Which of the following factors can affect the absorption of orally administered drugs?

First-pass metabolism occurs in the liver after a drug has been absorbed into the bloodstream from the gastrointestinal tract. It can reduce the bioavailability of a drug by metabolizing it before it reaches systemic circulation. First-pass metabolism does not occur with intravenous drug administration because drugs are injected directly into the bloodstream, bypassing the liver. Sublingual drug administration can also bypass first-pass metabolism because drugs are absorbed directly into the bloodstream through the mucous membranes under the tongue.

a. This statement is true, but it is not the best answer because it does not fully explain how first-pass metabolism can be bypassed.

b. This statement is false because first-pass metabolism can reduce, not increase, the bioavailability of a drug.

c. This statement is false because first-pass metabolism does not occur with intravenous drug administration.

Oral drug administration has a slower onset of action compared to other routes such as intravenous or intramuscular administration. This is because orally administered drugs must first pass through the gastrointestinal tract and be absorbed into the bloodstream before they can exert their effects.

a. Convenience and ease of use are advantages of oral drug administration, not disadvantages.

c. Being less expensive than other routes is an advantage of oral drug administration, not a disadvantage.

d. Being non-invasive is an advantage of oral drug administration, not a disadvantage.