title: Lack of effect of tacrine administration on the anticoagulant activity of warfarin.
abstract: 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.
authors.affiliation: Department of Clinical Pharmacology, Parke-Davis Pharmaceutical Research Division, Warner-Lambert Company, Ann Arbor, Michigan 48106-1047, USA.
authors.forename: P A
authors.initials: PA
authors.lastname: Reece
authors.forename: W R
authors.initials: WR
authors.lastname: Garnett
authors.forename: W L
authors.initials: WL
authors.lastname: Rock
authors.forename: J R
authors.initials: JR
authors.lastname: Taylor
authors.forename: B
authors.initials: B
authors.lastname: Underwood
authors.forename: A J
authors.initials: AJ
authors.lastname: Sedman
authors.forename: R
authors.initials: R
authors.lastname: Rajagopalan
mesh_terms: 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*
chemical_list: D013619:Tacrine; D014859:Warfarin