Effects of heat treatment on selected plasma therapeutic drug concentrations.

OBJECTIVE: We investigated the heat stability of six common therapeutic drugs routinely assayed in pharmacokinetic and clinical laboratories. DESIGN: Serum samples were spiked at three concentrations (subtherapeutic, therapeutic, and potentially toxic) with amikacin, gentamicin, tobramycin, phenytoin, theophylline, and phenobarbital. The samples were then heated at 56 degrees C and assayed by fluorescence polarization immunoassay at 15-minute intervals for one hour. SETTING: The study was conducted at a clinical research laboratory using standard laboratory methods. MAIN OUTCOME MEASURES: Drug concentrations of heated samples were compared with unheated controls using ANOVA to determine if degradation occurred over time with heating. RESULTS: Analysis of data revealed no degradation of any of the samples. CONCLUSIONS: Heat treatment of samples from high-risk individuals may be a mechanism to protect healthcare workers from exposure to the human immunodeficiency virus.