Integrated Laboratory and Clinical Evaluation of Antidiabetic and Antihypertensive Medicines in Osun State, Nigeria: Linking Pharmaceutical Care, Biomarkers, and Drug Safety in Routine Care

Type 2 diabetes mellitus (T2DM) and hypertension commonly coexist and require lifelong pharmacotherapy. In routine care, outcomes may be undermined by variable medicine quality, suboptimal adherence, limited biomarker monitoring, and weak detection and reporting of adverse drug reactions (ADRs). This study evaluated the laboratory quality performance of commonly used antidiabetic and antihypertensive medicines circulating in Osun State, Nigeria, and examined real-world clinical outcomes, pharmaceutical care indicators, biomarkers, and drug safety among patients receiving these therapies. An integrated design with two coordinated streams was implemented. In the laboratory stream, antidiabetic and antihypertensive samples were obtained from facility pharmacies and private-sector outlets and assessed using compendial-style methods for product identification, assay (content), and dissolution performance. In the clinical stream, adults with diagnosed T2DM and/or hypertension receiving at least one antidiabetic and/or antihypertensive medicine were enrolled from selected outpatient facilities and followed over a defined period. A structured pharmacist-led pharmaceutical care workflow was embedded into dispensing and follow-up, including medication review, adherence support, counseling on correct use and safety, and systematic identification of medication-related problems. Clinical effectiveness was evaluated using blood pressure and glycemic indicators (HbA1c where available and fasting plasma glucose where applicable), alongside safety-relevant biomarkers such as renal function indices and electrolytes where feasible. Active safety surveillance was conducted through structured elicitation and documentation of suspected ADRs, with clinical escalation pathways for serious events. Where possible, patient-used products were linked to laboratory-tested samples using brand and batch identifiers to support exploratory integration analyses. Laboratory findings indicated high identity compliance with measurable noncompliance in assay and/or dissolution in a subset of samples, more frequently observed among products sourced from private-sector outlets than facility pharmacies. Clinically, adherence and key outcomes improved with pharmaceutical care, while ADR surveillance identified a meaningful burden of mostly mild-to-moderate reactions with a preventable component. These results support integrating risk-based post-market surveillance, pharmaceutical care, biomarker monitoring, and pharmacovigilance to improve effectiveness and safety of cardiometabolic therapy in Osun State.