Designing a Pharmacokinetics-Guided Dosing Protocol for Vancomycin in Nigerian Critical Care Settings

Vancomycin is a critical antibiotic for severe Gram-positive infections, and its pharmacokinetics-guided individualised dosing is essential for achieving therapeutic efficacy while minimising nephrotoxicity. This study designed a clinical pharmacokinetics-based dosing protocol for vancomycin use in critical care settings at teaching hospitals in South South Nigeria, using Bayelsa and Rivers States as development sites. A protocol development methodology encompassing retrospective vancomycin use audit, population pharmacokinetic literature synthesis, and clinical expert consensus was adopted. Audit of 90 vancomycin-treated patients in ICU and high dependency units across three hospitals revealed vancomycin trough concentrations within the recommended range of 15 to 20 mg/L in only 33.3 percent of patients. Supratherapeutic levels were associated with significantly higher rates of nephrotoxicity (p < 0.01). Initial dosing was empiric without pharmacokinetic calculation in 78.9 percent of cases. The designed protocol incorporates initial dose calculation using patient weight, renal function, and infection severity; therapeutic drug monitoring schedule based on dosing frequency; Bayesian dose adjustment algorithm adapted for Nigerian population pharmacokinetic data; nephrotoxicity monitoring triggers; and de-escalation criteria. Clinical pharmacy implementation requirements and documentation standards are included. Expert review by 12 clinical pharmacists, infectious disease physicians, and intensivists validated the protocol. The study recommends piloting the protocol at two teaching hospital ICUs in the South South zone, with formal pharmacokinetic outcome evaluation. Keywords: vancomycin, pharmacokinetics-guided dosing, critical care, South South Nigeria, therapeutic drug monitoring