Mitigating possible shortages: validating blood collection tubes for therapeutic drug monitoring

Abstract

Background: This study was conducted at a National Health Laboratory Service (NHLS) regional laboratory in response to possible shortages of blood collection tubes supplied by Becton Dickinson (BD).
Aim: The study aimed to evaluate four alternative tubes available in South Africa to seek one suitable for therapeutic and toxic drug monitoring (TDM).
Methods: After ethical approval, 50 healthy adult volunteers were recruited, and blood samples were drawn into BD and four candidate tubes. Calibrators of 13 drugs were spiked into the whole blood collected in BD serum separator (SS) tubes, the four candidate tubes, and recoveries were calculated. Drug levels were measured using a Beckman UniCel DxC 800 analyser and compared between BD and the other tubes. Criteria for clinical acceptability were used to evaluate the tubes’ suitability.
Results: The VACUCARE^® (EV) tube showed acceptable recoveries for all 13 drugs tested, while the VACUETTE^® (LG) tube had lower recovery than BD for gentamicin. The V-TUBE™ (VT) tube also showed lower recovery compared with BD for valproic acid, while the VACUTEST^® (KV) tube showed lower recoveries for valproic acid, amikacin, salicylate, and digoxin compared with BD.
Conclusion: Based on the criteria of clinical acceptability of the 13 drugs tested, the LG and EV tubes were the most suitable for therapeutic and toxic drug monitoring and can be considered alternatives to the BD tubes.