex Factors

Three different control schemes including selective chemotherapy, a combination of selective chemotherapy and management of fecal disposal and mass treatment with mebendazole-medicated salt were implemented for the control of hookworm infection in Luwo Town and Taiping Village, Wuming County, Guangxi Zhuang Autonomous Region during 1971-1990. Through ten years of selective chemotherapy, the results showed that the hookworm infection rate dropped from 42.6% to 3.9% and the infection intensity from 425.6 eggs per gram faeces to 1.6 eggs per gram faeces. After seven years of selective chemotherapy combined with management of fecal, the hookworm infection rate dropped from 58.7% to 10.9% and the infection intensity from 111.5 eggs per gram faeces to 8.5 eggs per gram faeces. However, 3 years after the termination of the combined treatment, the hookworm infection rate increased to 14.5%. As for the implementation of the third scheme, mebendazole-medicated salt was given at 100 mg daily for 30 consecutive days or at 50 mg daily for 30 consecutive days. Stool examination was made one year after the treatment, the results showed that the infection rate of the inhabitants dropped from 36% and 36% to 2% and 1.3%, respectively, and the infection intensity dropped from 110.3 and 246 eggs per gram faeces to 1.3 and 0.24 eggs per gram faeces. After three years, the infection rate of inhabitants remained under 2% and the infection intensity under 1 egg per gram faeces. It was concluded that mass treatment with mebendazole-medicated salt might be the most practical scheme for the control of hookworm infection.

Topics: Ancylostomiasis; Animals; Bephenium Compounds; Humans; Levamisole; Mebendazole; Necator americanus; Necatoriasis; Pyrantel Pamoate

Reinfection with hookworm (Necator americanus) following chemotherapy was studied over 2 years in a rural village in Madang Province, Papua New Guinea. The prevalence of hookworm infection had returned to pre-treatment levels after 2 years, and the geometric mean hookworm burden had returned to 58% of the pre-treatment value. The rate of acquisition of adult worms was independent of host age, and was estimated as a geometric mean of 2.9-3.3 worms/host/year (arithmetic mean 7.9-8.9 worms/host/year). There was significant predisposition to hookworm infection; the strength of this predisposition did not vary significantly between age or sex classes.

Topics: Age Factors; Animals; Ascariasis; Causality; Female; Humans; Incidence; Male; Necator americanus; Necatoriasis; Papua New Guinea; Pyrantel Pamoate; Recurrence; Sex Factors; Time Factors; Trichuriasis

Adult Necator americanus infection in laboratory hamsters (the hamster-hookworm model) was examined as an anthelminthic screening system. Three reference anthelminthics--pyrantel (PYTL), mebendazole (MBZ) and ivermectin (IVRN)--were used to assess the sensitivity of adult N. americanus and also to investigate the value of the hamster-hookworm model for predicting clinical results. Serial drug dosages were used, and the ED50 was determined from the resulting cure rates. In addition, percentage worm reductions were calculated by reference to the worm burdens in control groups. The results showed that the hamster-hookworm model was able to differentiate anthelminthics on their efficacy. Absolute activity (100% worm reduction) followed treatment with 8 mg kg-1 MBZ, 38-40 mg kg-1 PYTL and 18 mg kg-1 IVRN. Based on ED50 data of PYTL and MBZ, adult N. americanus appeared to be two to five times more sensitive than pre-adult stages. However, with IVRN the reverse appeared true. MBZ appeared to be most active and PYTL least active in terms of curing infected animals, but there were no obvious differences between the rates of worm reductions following single or multiple doses of anthelminthics. It is considered that the hamster-hookworm model will prove of value in identifying and characterizing possible new anthelminthics.

Topics: Animals; Cricetinae; Disease Models, Animal; Humans; Ivermectin; Mebendazole; Mesocricetus; Necator; Necatoriasis; Pyrantel; Pyrantel Pamoate; Random Allocation

Hookworm infections, as assessed by counting worms expelled following anthelmintic treatment and by egg output, were found to be of low prevalence and intensity in a South Indian fishing community. The initial overall prevalence of infection in the community was 43%, and the average burden was estimated at 2.2 hookworms per person. The age profiles of prevalence and intensity differed between males and females, with the latter harbouring significantly higher levels of infection. Children of both sexes under 10 years of age rarely harboured hookworms. Treatment with pyrantel pamoate was estimated to be 91% effective in clearing hookworm infections. Egg counts made on stools collected during an 11-month period of reinfection indicated that female patients became reinfected soon after treatment, while little hookworm egg excretion was observed in males during the observation period following treatment. Females acquired a significantly higher number of worms during the reinfection period compared with males, although the average burden in females reached only 28% of the initial, pre-treatment level. The hookworm population consisted of predominantly Necator americanus, and less than 10% of Ancylostoma duodenale. The parasites were highly aggregated within the host population with 10% of the community harbouring over 65% of the total hookworms. Low values of the negative binomial aggregation parameter, k, (indicating extreme over-dispersion) were recorded in groups stratified by age and sex. Highly significant positive correlations were observed between the initial (pre-treatment) and reinfection worm burdens of female (but not of male) patients. It is suggested that occupational practices related to walking through areas contaminated with hookworm larvae play an important role in generating the observed patterns of infection within this community.

Topics: Adult; Age Factors; Ancylostoma; Ancylostomiasis; Animals; Child; Child, Preschool; Disease Susceptibility; Feces; Female; Humans; India; Male; Middle Aged; Necator; Necatoriasis; Parasite Egg Count; Pyrantel; Pyrantel Pamoate; Recurrence

Topics: Ancylostomiasis; Animals; Anthelmintics; Cricetinae; Dogs; Necatoriasis; Nematode Infections; Nippostrongylus; Phenylenediamines; Pyrantel Pamoate; Rats

A mixture of 150 mg mebendazole and 30mg pyrantel pamoate was given on 3 consecutive or near-consecutive days to 70 children infected with one or more of Necator americanus, Ascaris lumbricoides, Strongyloides stercoralis, S. fuelleborni-like and Trichuris trichiura. This treatment had an efficacy of 95 per cent for N. americanus infections, 100 per cent for A. lumbricoides, 57 per cent for Strongyloides spp., and 75 per cent for T. trichiura. The results indicate that the treatment given is effective against the infections of N. americanus and A. lumbricoides but is only partially effective for Strongyloides and T. trichiura infections.

Topics: Ascariasis; Benzimidazoles; Child, Preschool; Drug Therapy, Combination; Humans; Infant; Mebendazole; Necatoriasis; Nematode Infections; Papua New Guinea; Pyrantel; Pyrantel Pamoate; Strongyloidiasis; Trichuriasis

Topics: Adolescent; Adult; Aged; Benzimidazoles; Bephenium Compounds; Female; Humans; Kenya; Male; Mebendazole; Middle Aged; Necatoriasis; Pyrantel; Pyrantel Pamoate

A mixture of oxantel-pyrantel pamoate was given to 147 primary school children. A single daily dose of 15 mg per kg body weight was administered to cases with Ascaris lumbricoides and Trichuris trichiura infections. The same single daily dose was given for three consecutive days to 10 cases with hookworm infections. The cure rate was 93.7% for ascariasis and the egg reduction rate was 98.2%. A cure rate and an egg reduction rate for trichuriasis was 70.2% and 86.5% respectively. All cases with hookworm infection were cured. Side effects were light and did not cause any anxiety.

Topics: Adolescent; Ascariasis; Child; Drug Therapy, Combination; Humans; Indonesia; Necatoriasis; Parasite Egg Count; Pyrantel; Pyrantel Pamoate; Trichuriasis

Topics: Adolescent; Adult; Antinematodal Agents; Ascariasis; Benzimidazoles; Child; Child, Preschool; Drug Administration Schedule; Drug Combinations; Drug Therapy, Combination; Female; Humans; Intestinal Diseases, Parasitic; Male; Mebendazole; Necatoriasis; Nematode Infections; Pyrantel; Pyrantel Pamoate; Trichuriasis