Which tetracycline antibiotic is NOT contraindicated in a patient with kidney failure?

• A. Tetracycline
• B. Doxycycline
• C. Minocycline
• D. Demeclocycline

Answer: (B)

In kidney failure, how a drug is eliminated matters a lot. Doxycycline is not contraindicated because it is cleared mainly by the liver and biliary system, with only a small portion removed by the kidneys. This means it doesn’t tend to accumulate in renal impairment, so no dose adjustment is usually needed. The other tetracyclines rely more on renal excretion, so their levels can rise when kidney function is poor, increasing toxicity risk. Demeclocycline, in particular, has nephrotoxic potential and is avoided in kidney failure. So doxycycline stands out as the tetracycline you can use when kidney function is compromised.