fluvoxamine and Long-QT-Syndrome

When predicting the effects of medication for psychiatric diseases and their side effects based on genetic information, there are many things to consider besides just genetic information, including the index to be evaluated. We have shown before that it is important to simultaneously analyze both pharmacokinetic factors such as the blood concentration and pharmacodynamic factors such as the site of drug action, when searching for genetic information that can be used to predict the treatment effects of fluvoxamine for depression and its side effects. For example, we have shown that there exists a specific concentration that can be used to predict remission in the treatment of depression with fluvoxamine (Fukui et al, 2008); however, it is considered that without a sufficient examination of such factors besides genetic information, it is difficult to predict the effects using just genetic information. On the other hand, the situation is more complex with medication for schizophrenia. Although it appears that consensus has been obtained in that the goal of medication for depression is remission, the goal of medication for schizophrenia is not clear and it cannot be said that prediction studies on the effects have been sufficiently conducted using genetic information. Therefore, at our facility, focusing on metabolic anomalies due to antipsychotics, QT prolongation, and hyperprolactinemia, which have become issues in recent years, a prediction study on side effects was conducted. Because such side effects can be quantified, in comparison with the effects study, it is advantageously simple to examine the relationship with genetic information. However, in the course of this study, we discovered that there was a gender difference in terms of glycolipid metabolic anomalies, that antipsychotics particularly extended the QT interval during nighttime, and that prolactine following the administration of antipsychotics temporally increased before declining again a few weeks later. We believe that when examining the relationship between side effects and genetic information, the genetic information may not be sufficiently utilized unless the analysis is performed after obtaining a better understanding of the characteristics of such side effects.

Topics: Adult; Antidepressive Agents, Second-Generation; Female; Fluvoxamine; Glycolipids; Humans; Hyperprolactinemia; Long QT Syndrome; Male; Metabolic Syndrome; Middle Aged; Pharmacogenetics; Polymorphism, Genetic; Precision Medicine; Receptors, Dopamine D2; Schizophrenia; Selective Serotonin Reuptake Inhibitors; Young Adult

QT interval prolongations were described with citalopram and escitalopram. However, the effects of the other serotonin reuptake inhibitors (SRIs) remained discussed. In order to identify a putative signal with other SRIs, the present study investigates the reports of QT interval prolongation with SRIs in two pharmacovigilance databases (PVDB).. Two kinds of investigations were performed: (1) a comparative study in VigiBase®, the WHO PVDB, where notifications of QT prolongation with six SRIs (citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine, sertraline) were selected. Cases with overdose or pregnancy were excluded. The relationship between the "suspected" SRI and occurrence of QT prolongation was assessed by calculating reporting odds ratio (ROR) in a case/non-case design. (2) A descriptive study of QT prolongation reports with citalopram and escitalopram in the French FPVD.. In VigiBase®, 855 notifications were identified (mean age 56.2 years, mainly women 73%). Among them, 172 (20.1%) were associated to escitalopram; 299 (35.0%), to citalopram; 186 (21.8%), to fluoxetine; 94 (11.0%), to sertraline; 66 (7.7%), to paroxetine; and 38 (4.4%) to fluvoxamine. A significant ROR value (higher than 1) was only found for citalopram (3.35 CI95% [2.90-3.87]) or escitalopram (2.50 [2.11-2.95]). In the FPVD, eight reports of QT prolongation were found with citalopram and 27 with escitalopram, mainly in women (77.1%) with a mean age of 73.2 years. In 23 cases (66%), SRIs were associated with other suspected drugs, mainly cardiotropic or psychotropic ones. Hypokalemia was associated in six patients.. This study, performed in real conditions of life, shows a clear signal of QT prolongation with only two SRIs, citalopram and escitalopram, indicating that QT prolongation is not a SRI class effect.

Topics: Adult; Aged; Arrhythmias, Cardiac; Citalopram; Databases, Factual; Female; Fluvoxamine; Humans; Long QT Syndrome; Male; Middle Aged; Paroxetine; Pharmacovigilance; Selective Serotonin Reuptake Inhibitors; Sertraline

Fluvoxamine is one of the typical selective serotonin-reuptake inhibitors. While its combined use with QT-prolonging drugs has been contraindicated because of the increase in plasma concentrations of such drugs, information is still limited whether fluvoxamine by itself may directly prolong the QT interval. We examined electropharmacological effects of fluvoxamine together with its pharmacokinetic profile by using the halothane-anesthetized dogs (n = 4). Fluvoxamine was intravenously administered in three escalating doses of 0.1, 1 and 10 mg/kg over 10 min with a pause of 20 min between the doses. The low dose provided therapeutic plasma drug concentration, whereas the middle and high doses attained approximately 10 and 100 times of the therapeutic ones, respectively. Supra-therapeutic concentration of fluvoxamine exerted the negative chronotropic, inotropic and hypotensive effects; and suppressed the atrioventricular nodal and intraventricular conductions, indicating inhibitory actions on Ca2+ and Na+ channels, whereas it delayed the repolarization in a reverse use-dependent manner, reflecting characteristics of rapidly activating delayed rectifier K+ current channel-blocking property. Fluvoxamine prolonged the terminal repolarization phase at 100 times higher concentration than the therapeutic, indicating its proarrhythmic potential. Thus, fluvoxamine by itself has potential to directly induce long QT syndrome at supra-therapeutic concentrations.

Topics: Animals; Arrhythmias, Cardiac; Calcium Channels; Contraindications; Depression, Chemical; Dogs; Dose-Response Relationship, Drug; Fluvoxamine; Heart Conduction System; Heart Rate; Hypotension; Infusions, Intravenous; Long QT Syndrome; Male; Myocardial Contraction; Selective Serotonin Reuptake Inhibitors; Sodium Channels

The human ether-a-go-go-related gene (hERG) voltage-gated K(+) channels are located in heart cell membranes and hold a unique selectivity filter (SF) amino acid sequence (SVGFG) as compared to other K(+) channels (TVGYG). The hERG provokes the acquired long QT syndrome (ALQTS) when blocked, as a side effect of drugs, leading to arrhythmia or heart failure. Its pore domain - including the SF - is believed to be a cardiotoxic drug target. In this study combining solution and solid-state NMR experiments we examine the structure and function of hERG's L(622)-K(638) segment which comprises the SF, as well as its role in the ALQTS using reported active drugs. We first show that the SF segment is unstructured in solution with and without K(+) ions in its surroundings, consistent with the expected flexibility required for the change between the different channel conductive states predicted by computational studies. We also show that the SF segment has the potential to perturb the membrane, but that the presence of K(+) ions cancels this interaction. The SF moiety appears to be a possible target for promethazine in the ALQTS mechanism, but not as much for bepridil, cetirizine, diphenhydramine and fluvoxamine. The membrane affinity of the SF is also affected by the presence of drugs which also perturb model DMPC-based membranes. These results thus suggest that the membrane could play a role in the ALQTS by promoting the access to transmembrane or intracellular targets on the hERG channel, or perturbing the lipid-protein synergy.

Topics: Bepridil; Cetirizine; Dimyristoylphosphatidylcholine; Diphenhydramine; ERG1 Potassium Channel; Ether-A-Go-Go Potassium Channels; Fluvoxamine; Humans; Ion Channel Gating; Long QT Syndrome; Magnetic Resonance Spectroscopy; Membranes, Artificial; Phosphatidylcholines; Potassium; Promethazine; Protein Conformation; Structure-Activity Relationship

Topics: Anti-Anxiety Agents; Cognition Disorders; Epilepsy; ERG1 Potassium Channel; Ether-A-Go-Go Potassium Channels; Female; Fluvoxamine; Humans; Long QT Syndrome; Middle Aged; Multiple Sclerosis; Obsessive-Compulsive Disorder; Potassium Channel Blockers; Schizophrenia; Selective Serotonin Reuptake Inhibitors; Treatment Outcome

Topics: Adolescent; Anxiety Disorders; Electrocardiography; Female; Fluvoxamine; Humans; Long QT Syndrome; Selective Serotonin Reuptake Inhibitors