Evaluation of Clinical Pharmacist Roles in Intensive Care Units: Evidence from University Teaching Hospitals in South West Nigeria

Background: Clinical pharmacists embedded in intensive care units (ICUs) have demonstrated substantial benefits in reducing medication errors, adverse drug events, and mortality in international studies. In Nigeria, the formalisation of clinical pharmacy in ICU settings is still evolving. This study evaluated the scope and impact of clinical pharmacist roles in ICUs at university teaching hospitals in South West Nigeria. Methods: A multi-site cross-sectional study was conducted at the ICUs of three university teaching hospitals in Lagos, Ibadan, and Ile-Ife. Structured observation, pharmacist interviews (n = 35), and retrospective review of 300 ICU medication records were employed. Role domains assessed included medication reconciliation, drug therapy monitoring, dose optimisation, and ADR identification. Results: Clinical pharmacists were formally assigned to ICUs in two of three hospitals, but daily rounding was practised in only one facility. Medication reconciliation was performed in 61 percent of admitted patients where pharmacists were present. Pharmacist-detected medication errors totalled 112 across the review period, with 28 percent rated clinically significant. Conclusion: Clinical pharmacists add measurable value to ICU care in South West Nigeria, but structural integration remains incomplete. Clear role definitions, multidisciplinary team training, and staffing policies are required to maximise ICU pharmacist impact. Keywords: clinical pharmacist, intensive care unit, medication errors, South West Nigeria, pharmaceutical care