Pharmacokinetics: Drug–Food and Drug–Viral Interactions

Drug interactions occur when a substance alters a drug's pharmacokinetics or pharmacodynamics, impacting its safety and efficacy.

Drug–food interactions affect drug pharmacokinetics. For example, grapefruit juice inhibits CYP3A4, a key metabolic enzyme. This can slow drug breakdown, leading to increased drug concentrations and a higher risk of toxicity.

Another example is the altered clearance of theophylline —a bronchodilator— when consumed with high-protein or charcoal-broiled foods.

Drug–viral interactions can also seriously impact drug efficacy and patient safety. However, the exact mechanism of such interactions is poorly understood.

For instance, aspirin use in children exposed to influenza B or varicella zoster infections can trigger Reye’s syndrome, leading to severe liver dysfunction and brain swelling.

Recognizing drug–food and drug–viral interactions is crucial for optimizing treatment outcomes and minimizing risks. Proper medication management is essential, particularly given the variation in dietary habits and viral infections across different patient populations.