Drug–Nutrient Interactions

Drug–nutrient interactions (DNIs) are on the increase in older adults due to the high prevalence of polypharmacy in the setting of comorbidity, presenting the opportunity for drug interactions with nutrients. There is a growing awareness of the problem. The impact and burden of DNIs in older adults include morbidity, hospitalizations, and mortality. DNIs increase or decrease the efficacy of medications and contribute to adverse drug events and involve numerous therapeutic classes. Risk factors contributing to DNIs, types of interactions, and consequences, using examples of commonly used medications and herbal preparations, and nutrient interactions are presented. Interactions involve pharmacokinetic and pharmacodynamic properties of medications, resulting in amplification or nullification of the drug or nutrient effect. Long-term medication adverse effects include nutrient depletion, typically of vitamins and minerals. Awareness of DNIs and streamlining proper drug selection offers opportunity to prevent adverse events, and consequent morbidity, mortality, and healthcare costs. Drug interactions with common fruits, fruit juices, and beverages such as grapefruit and grapefruit juice, and caffeine are discussed. Factors that limit understanding and provider efforts include time constraints, shorter hospital stays, inadequate understanding of the vast drug formularies and interactions, and inadequate efforts directed at medication reconciliation and diet history. Nutritionists, nurses, pharmacists, and physicians must utilize multidisciplinary efforts and a coordinated approach to benefit patients in preventing DNIs. Healthcare providers are expected to offer instructions to patients concerning proper medication intake in relation to food, choice of vehicle to take the drug, and the timing of administration with respect to meals.