The pharmacovigilance of olanzapine: results of a post-marketing surveillance study on 8858 patients in England

Abstract

Olanzapine is an 'atypical' antipsychotic indicated for the treatment of schizophrenia. We analysed adverse events (AEs) reported in primary practice in England. Dispensed prescriptions issued between December 1996 and May 1998 provided exposure data. Questionnaires sent to general practitioners provided outcomes. Frequently reported AEs were: drowsiness/sedation (n = 19), extrapyramidal disorder (n = 13) and unspecified side-effects (n = 33). Events with highest incidence density in first month and reason for stopping were: drowsiness/sedation [n = 153, incidence density (ID)1 18.9], weight gain (n = 117, ID1 8.9) and malaise/lassitude (n = 65, ID1 5.2). Extrapyramidal disorders were more common in elderly population (> 70 years, ID1 3.6, risk 26.0 per 1,000 patients) compared to < 70 years (ID1 1.1, risk 8.4 per 1,000 patients). Serious suspected adverse reactions were neuroleptic malignant syndrome (n = 1) and angioneurotic ooedema (n = 2). There were eight reports of diabetes mellitus assessed as possibly due to olanzapine. Diabetes mellitus was an unlabelled AE and possible signal generated by prescription-event monitoring.

Assessment of independent effect of olanzapine and risperidone on risk of diabetes among patients with schizophrenia: population based nested case-control study

“…Recent evidence has shown an association between olanzapine and diabetes 7 – 14. Most of the articles were case reports documenting the incidence of diabetes or hyperglycaemia with olanzapine.…”

Assessing and Reporting the Adverse Effects of Antipsychotic Medication

“…hyperprolactinaemia 24 ), or the safety and tolerability profiles for particular classes (e.g. long-acting injections 25 ) or brands 26 of drug. However, there is currently a lack of comprehensive information about the methods employed for assessing adverse antipsychotic effects across the broader evidence base (including, but not limited to, clinical trials), the types of effects being reported, and whether screening procedures differ according to the effects being assessed.…”

The Bidirectional Relationship Between Psychiatry and Type 2 Diabetes Mellitus

“…Two other studies which included clozapine found no increased DM risk (Lund et al, 2001 andWang et al, 2001), while Sernyak et al (2002) and Gianfrancesco et al (2002) both suggested that patients on clozapine had a greater risk of developing DM than those on conventional antipsychotics or non-users of antipsychotics. The report by Biswasl et al (2001) found only eight cases of diabetes among 8858 patients onolanzapine between 1996 and 1998 reported by responding clinicians to a pharmacovigilance questionnaire. Among the clinical studies, five found that the use of olanzapine was associated with a significantly greater risk of increasing blood glucose or insulin levels compared to those on risperidone or a control group (Melkersson and Hulting, 2001;Newcomer et al, 2002;Wirshing et al, 2002;Lindenmayer et al, 2003).…”