In addition to bismuth and iron, tetracycline should not be taken with which of the following?

• A. Citrus
• B. Dairy
• C. Antacids
• D. Carbonated drinks

Answer: (B)

Tetracycline is an antibiotic that has specific interactions with certain substances that can affect its absorption and effectiveness. One of the known interactions is with calcium-rich foods, particularly dairy products. When tetracycline is taken with dairy, the calcium in these products binds to the antibiotic, forming insoluble complexes that decrease the drug's absorption in the gastrointestinal tract. This means that the therapeutic effectiveness of tetracycline can be significantly compromised, resulting in reduced efficacy in treating infections.

While other substances like antacids can also interact with tetracycline due to their metal content (such as magnesium or aluminum), dairy is particularly problematic due to its high calcium content. This property makes dairy products a clear substance that should not be consumed alongside tetracycline to ensure maximum absorption and effectiveness of the medication.