Which of the following statements about oral anticoagulants is FALSE?: (A) They interfere with an early step in the synthesis of clotting factors, (B) Irrespective of the dose administered, their anticoagulant effect has a latency of onset of 1-3 days, (C) Their dose is adjusted by repeated measurement of prothrombin time, (D) They are contraindicated during pregnancy
Answer is A. (Ref: KDT 6/e p600, 601) Oral anticoagulants inhibit the activation of factor II, VII, IX and X. these do not affect the synthesis of these factors.