Rectal drug administration is useful for patients who are unable to take medications orally due to nausea, vomiting, or difficulty swallowing. This route of administration can reduce systemic side effects by delivering drugs directly to the rectum and lower colon. Rectal drug administration also bypasses first-pass metabolism in the liver.

Rectal drug administration can be messy and inconvenient to administer because it involves inserting suppositories or enemas into the rectum.

a. Rectal drug administration can have a rapid onset of action, but this is not a disadvantage.

c. The cost of rectal drug administration can vary depending on the medication used, but it is not necessarily more expensive than other routes of administration.

d. Rectal drug administration is non-invasive.

Acetaminophen is commonly administered rectally in the form of a suppository for the treatment of pain and fever. This route of administration allows for effective delivery of medication in patients who are unable to take medications orally.

b. Furosemide is commonly administered orally or intravenously, not rectally.

c. Metoprolol is commonly administered orally, not rectally.

d. Simvastatin is commonly administered orally, not rectally.

Rectal drug administration delivers drugs directly to the rectum and lower colon, allowing for high local drug concentrations and reducing systemic side effects.

a. This statement is false because rectal drug administration delivers drugs directly to the rectum and lower colon, not specifically to the liver.

b. This statement may be true or false depending on the specific medication and condition being treated. Rectal drug administration can have a rapid onset of action for some conditions but may have a slower onset of action compared to oral administration for others.

d. This statement is false because rectal drug administration is non-invasive.

Rectal pH, the presence of stool in the rectum and blood flow to the rectum can all affect absorption of rectally administered drugs. For example, some drugs may require an acidic environment for optimal absorption and may be affected by changes in rectal pH. The presence of stool in the rectum can also affect absorption by altering contact between the drug and mucous membranes. Blood flow to the rectum can affect absorption by altering the rate at which drugs are delivered to the absorption site.