Interactions of oral antibiotics and common chronic medications.

Geriatric patients often require precise dose titration of certain drugs for effective, non-toxic treatment of chronic disease. When short-term antibiotic therapy is required, an oral antibiotic that would minimally disrupt a finely-tuned chronic drug regimen would be most appropriate. Chronic medication-antibiotic interactions are potentially more common with the use of erythromycin, tetracyclines, and sulfonamides. Clinicians should use care, and monitor for drug interactions when these agents are combined with chronically used drugs such as theophylline, warfarin, or carbamazepine.