Prescribing Safety Assessment (PSA) Practice Exam

What effect do p450 inducers have on drug metabolism?

1. They increase the drug levels of other drugs

2. They decrease drug levels

3. They inhibit the metabolism of drugs

4. They have no significant impact

The correct answer is: They increase the drug levels of other drugs

The correct answer refers to the role of cytochrome P450 (CYP450) inducers in pharmacology, which are substances that enhance the metabolic activity of liver enzymes responsible for drug metabolism. When these inducers are present, they increase the rate at which drugs are metabolized. This heightened metabolic activity typically leads to a decrease in the plasma levels of other co-administered drugs that are substrates of the same CYP450 enzymes, meaning that these drugs are broken down more quickly and may therefore have reduced therapeutic effects. This effect is significant because it can result in subtherapeutic levels of the affected drugs, potentially leading to treatment failure. Understanding the role of P450 inducers is crucial in clinical settings to avoid complications from drug interactions, ensuring that patients receive the appropriate dosages necessary for effective treatment. In this context, the assertion that P450 inducers increase the drug levels of other drugs is not accurate; rather, they are known to decrease these levels by increasing drug clearance through enhanced metabolic processes.