Drug Interactions Guide
Drug interactions occur when one medication affects the activity of another. They can reduce effectiveness, increase side effects, or in severe cases cause life-threatening reactions.
Types of Drug Interactions
- Drug-drug interactions: Between two or more medications
- Drug-food interactions: Food affecting how a drug works
- Drug-supplement interactions: Herbal supplements like St. John's Wort
- Drug-disease interactions: A medication worsening an existing condition
Most Dangerous Drug Combinations
Warfarin + Aspirin or NSAIDs: Dramatically increases bleeding risk. MAOIs + SSRIs: Can cause fatal serotonin syndrome. Statins + Clarithromycin: Can cause severe muscle breakdown (rhabdomyolysis).
⚠️ Grapefruit juice inhibits liver enzymes that metabolize many medications. A single glass can cause dangerous drug level spikes that last 24–72 hours. Affected drugs include statins, some calcium channel blockers, and several HIV medications.
How to Prevent Dangerous Drug Interactions
Always tell your doctor and pharmacist about every medication, supplement, and herbal product you take. Use a free drug interaction checker before starting any new medication. Never stop taking prescribed medications without consulting your physician first.