H. influenzae meningitis treated with ampicillin or chloramphenicol, and subsequent hearing loss.

Sensori-neural hearing loss after H. influenzae meningitis in children has been reported to occur more frequently after treatment with ampicillin than with chloramphenicol. In the present survey, hearing was assessed clinically and, in most cases, audiometrically in 47 children seen after H. influenzae meningitis. Three children were found to have some sensori-neural hearing loss. In no case was this severe or suspected prior to examination. One was among 27 children treated with ampicillin; one was among eight treated with ampicillin and chloramphenicol; and one was treated with chloramphenicol and streptomycin. Most of the children received ampicillin in a dose of 250mg/kg/day or less, but the two who were treated with ampicillin and developed hearing loss were among five children who received higher doses, suggesting that ampicillin may be ototoxic when given in very high doses.