Mesna is used in -

Ans. is 'a' i.e,, Hemorrhagic cystitiso Cyclophosphamide, an anticancer drug is the drug of choice for Wegener's granulomatosis.o Cyclophosphamide is a prodrug and is activated by hepatic biotransformation to aldophosphamide. One of its degradation products is acrolein that is responsible for hemorrhagic cystitis (its characteristic adverse effect). This adverse effect can be decreased by vigorous hydration and by the use of mercapto ethane sulfonic acid (mesna).o Cyclophosphamide may also result in cardiac dysfunction, pulmonary toxicity' and syndrome of inappropriate ADH secretion. Related drug ifosfamide is also implicated in causing hemorrhagic cystitis. Cyclophosphamide is a powerful vesicant.