Oxandrolone appears to offer less hepatic stress than other c-17 alpha alkylated steroids. The manufacturer identifies oxandrolone as a steroid that is not extensively metabolized by the liver like other 17-alpha alkylated orals, which may be a factor in its reduced hepatotoxicity. This is evidenced by the fact that more than a third of the compound is still intact when excreted in the urine. 405 Another study comparing the effects of oxandrolone to other alkylated agents including methyltestosterone, norethandrolone, fluoxymesterone, and methandriol demonstrated that oxandrolone causes the lowest sulfobromophthalein (BSP; a marker of liver stress) retention of the agents tested. 406 20 mg of oxandrolone produced 72% less BSP retention than an equal dosage of fluoxymesterone,which is a considerable difference being that they are both 17-alpha alkylated.
Torsemide is administered orally and intravenously. It is metabolized by the hepatic cytochrome P450 enzyme system and is a substrate for CYP2C9. In humans, three metabolites, one of which is active, are produced. The active metabolite does not contribute significantly to clinical activity. In normal adults, about 80% is cleared through hepatic metabolism and 20% is cleared in the urine as unchanged drug. In healthy adults, the elimination half-life is about hours.
Affected cytochrome P450 isoenzymes and drug transporters: CYP2C9
Torsemide is a substrate for CYP2C9. Theoretically, metabolism may be affected by drugs that are inhibitors of inducers of CYP2C9.