All are true about warfarin, except.
High-Yield Explanation
Ans. (D) Its dose is increased in liver disease(Ref: Katzung 11/e p595-596)Warfarin is an oral anticoagulant that acts by inhibiting the g- carboxylation of glutamate residues in vitamin-K dependent clotting factors (II, VII, IX and X).It has a long half life (t1/2 = 36 hours)It readily crosses the placenta. If given during pregnancy, it can result in 'Contradi syndrome' in the fetus.Liver disease reduces the synthesis of clotting factors, thus increases the effect of warfarin. The dose of this drug therefore, needs to be reduced in liver disease.