The clinical pharmacology of milk-drug interactions: from pharmacokinetic principles to recent therapeutic recommendations

Milk consumption can significantly alter the pharmacokinetic and pharmacodynamic properties of drugs, impacting their therapeutic efficacy and safety. These interactions primarily affect orally administered medications through several key mechanisms. This review aims to systematically summarize the pharmacokinetic and pharmacodynamic mechanisms of milk-drug interactions, analyze their clinical implications across diverse populations, and provide practical recommendations to optimize therapeutic efficacy and safety. A major factor is milk's high calcium content, which can chelate with drugs like tetracyclines and fluoroquinolones, forming insoluble complexes that may reduce drug bioavailability by as much as 50–60%. Furthermore, milk proteins such as casein can bind to medications, altering their absorption in the gastrointestinal tract. The fat content in milk plays a dual role, enhancing the absorption of lipophilic drugs like griseofulvin while potentially delaying the absorption of hydrophilic drugs. Milk also acts as a buffer, raising gastric pH and thereby impairing the dissolution of acid-dependent drugs. While most interactions are pharmacokinetic, some pharmacodynamic effects are notable, such as the risk of a hypertensive crisis when patients on monoamine oxidase inhibitors (MAOIs) consume tyramine-rich aged cheeses. The clinical implications are significant, especially for vulnerable populations like children and the elderly who frequently consume milk and take medications. To avoid therapeutic failure or toxicity, healthcare providers should offer personalized dietary advice. A common recommendation is to separate drug administration from milk consumption by at least one to two hours to ensure optimal medication effectiveness and safety.