Which antibiotic combination is identified as potentially inappropriate for older adults?

• A. Amoxicillin-clavulanate
• B. Sulfamethoxazole-trimethoprim
• C. Azithromycin
• D. Doxycycline

Answer: (B)

Beers Criteria highlights medications that pose higher risks to older adults. The combination of sulfamethoxazole and trimethoprim is identified as potentially inappropriate because trimethoprim can cause potassium retention and hyponatremia, leading to dangerous electrolyte disturbances in the elderly, especially when kidney function is reduced or when taken with other drugs that raise potassium (like ACE inhibitors, ARBs, or potassium-sparing diuretics). It also carries a higher risk of kidney function impact and can interact with anticoagulants such as warfarin, increasing bleeding risk. These safety concerns are particularly impactful in older adults, making this antibiotic combination the one flagged as potentially inappropriate. The other antibiotics listed do not carry the same broad Beers Criteria designation for older adults in this context.