Stomach pH, food in the stomach, and blood flow to the gastrointestinal tract can all affect the absorption of orally administered drugs. For example, some drugs require an acidic environment for optimal absorption and may be affected by changes in stomach pH.

Food in the stomach can delay gastric emptying and slow down drug absorption.

Blood flow to the gastrointestinal tract can affect drug absorption by altering the rate at which drugs are delivered to the absorption site.

a. Stomach pH alone can affect drug absorption, but it is not the only factor.

b. Food in the stomach alone can affect drug absorption, but it is not the only factor.

c. Blood flow to the gastrointestinal tract alone can affect drug absorption, but it is not the only factor.

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.

Enteric-coated tablets should not be crushed before administration because the coating is designed to protect the drug from being destroyed by stomach acid or to prevent the drug from irritating the stomach lining. Crushing enteric-coated tablets can alter their effectiveness and safety.

b. Immediate-release tablets can be crushed before administration if necessary.

c. Chewable tablets are designed to be chewed before swallowing and do not need to be crushed.

d. Sublingual tablets are designed to be dissolved under the tongue and do not need to be crushed.

Oral drug administration is convenient and easy to use because it does not require any special equipment or training and can be self-administered by patients.

a. Oral drug administration does not have a rapid onset of action compared to other routes such as intravenous or intramuscular administration.

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

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

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.