Drug utilization patterns of antidepressants in Federal Neuro-Psychiatric Hospital Lagos, Nigeria

Backgroud: The paucity of information on prescribing patterns and use of antidepressants in accordance with practice guidelines necessitated this study in Nigeria.Objective: To assess the prescribing patterns of antidepressants, average cost of prescriptions and the index of rational drug prescribing (IRDP) in a Nigerian tertiary care hospital.Methods: A retrospective study which involved the assessment of 683 prescriptions and case records of patients who received antidepressants from 1st January 2013 to 31st December 2014 was conducted. Information on diagnosis, patients’ demographics, prescribing patterns and cost of medications was obtained therefrom. Compliance to the World Health Organization (WHO) prescribing indicators and Nigerian Standard Treatment Guidelines (STG) was assessed. The IRDP for antdepressants was determined using a validated mathematical model. The statistical analysis was performed using SPSS version 20.Results: Tricyclic antidepressants (TCAs) were the most commonly prescribed drug group (61.3%), followed by selective serotonin re-uptake inhibitors (SSRIs) with a total of 38.7%. On the average, three drugs were prescribed per prescription, while 60.3% and 38.3% of the drugs were prescribed from National Essential Medicine List (NEML) and STG respectively. The IRDP was 3.96 over 5 points. The average cost of drugs per prescription was 4.2 USD. The cost of drugs in the prescriptions written according to STG was lower compared to that in prescriptions not compliant with the STG (p < .001).Conclusions: TCAs are the most commonly prescribed antidepressants due to their affordability. The generic prescribing, medicines prescribed from the NEML and in compliance with the STG were less than the WHO standard. The rational drug use is suboptimal. Better prescribing habits, affordability and use of newer antidepressants should be encouraged by the hospital management.