No Effect of Influenza Vaccination on Theophylline Pharmacokinetics as Studied by Ultraviolet Spectrophotometry, HPLC, and EMIT Assay Methods

Abstract
The effect of influenza vaccination on steady-state pharmacokinetics of theophylline was studied in six healthy young adults by comparing pharmacokinetic parameters found on days 4 and 5 during a 5-day course of theophylline alone with those obtained after influenza vaccination on day 4 of a second study phase. Theophylline plasma concentrations were measured by means of high-pressure liquid chromatography (HPLC) analysis and, in part, with a manual ultraviolet spectrophotometric method and with an EMIT assay. On the fourth and fifth days of each of the two periods of drug administration, theophylline plasma concentration-time curves were evaluated, and the following pharmacokinetic parameters were compared: trough plasma concentration (cmin), peak plasma concentration (cmax), time to peak (tmax), and the area under the curve during a dosing interval (AUC). None of these pharmacokinetic parameters of theophylline before and after vaccination were found to be significantly different with any of the analytical methods.