A patient on phenytoin therapy develops depression, for which he was prescribed tricyclic anti-depressants. He now complains of lassitude and his Hb reading is 8 gm/dl, the next step in the management of this patient is:: (A) Chest X ray, (B) MCV should be estimated, (C) GGT should be estimated, (D) None of the above
Answer is B. Ans. (B) MCV should be estimated(Ref: KD T 8/e p441)Phenytoin can induce folate deficient megaloblastic anemia that can be diagnozed by measuring MCV.