<prompt> Selective decrease in IgA is seen with administration of:PhenytoinDiazepamClonazepamPhenobarbitone  <response>: Ans: A Phenytoin Ref: Goodman Gillmans The Pharmacological Basis of Therapeutics, 2011, 12th Edition, McGrow Hid, Burton LL, P 593Explanation:Phenytoin can cause lymphadenopathv similar to Hodgkins disease and malignant lymphoma. This is attributed to decrease in IgA production.Other Adverse Effects of PhenytoinNeurologicHorizontal gaze nystagmusSedationCerebellar ataxiaCerebellar atrophyOphthalmoparesisSeizuresHematologicMegaloblastic anemiaAgranulocytosisAplastic anemiaLeukopenia Thrombocytopenia.TeratogenicityPhenytoin is a known teratogen and causes fetal hydantoin syndromeThe syndrome consists of craniofacial anomalies broad nasal bridge, cleft lip and palate, microcephaly and a mild form of mental retardation average IQ71DermatologicHypertrichosisRashExfoliative dermatitisPruritisHirsutismCoarsening of facial featuresSJS and TENOthersGingival hypertrophy overgrowth of the gums can be decreased with folate supplementationInduction of reversible IgA deficiencyDrug-induced lupus.Hypocalcemia 