Correlates of high-dose antipsychotic prescription amongst outpatients with Schizophrenia in a Nigerian Hospital

Abstract

Background Treatment guidelines recommend the use of antipsychotic monotherapy at effective doses for the treatment of schizophrenia, although about a third of the sufferers still receive high-dose antipsychotic treatment. Current evidence suggests that high-dose antipsychotic prescription (HDAP) not only fails to improve outcomes but also increases side effects. Aim Our study aimed to determine the prevalence of HDAP and its association with illness severity, medication adherence behaviour and side effects amongst outpatients with schizophrenia. Setting The Federal Neuro-Psychiatric Hospital, Benin-City, Nigeria. Methods A cross-sectional study of 320 attendees with schizophrenia at the outpatient department was undertaken. We administered a sociodemographic and antipsychotic medication questionnaire, Mini-International Neuropsychiatric Interview, Positive and Negative Syndrome Scale, Liverpool University Neuroleptic Side Effects Rating Scales and Medication Adherence Rating Scales. High-dose antipsychotic prescription was determined by the ratio of prescribed daily dose to defined daily dose greater than 1.5. Results The prevalence of HDAP was 38.4%. Greater severity of illness, experiencing more side effects and poor medication adherence were significantly associated with HDAP.The major predictors of HDAP were antipsychotic polypharmacy and concurrent anticholinergic use. Conclusion We conclude that although the use of HDAP amongst patients with schizophrenia remains common, its persistent use should be discouraged.