Understanding Beverage Interactions with Medications

Interactions Between Beverages and Medications: A Guide for Patients and Physicians

Understanding how beverages interact with medications is crucial for patient safety. By informing patients about these interactions and sharing this knowledge with colleagues, we can mitigate the risk of adverse effects.

Grapefruit Juice
Citrus fruits contain furanocoumarins, which inhibit enzymes responsible for metabolizing drugs, such as cytochrome P450. Concurrent intake can decrease the effectiveness of certain drugs and slow the elimination of others, leading to increased toxicity. More than 85 interactions between grapefruit and medications are known, including statins, calcium channel blockers, PDE-5 inhibitors, warfarin, and others. Different drugs within the same class may experience varying effects due to slight differences in chemical structure, affecting metabolism mechanisms and enzyme groups involved.

Similar effects can be observed with apple, orange, and pomegranate juices, albeit less frequently.

Coffee, Tea, Energy Drinks
Energy drinks and some carbonated beverages contain caffeine, which has stimulating and diuretic effects. Combining them with ciprofloxacin or cimetidine can slow caffeine metabolism, leading to nervousness and insomnia. Other fluoroquinolones and H2 receptor blockers (ranitidine) may have less pronounced interactions with caffeine and could serve as alternatives to ciprofloxacin and cimetidine.

Tea, rich in tannins, interferes with the absorption of oral contraceptives and iron supplements. Conversely, tannins enhance the action of antidepressants.

Herbal Infusions and Decoctions
Biologically active components in herbal remedies can affect medication efficacy. Although interactions between drugs and plants are poorly understood, some notable ones include:

  • St. John’s Wort increases liver enzyme activity, leading to accelerated metabolism and excretion of oral contraceptives.
  • Ginkgo biloba combined with warfarin increases the risk of bleeding.
  • Ginseng may reduce the effectiveness of calcium channel blockers, chemotherapy drugs, and HIV medications.

Calcium and magnesium in milk form chelates with certain antibiotics, bisphosphonates, and omeprazole, reducing their absorption and efficacy. Additionally, milk protein can enhance the absorption of propranolol, leading to arterial hypotension.

Alcohol, a central nervous system depressant, can intensify dizziness, drowsiness, and respiratory depression when combined with certain medications. Combining ethanol-containing beverages with prednisolone or NSAIDs may result in gastric bleeding and ulcer disease. At least 536 drugs interact with ethanol, with 38 requiring special attention and caution.

To avoid adverse interactions, it is recommended to take all medications with water. This minimizes the influence of beverages on drug efficacy and reduces the risk of unwanted side effects.