Question 1

In which way can hepatic enzymes be altered by drug metabolism?&#10;A) Can cause enhancement or inhibition of metabolism&#10;B) Can interact with the external environment&#10;C) Are only altered in conjunction with food&#10;D) Are only considered with regard to synergistic effects between drugs

Accepted Answer

Hepatic enzymes can be altered by drug metabolism, leading to enhancement or inhibition of metabolism. This can affect the pharmacokinetics of drugs and potentially impact their efficacy and toxicity. External environment, food, and synergistic effects between drugs can all have additional influences on drug metabolism, but they are not the primary way hepatic enzymes are altered.

Question 2

A common drug-food interaction is between grapefruit juice and:&#10;A) aspirin.&#10;B) paracetamol.&#10;C) felodipine.&#10;D) ibuprofen.

Accepted Answer

Grapefruit juice can increase the absorption of felodipine, a calcium channel blocker used to treat hypertension, leading to higher levels of the drug in the bloodstream and potentially causing side effects such as low blood pressure and irregular heart rhythm. It is important to avoid grapefruit juice or limit its consumption while taking felodipine. There is little evidence of significant interactions between grapefruit juice and aspirin, paracetamol or ibuprofen.

Question 3

When suxamethonium and thiopentone are mixed in the same syringe,the drug-drug interaction that results is:&#10;A) summation.&#10;B) chemical drug incompatibility.&#10;C) potentiation.&#10;D) augmentation.

Accepted Answer

Suxamethonium and thiopentone are chemically incompatible and can form a precipitate when mixed in the same syringe. This can lead to blockage of the injection site, making it difficult or impossible to administer the drugs. It is recommended to administer these drugs separately and through different injection sites.

Question 4

The drug interactions that occur with cimetidine are usually due to:&#10;A) enzyme inhibition.&#10;B) enzyme induction.&#10;C) protein binding.&#10;D) summation.

Accepted Answer

Cimetidine is known to inhibit certain enzymes, such as cytochrome P450 enzymes, which can lead to drug interactions. This results in decreased metabolism of other drugs, leading to higher concentrations and potentially toxic effects.

Deck 15: Drug Interactions