The theophylline effervescent tablet (Euphyllin quick 200) provides a new acute medication for the treatment of pulmonary obstructive lung diseases. Its pharmacokinetics were determined in 12 healthy male volunteers and compared in a single-dose crossover study to those after administration of an oral solution (Euphyllin 200 ampoule). Based on the primary pharmacokinetic characteristics for rate and extent of absorption, Cmax and AUC, both formulations were bioequivalent.