What is a precaution that should be taken when administering saquinavir?

When administering saquinavir, the key precaution is to avoid grapefruit and pomegranate juice. This is important because these juices can significantly affect the metabolism of saquinavir due to their impact on the cytochrome P450 enzyme system, particularly CYP3A4. Saquinavir is extensively metabolized by this enzyme, and inhibitors like those found in grapefruit and pomegranate juice can lead to increased plasma concentrations of the drug. This could heighten the risk of side effects or toxicity.

It is also vital to understand that while saquinavir should be taken with food to enhance absorption, not all foods are appropriate. High-fat meals are actually recommended to increase its bioavailability, but that is specific to certain drug absorption characteristics. The timing of administration, whether in the evening or during the day, does not hold the same level of clinical significance in relation to drug metabolism as the interaction with grapefruit and pomegranate juice does. Thus, avoiding these juices is crucial for ensuring safe and effective use of saquinavir.