<prompt> Gynaecomastia may be associated with administration of-RanitidineCimetidineTerfenadineOmeprazole  <response>: Ans. is b i.e., Cimetidine Cimetidine but not other H2blockers o Has anti-androgenic action by displacing DHT from receptor o Increases plasma prolactin levels -- Galactorrhea in female o Inhibits degradation of Estradiol by liver. Therefore it cause gyaenecomastia, loss of libido, impotence temporary decrease in sperm count. Other adverse effects of cimetidine o CNS effects -- confusional state Delirium, restlessness, convulsions, coma, headache, dizziness, hallucination. o Bowel upset, rashes, dry mouth. o Bolus i.v. injection can cause histamine release -- arrhythmias and cardiac arrest. o Transient elevation of plasma aminotransferases. o Cimetidine inhibits several cytochrome P-450 isoenzymes -- inhibits metabolism of many drugs. 