Antibiotic Do's and Don'ts — Interactions, Resistance & Safe Use
Antibiotics must be taken correctly to remain effective and prevent antibiotic resistance. Learn which foods, drugs, and habits to avoid while on a course of antibiotics.
Foods to Avoid on Antibiotics
①Dairy products: Calcium in milk and yoghurt binds to tetracycline-class antibiotics (e.g., doxycycline) and reduces absorption by up to 80%. Space dairy by at least 2 hours. ②Grapefruit: Can raise blood levels of certain antibiotics (erythromycin, clarithromycin), increasing side-effect risk. ③Alcohol: Weakens the immune response and delays recovery. With metronidazole or tinidazole, alcohol causes a severe reaction — flushing, nausea, rapid heartbeat. Avoid alcohol completely with these drugs.
Drug Interactions
①Antacids, iron supplements, calcium supplements: Bind to quinolone (ciprofloxacin) and tetracycline antibiotics, blocking absorption. Take the antibiotic at least 2 hours before these supplements. ②Warfarin: Many antibiotics alter warfarin metabolism, raising the risk of bleeding. ③Oral contraceptives: Some antibiotics may reduce contraceptive effectiveness (evidence is debated, but extra precautions are reasonable). ④Other antibiotics: Never combine two antibiotic courses without a doctor's instruction.
Antibiotic Resistance Prevention
Always complete the full prescribed course, even if you feel better after a few days. Stopping early leaves surviving bacteria that may develop resistance. Never self-medicate with leftover antibiotics — antibiotics do not work against viruses (colds, flu). Antibiotic resistance is a global health emergency; every unnecessary dose contributes to it.
Taking Probiotics Alongside Antibiotics
Antibiotics kill beneficial gut bacteria along with the infection-causing ones, which can lead to diarrhoea and digestive upset. Taking a probiotic supplement (e.g., Lactobacillus or Saccharomyces boulardii) during antibiotic treatment can reduce these side effects. Space the probiotic and antibiotic by at least 2 hours so the antibiotic doesn't kill the probiotic strains. Continue probiotics for 1–2 weeks after finishing the course to help restore gut balance.