Tetracyclines, includingdoxycycline and minocycline, are broad-spectrum antibiotics used to treat bacterial infections. They have amajor drug-drug interaction with calcium-containing antacidsand other minerals.
Chelation Effect:Calcium binds to tetracycline, forminginsoluble complexesthat prevent the antibiotic from being absorbed in thegastrointestinal (GI) tract.
Reduced Efficacy:Because the drug cannot be absorbed, the antibiotic’s effectiveness is significantly reduced.
Similar Interactions:Magnesium, iron, and aluminum (found in many antacids, dairy products, and multivitamins) also reduce tetracycline absorption.
Take on an Empty Stomach(1 hour before or 2 hours after meals).
Avoid Dairy, Antacids, and Multivitaminsfor at least2 hours before and aftertaking tetracycline.
Drink with a Full Glass of Waterto prevent esophageal irritation.
B. Decongestants that contain pseudoephedrine.→ Incorrect. Pseudoephedrine does not interact with tetracycline.
C. Antitussives that contain dextromethorphan.→ Incorrect. Dextromethorphan does not affect tetracycline absorption.
D. Analgesics that contain acetaminophen.→ Incorrect. Acetaminophen does not bind to tetracycline or impact its absorption.
Lexicomp Drug Interaction Database – Tetracycline and Calcium Interactions.
FDA Drug Label for Tetracycline – Absorption and Drug Interaction Warnings.
Mosby’s Pharmacy Technician: Principles and Practice – Tetracycline Pharmacology.
PTCB PTCE Exam Content Outline – Drug Interactions and Contraindications.
Why Should Tetracycline Not Be Taken with Calcium-Containing Antacids?Patient Counseling for Tetracycline Use:Why the Other Answer Choices Are Incorrect:Pharmacy Technician References:
