Drug Utilization Review and Medication Adherence in a Nigerian Psychiatric Hospital

Abstract

Background: Drug utilization research facilitates the rational use of drugs and suggests measures to improve prescribing habits. Irrational use of drugs is a global problem affecting patient care. It results in increased mortality, morbidity, adverse drug events, and wastage of economic resources.The success of medication treatment is dependent on a patient’s adherence to the medication regimen and non-adherence amongst psychiatric patients is associated with poor clinical outcomes and high resource utilization.

Objectives: The objectives of this study were to evaluate the pattern of drug utilization and the level of patients’ adherence to psychotropic drugs in a Nigerian Psychiatric Hospital.

Methods: Based on the WHO core indicators of rational drug use, data was obtained retrospectively from a review of 5400 outpatient prescriptions from September 2007 to August 2012. Data evaluation was done using the WHO guideline for assessment of drug use in health facilities. Furthermore, Morisky’s scale, (an eight-item validated questionnaire) was employed to obtain information on adherence of patients to medications from two hundred (200) outpatients. The results were analyzed using the Statistical Package for the Social Sciences (SPSS).

Results: A total number of 5400 prescriptions were used in this study. The pattern of prescription in the facility revealed that an average of 2.88 drugs was prescribed per encounter, 94.38 % of the drugs were prescribed by their generic names, and 36.13% of the prescriptions had injection prescribed. The percentage of encounters with antibiotics prescribed was 2.6% while 99.4% of all the drugs encountered were prescribed from the essential drugs list. The drugs whose utilization accounted for about 90% of the entire drug use (DU90%) include Haloperidol, Amitriptyline, Benzhexol, Trifluoperazine, Chlorpromazine and Carbamazepine. Haloperidol was the most utilized drug in the setting with a DDD/ 1000 inhabitants /day of 5. In more than 70% of the prescriptions encountered, all the drugs prescribed were available in the hospital pharmacy. With respect to patient adherence, 55.5% of patients were classified as having low adherence, 36% with moderate adherence and 8.5% having high medication adherence level. Conclusion: The drug utilization review at the psychiatric hospital, Uselu found that polypharmacy was frequently practiced while haloperidol was the most utilized drug. About 70% of the prescribed drugs were available at the hospital pharmacy. Outpatients’ adherence to medications was very low while socio-demographic features of patients did not affect adherence.