Which route avoids first-pass metabolism?

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Multiple Choice

Which route avoids first-pass metabolism?

First-pass metabolism happens when a drug is absorbed from the gut and then travels through the liver before reaching systemic circulation, which can significantly reduce the amount of active drug available. Delivering a drug by intravenous injection puts it directly into the bloodstream, so it bypasses the gut and hepatic portal system entirely. Because the drug doesn’t pass through the liver on its way to systemic circulation, it avoids first-pass metabolism altogether. Other routes can bypass first-pass only by delivering the drug straight to systemic circulation through mucous membranes or the skin (sublingual or transdermal), or, in oral form, do pass through the liver first via the portal vein, where significant metabolism can occur.

First-pass metabolism happens when a drug is absorbed from the gut and then travels through the liver before reaching systemic circulation, which can significantly reduce the amount of active drug available. Delivering a drug by intravenous injection puts it directly into the bloodstream, so it bypasses the gut and hepatic portal system entirely. Because the drug doesn’t pass through the liver on its way to systemic circulation, it avoids first-pass metabolism altogether. Other routes can bypass first-pass only by delivering the drug straight to systemic circulation through mucous membranes or the skin (sublingual or transdermal), or, in oral form, do pass through the liver first via the portal vein, where significant metabolism can occur.

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