Sertindole for schizophrenia

Post-Marketing Regulation of Medicines Withdrawn from the Market Because of Drug-Attributed Deaths: An Analysis of Justification

INTRODUCTION

Several medicinal products have been withdrawn from the market because of drug-attributed deaths. However, there has been no investigation of whether such withdrawals were justified, and the extent to which confirmatory studies are used to investigate drug-adverse event relationships when deaths are reported is uncertain. We documented medicinal products withdrawn from the market because of drug-attributed deaths, identified confirmatory studies investigating the drug-adverse event relationships, examined whether withdrawals of medicinal products because of drug-attributed deaths after marketing were justified based on a mechanistic analysis, and examined the trends over time.

METHODS

We searched electronic and non-electronic sources to identify medicinal products that were withdrawn because of drug-attributed deaths. We used a previously published algorithm to examine whether the withdrawals of products were justified. We then searched PubMed and Google Scholar to identify studies investigating the drug-adverse event relationships, used the Oxford Centre for Evidence-Based Medicine criteria to document the levels of evidence, and assessed whether the evidence of an association was confirmed.

RESULTS

We included 83 medicinal products. The reasons for withdrawal appeared to have been justified in 80 cases (96%). The median interval between the first reported adverse reaction that was related to the cause of death and the first reported death was 1 year (interquartile range = 1-3); products were withdrawn sooner when the interval between the first reported relevant adverse reaction and the first death was shorter. Confirmatory studies were conducted in 57 instances (69%), and there was evidence of an association in 52 cases (63%). Four products (5%) were re-introduced after initial withdrawal.

CONCLUSION

Regulatory authorities have been justified in making withdrawal decisions when deaths have been attributed to medicinal products, using the precautionary principle when alternative decisions could have been made. Medicinal products are likely to be quickly withdrawn from the market when there is a short interval to the first reported deaths. The use of an algorithm such as we have used in this study could help to expedite the process of decision making.

The influence of atypical antipsychotic drugs on sexual function

Human sexuality is contingent upon many biological and psychological factors. Such factors include sexual drive (libido), physiological arousal (lubrication/erection), orgasm, and ejaculation, as well as maintaining normal menstrual cycle. The assessment of sexual dysfunction can be difficult due to the intimate nature of the problem and patients' unwillingness to discuss it. Also, the problem of dysfunction is often overlooked by doctors. Atypical antipsychotic treatment is a key component of mental disorders' treatment algorithms recommended by the National Institute of Health and Clinical Excellence, the American Psychiatric Association, and the British Society for Psychopharmacology. The relationship between atypical antipsychotic drugs and sexual dysfunction is mediated in part by antipsychotic blockade of pituitary dopamine D2 receptors increasing prolactin secretion, although direct correlations have not been established between raised prolactin levels and clinical symptoms. Variety of mechanisms are likely to contribute to antipsychotic-related sexual dysfunction, including hyperprolactinemia, sedation, and antagonism of a number of neurotransmitter receptors (α-adrenergic, dopaminergic, histaminic, and muscarinic). Maintaining normal sexual function in people treated for mental disorders can affect their quality of life, mood, self-esteem, attitude toward taking medication, and compliance during therapy.

Analysis of West Virginia medicaid claims data for the prevalence of medical conditions and use of drugs likely to cause QT prolongation in patients with schizophrenia

BACKGROUND

An important concern with antipsychotic drugs used for the treatment of schizophrenia is the prolongation of the QT interval on the electrocardiogram. Concomitant use of other QT-prolonging drugs and the presence of certain medical conditions may lead to excessive QT prolongation and subsequent cardiac arrhythmias.

OBJECTIVE

The aim of this study was to assess the utilization of QT-prolonging drugs and the prevalence of medical conditions causing QT prolongation in a large population of patients with schizophrenia in practice settings.

METHODS

The study was conducted using West Virginia Medicaid claims data for patients aged 18 to 64 years with ≥1 medical claim for schizophrenia between January 1, 1997, and December 31, 1999. A comprehensive list of drugs and medical conditions causing QT prolongation was obtained from the literature. The drugs were identified in the prescription claims data using their specific National Drug Classification codes. Codes from the International Classification of Diseases, Ninth Revision, Clinical Modification, were used to identify the medical conditions as described in the medical claims files. Descriptive statistics on utilization of drugs and prevalence of medical conditions were reported and demographic differences were examined.

RESULTS

The final sample consisted of 1699 patients with schizophrenia. The mean (SD) age was 40.8 (11.35) years (range, 18-63 years); 55% of the patients were women. A total of 76.9% of patients utilized ≥1 nonantipsychotic QT-prolonging drug in a year, with a mean (SD) of 2.1 (1.3) such drugs used per patient per year. A total of 15.9% of patients with schizophrenia had ≥1 medical condition associated with QT prolongation. Patients with ≥1 such medical condition had a mean (SD) of 1.2 (0.57) conditions potentially causing QT prolongation. The number of nonantipsychotic QT-prolonging prescriptions filled and the prevalence of medical conditions leading to QT prolongation were found to be significantly higher for women (both P<0.001) and patients aged 34 to 64 years (both P<0.001).

CONCLUSIONS

In this study, a high utilization of QT-prolonging drugs and the prevalence of medical conditions causing QT prolongation were found. These results merit assessment of predisposing risk factors, such as concurrent use of other QT-prolonging drugs and the presence of cardiovascular and other conditions associated with QT prolongation, before prescribing antipsychotics, especially in women and older patients with schizophrenia.

Drug-induced block of cardiac HERG potassium channels and development of torsade de pointes arrhythmias: the case of antipsychotics

The prolongation of the cardiac repolarization process, a result of the blocking of the Human Ether-a-go-go Related Gene potassium channel, is an undesired accessory property shared by many pharmacological classes of non-cardiovascular drugs. Often the delayed cardiac repolarization process can be identified by a prolongation of the QT interval of the electrocardiograph. In these conditions, premature action potentials can trigger a dangerous polymorphic ventricular tachyarrhythmia, known as torsade de pointes, which occasionally can result in lethal ventricular fibrillation. In this work, brief descriptions of the electrophysiological basis of torsade de pointes and of the several pharmacological classes of torsadogenic drugs are given. Attention is focused on antipsychotics, with a deeper overview on the experimental and clinical reports about their torsadogenic properties.

The atypical antipsychotic drug clozapine enhances chronic PCP-induced regulation of prefrontal cortex 5-HT2A receptors

The ability of antipsychotic drugs to affect 5-HT(2A) receptor function has been widely suggested to contribute to their therapeutic properties. We have compared the ability of the antipsychotic drugs clozapine and haloperidol, alone and in combination with chronic phencyclidine (PCP), to modulate 5-HT(2A) receptor binding and mRNA. Acute (i.p. 45 min) and chronic (21-day) clozapine (osmotic minipump (OMP); 20 mg/kg/day) produced widespread decreases in 5-HT(2A) receptor binding (-60%-80%), measured using [(3)H]ketanserin autoradiography. Conversely, 5-HT(2A) mRNA levels, determined using in-situ hybridisation, were modestly increased by chronic clozapine treatment (+10%-30%). Chronic PCP treatment, at a dose (2.58 mg/kg i.p. intermittently for 28 days) that reproduces many of the neurochemical deficits of schizophrenia, decreased 5-HT(2A) receptor binding in the prefrontal cortex (PFC; -16%), consistent with the changes in post-mortem brain tissue from schizophrenic patients. Combined chronic PCP (i.p.) and clozapine (OMP) treatment down-regulated 5-HT(2A) receptor binding in many areas, similar to the effects of clozapine treatment alone and clozapine further enhanced the effects of PCP in the prefrontal cortex. In contrast 5-HT(2A) mRNA was not altered. Haloperidol treatment alone (1 mg/kg/day; OMP) and in combination with PCP (i.p.), generally produced no changes in 5-HT(2A) receptor protein or mRNA. Hence chronic PCP treatment, as employed here, mimics the decreased 5-HT(2A) receptor binding observed in the PFC of schizophrenic patients. Clozapine's enhancement of the natural response of PCP to down-regulate PFC 5-HT(2A) receptors may contribute to it's improved therapeutic profile against negative symptoms and cognitive deficits.

The new and evolving pharmacotherapy of schizophrenia

Based on the evidence presented here, the following tentative conclusions can be drawn. Atypical antipsychotics (except amisulpride) have shown superiority over placebo in acute schizophrenia. Compared with conventional antipsychotics, they are at least as effective. Generally, analyses employing conservative criteria (e.g., Cochrane reviews) report few efficacy differences between atypical and conventional agents. There are now many well-controlled studies indicating modest advantages for the atypical antipsychotics, however, particularly in specific symptom domains. For the treatment of negative symptoms, olanzapine and to a lesser extent amisulpride seem most promising. Risperidone, olanzapine, and quetiapine display advantages in improving cognitive and depressive symptoms. There are indications that the atypical antipsychotics are associated with decreased likelihood of rehospitalization and improved quality of life. In head-to-head comparisons of atypical antipsychotics, none have shown consistent efficacy advantages. In severely refractory samples, no atypical antipsychotics have consistently been shown to be as effective as clozapine or superior to conventional agents. There are indications, however, that risperidone, olanzapine, and quetiapine have advantages over conventional agents in less severely refractory patients. Few maintenance RCTs have been published, and efficacy advantages for atypical antipsychotics in prospective RCTs in first-episode schizophrenia have not been reported.