The effect of various topical antibiotic and antibacterial agents on the middle and inner ear of the guinea-pig.

The topical application of antibiotics and anti-inflammatory agents is used to reduce inflammation of the middle ear mucosa and irradicate infection. Many of the antibiotic and anti-inflammatory preparations so used contain compounds known to be or are potentially ototoxic. Eighteen antibiotic, antibacterial, antifungal and anti-inflammatory compounds and four commonly used solvents were screened for the absence of ototoxicity and inflammation to the middle ear mucosa. All compounds were injected intra-tympanically and sensory hair cells loss recorded graphically. Inflammation of the middle ear mucosa was assessed macroscopically. Of the 18 compounds only three, penicillin, carbenicillin and nystatin were free of hair cell toxicity and inflammatory effects on the middle ear mucosa. Only one of the commonly used solvents was free of side effects.