The kinetics of the nootropic drug oxiracetam was studied in 6 elderly female patients (age range 69-96 years) in good physical condition. After a single oral dose (800 mg), serum oxiracetam levels reached a peak (25 +/- 6 micrograms/ml) within 1-3 h and declined thereafter with a half-life of 3 to 6 h. Eighty-four percent of the administered dose was recovered in urine as unchanged drug within 24 h. During a maintenance regimen (800 b.i.d. at 8 a.m. and 2 p.m.) for 7 days oxiracetam did not show any accumulation in serum, trough serum levels before the morning and afternoon doses being 4.6 +/- 2.3 and 17.0 +/- 8.2 micrograms/ml respectively on day 4 and 5.7 +/- 3.3 and 17.9 +/- 7.7 micrograms/ml respectively on day 7. Comparison with previous pharmacokinetic data obtained in young subjects suggests that the clearance of the drug is lower in the elderly, probably as a result of the physiological decrease in renal function in old age.