The effects of captopril on serum digoxin levels in patients with severe congestive heart failure.
The effects of captopril on serum digoxin concentrations were studied in 8 patients with severe (NYHA Class IV) congestive heart failure. Serum digoxin concentrations were determined before and after the administration of captopril for 1 week in patients on chronic digoxin therapy. Each patient who was taking 0.25 mg of digoxin PO q.d., was administered 12.5 mg of captopril PO t.i.d. for 7 days. The peak serum concentration of digoxin (Cmax) before and after (on Days 0 and 7) captopril administration was 1.7+/-0.2 ng/ml and 2.7+/-0.2 ng/ml, the time to peak (tmax) was 2.4+/-0.5 h and 1.3+/-0.2 h, and the area under the 24-hour digoxin concentration-time curve (AUC0-24h) was 30.0+/-1.5 ng x h/ml and 41.7+/-3.4 ng x h/ml, respectively. While captopril caused a significant increase in peak serum concentration and the area under the digoxin concentration-time curve, it decreased the time to digoxin peak (p = 0.01, p = 0.04, p = 0.01, respectively). No patient developed evidence of digoxin toxicity. Concomitant administration of captopril with digoxin increases serum digoxin concentration in patients with severe congestive heart failure.
Kirimli
O
O
Department of Cardiology, Dokuz Eylul University School of Medicine, Izmir, Turkey.
Kalkan
S
S
Guneri
S
S
Tuncok
Y
Y
Akdeniz
B
B
Ozdamar
M
M
Guven
H
H
D000284:Administration, Oral; D000368:Aged; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D002216:Captopril / Q000008:administration & dosage / Q000494:pharmacology*; D002316:Cardiotonic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D004077:Digoxin / Q000493:pharmacokinetics*; D004334:Drug Administration Schedule; D004347:Drug Interactions; D005260:Female; D006333:Heart Failure / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged
D000806:Angiotensin-Converting Enzyme Inhibitors; D002316:Cardiotonic Agents; D004077:Digoxin; D002216:Captopril