Pharmacologic and pharmacokinetic factors in blood donation: A risk-based deferral framework proposal

The presence of residual medications in blood donors can pose a risk to transfusion recipients, especially when drugs remain in plasma at clinically relevant levels. Current deferral recommendations for medicated donors are often generalized and lack pharmacokinetic rigor. This study aims to propose a pharmacologically and pharmacokinetically informed framework for assessing donor eligibility based on drug characteristics.

A structured literature review was conducted to evaluate key pharmacokinetic variables affecting drug persistence in blood, including half-life (t_½), time to maximum plasma concentration (t_max), maximum plasma concentration (C_max), and elimination pathways. Medications were stratified into five risk categories according to their pharmacological profile, systemic exposure, and clinical implications. Corresponding deferral periods were assigned to each category. The framework also considers the type of blood component being donated (e.g., plasma-rich vs. cellular products).

Medications with long half-lives, genotoxic effects, or antiplatelet activity pose higher transfusion risks and require extended deferral periods. Conversely, drugs with minimal systemic absorption, low plasma bioavailability, or that serve as physiological replacements pose minimal risk and may not warrant deferral. The proposed model aligns deferral recommendations with drug clearance data and product-specific plasma exposure.

A pharmacokinetic approach to donor eligibility enhances transfusion safety and supports evidence-based deferral guidelines. Pharmacists and clinicians can collaborate to assess medication risk profiles and optimize donor selection. This model can reduce unnecessary deferrals and maintain blood supply integrity while protecting recipients.