Purpose of the studyThe impact of clinical pharmacy (CP) services on primary healthcare (PH) is less well studied in resource-limited countries. We aimed to evaluate the effect of selected CP services on medication safety and prescription cost at a PH setting in Sri Lanka.Study designPatients attending a PH medical clinic with medications prescribed at the same visit were selected using systematic random sampling. A medication history was obtained and medications were reconciled and reviewed using four standard references. Drug-related problems (DRPs) were identified and categorised, and severities were assessed using the National Coordinating Council Medication Error Reporting and Prevention Index. Acceptance of DRPs by prescribers was assessed. Prescription cost reduction due to CP interventions was assessed using Wilcoxon signed-rank test at 5% significance.ResultsAmong 150 patients approached, 51 were recruited. Nearly half (58.8%) reported financial difficulties in purchasing medications. DRPs identified were 86. Of them, 13.9% (12 of 86) DRPs were identified when taking a medication history (administration errors (7 of 12); self-prescribing errors (5 of 12)), 2.3% (2 of 86) during reconciliation, and 83.7% (72 of 86) during medication reviewing (wrong indication (18 of 72), wrong strength (14 of 72), wrong frequency (19 of 72), wrong route of administration (2 of 72), duplication (3 of 72), other (16 of 72)). Most DRPs (55.8%) reached the patient, but did not cause harm. Prescribers accepted 65.8% (56 of 86) DRPs identified by researchers. The individual prescription cost reduced significantly due to CP interventions (p<0.001).ConclusionsImplementing CP services could potentially improve medication safety at a PH level even in resource-limited settings. Prescription cost could be significantly reduced for patients with financial difficulties in consultation with prescribers.