Clinical pharmacokinetics of theophylline and levels of alpha 1-acid glycoprotein in smokeless tobacco users.

Elimination half-life and apparent volume of distribution of theophylline were determined in ten healthy volunteers who used smokeless tobacco (snuff or chewing tobacco) regularly but did not smoke cigarettes. Serum concentrations of the acute phase reactant alpha 1-acid glycoprotein (AAG) were also measured. The elimination half-life of theophylline was 9.32 +/- 3.40 hours (mean +/- standard deviation), the apparent volume of distribution was 0.45 +/- 0.03 L/kg, and AAG concentrations were 63.8 +/- 15.76 mg/dL. All these values are comparable to values reported for nonsmokers. These results suggest that nonsmoking users of ST should be considered to be tobacco nonusers for purposes of planning theophylline dosing and monitoring strategies.