Lack of effect of tacrine administration on the anticoagulant activity of warfarin.
The effect of tacrine administration on prothrombin time was studied in 13 patients receiving prolonged warfarin therapy. After a 3-week baseline period and 5 days of placebo administration, patients received 20 mg tacrine four times daily for 5 days. Prothrombin times were determined during baseline, daily before the morning doses of placebo and tacrine, and 14 days after the last tacrine dose (closeout). Mean (+/- SD) prothrombin times were 16.2 +/- 2.8 seconds at baseline, 15.1 +/- 2.6 seconds during the placebo phase, 15.8 +/- 3.6 seconds during the tacrine phase, and 15.3 +/- 3.6 seconds at closeout, indicating that tacrine has no effect on the anticoagulant activity of warfarin. Alteration of warfarin dosage should not be required in patients receiving concurrent tacrine therapy.
Reece
P A
PA
Department of Clinical Pharmacology, Parke-Davis Pharmaceutical Research Division, Warner-Lambert Company, Ann Arbor, Michigan 48106-1047, USA.
Garnett
W R
WR
Rock
W L
WL
Taylor
J R
JR
Underwood
B
B
Sedman
A J
AJ
Rajagopalan
R
R
D000368:Aged; D000369:Aged, 80 and over; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011517:Prothrombin Time; D013619:Tacrine / Q000008:administration & dosage / Q000494:pharmacology*; D013997:Time Factors; D014859:Warfarin / Q000494:pharmacology*
D013619:Tacrine; D014859:Warfarin