Adverse drug reactions experienced by out-patients taking chlorpromazine or haloperidol at Zomba Mental Hospital, Malawi

Objective: Drugs for managing mental disorders can cause adverse drug reactions (ADRs) that have negative impacts on patients yet, in Malawi, epidemiological data on the drug-related problems are limited. This study assessed the prevalence and severity of ADRs in out-patients at Zomba Mental Hospital. Results: Twenty-six of forty patients (65.0%) were taking haloperidol and 14 (35.0%) chlorpromazine. The commonest diagnosis was schizophrenia (n = 23, 57.5%) followed by epileptic psychosis (n = 4, 10.0%) and general psychosis (n = 4, 10.0%) with one of psychotic depression and one psychosis secondary to general medical condition. Comorbidities were also found with epilepsy being the commonest (n = 4, 10.0%). All patients reported at least one ADR of varying severity (mild, moderate and severe). Polydipsia was the most prevalent (24, 60.0%) followed by weight gain (20, 50.0%), spasm (15, 37.5%) and xerostomia (15, 37.5%). Some ADRs were gender specific and these included impotence (6/27, 29.6%) for males and menstrual changes (3/14, 21.4%) for females. Severe ADRs were more common in the older aged group (> 35 years 8.3% vs 7.1%), in males (11.1% vs 0.0%) and on chlorpromazine (14.3% vs 3.8%). Patients taking chlorpromazine and haloperidol are at risk of experiencing a wide range of ADRs with varying degrees of severity.