RESUMEN
Background - Regular medication reviews will reduce the occurrence of Drug Therapy Problems (DTPs). This study set out to identify, document DTPs and evaluate the impact of pharmacists´ interventions in selected health facilities. Methods - The study was carried out simultaneously at two tertiary and two secondary hospitals in Ogun States. Pharmacists were trained to document all identified DTPs in prescriptions and impacts of pharmacists' interventions for six months using the documentation form, PCNE V5.01. Data was analyzed and presented as frequencies with test of significance of main parameters. Results One hundred and four (104) DTPs were reported in all the health facilities but with no significant difference in occurrence at the two hospital levels. Commonly occurring DTPs were drug choice problems (35.6%), dosing problems (33.9%), adverse drug reaction (22.8%), drug use problems (4.23%) and drug interactions (1.69%). Most proposed interventions (77.0%) were approved by prescribers with (77.2%) resolution of DTPs in tertiary hospitals. Conclusion- There was no significant difference in occurrence of DTPs in the hospitals but there was higher incidence of non-allergic ADR, contraindication, duration of drug use and duplication of drugs at the secondary level. Acceptance rate of proposed interventions by physicians was high (77.2%) confirming that pharmacists' intervention in rational pharmacotherapy is valuable