INVESTIGATION OF THE INFLUENCE OF ACETYLSALICYLIC-ACID ON THE STEADY-STATE OF LONG-TERM THERAPY WITH THEOPHYLLINE IN ELDERLY MALE-PATIENTS WITH NORMAL RENAL-FUNCTION

The risk inherent in the clinical control of patients with theophyllin e is widely recognized. Elderly patients may present an additional ris k because of altered pharmacokinetics and the use of concomitant medic ation. Acetylsalicylic acid has been proposed for primary and secondar y prevention of myocardial infarction and possible strokes. This inves tigation was undertaken to determine if concomitant administration of acetylsalicylic acid in elderly patients would alter steady state leve ls of theophylline. A population of smoking male patients older than 6 0 years of age under long-term control of chronic obstructive pulmonar y disease (COPD) with theophylline were evaluated for a baseline perio d of 3 days. Serum levels were measured at 6:00 AM and 6:00 PM, An ent eric-coated acetylsalicylic acid preparation, 650 mg by mouth, was add ed to the daily slow-release theophylline, 6:00 AM hour dose regimen f or 4 weeks. The serum levels of theophylline and salicylates were meas ured at 6:00 PM after dosing and at 6:00 AM the following day, at week ly intervals for 4 weeks. Urine specimens collected before administrat ion of medication at 6:00 AM were analyzed for salicylates to further confirm dosage compliance. All volunteers continued to be clinically c ontrolled throughout the treatment period, and no symptoms of either o verdose or underdose of either medication occurred. Plateau or trough theophylline serum levels did not change significantly during the sali cylate treatment period. Salicylate serum levels did show during treat ment self-induced metabolism. It is concluded that in elderly male pat ients, a daily concomitant therapeutic salicylate regimen does not alt er steady-state serum theophylline levels and therefore does not per s e necessitate the assay of theophylline blood levels in elderly patien ts.