<prompt> 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 8gmdl, the next step in the management of this patient is:Chest X rayMCV should be estimatedGGT should be estimatedNone of the above  <response>: phenytoin can induce folate deficient megaloblastic anemia that can be diagnozed by measuring MCV. REF: KD TRIPATHI 8TH ED. 