BackgroundAntipsychotic medications are considered to be the mainstay treatment for schizophrenia. Overall, 50-75% of patients with schizophrenia will relapse within a year if their antipsychotics are discontinued, compared with just 25% of patients who continue their medications. Thus, understanding drug-related determinants of medication adherence is one of the critical issues for relapse prevention.
AimThe aim of the present study was to estimate the rate of nonadherence and to assess medication-related extrapyramidal and weight-gain side effects influencing adherence to antipsychotic drugs.
Patients and methodsThe present study included 109 patients recruited from Ain Shams University Institute of Psychiatry, Egypt. They were interviewed using the Structured Clinical Interview for DSM-IV (SCID), and diagnosed according to DSM-IV. Demographic data and weight were assessed upon enrollment. They received antipsychotic medication with a dose range of 280-300 mg chlorpromazine equivalent, and were followed up for 6 months. At the end of this period, adherence to medication was assessed using the Brief Adherence Rating Scale and the side effects of antipsychotics; accordingly, we had an adherent (n = 34) and a nonadherent group (n = 74). Side effects of antipsychotics were assessed using the Simpson Angus Scale (for extrapyramidal symptoms), Barnes Rating Scale (for akathisia), and Abnormal Involuntary Movement Scale (for dyskinesia). Finally, patients' weights were again measured.
ResultsOverall, 68.8% of the patients were nonadherent to their antipsychotic medications. An analysis of the different variables that could affect adherence revealed that females and university graduates significantly were more adherent (P = 0.04, 0.02, respectively). We did not find any statistically significant difference between the adherent and nonadherent groups regarding the type of antipsychotics prescribed and weight gained (P40.05). Experiencing motor side effects had significant relation to adherence as the presence of dyskinesia, akathisia, and extrapyramidal symptoms lead to nonadherence (P = 0.014, 0.017, 0.00, respectively). The studied risk factors did not yield any drug-related predictors for nonadherence, probably because of the small sample size.
ConclusionThe rate of nondrug adherence was relatively high. Females and university educated patients were more adherent to treatment. There was no relation between type of antipsychotic prescribed and drug compliance; however, experiencing motor side effects might be a driving component for nonadherence. This information may help clinicians to make proper interventional decisions to maximize drug adherence.