Haemophilus influenzae Infections

The clinical manifestations of Haemophilus influenzae infections and the growing problem of ampicillin-resistant strains are reviewed. Despite the fact that approximately 25 percent of H. influenzae are resistant to penicillin and ampicillin, oral aminopenicillins (ampicillin, amoxicillin, bacampicillin, and cyclacillin) are commonly used for the outpatient management of these infections. The characteristics of these drugs and the rationale for their use are discussed and compared with alternative approaches to therapy. This subject requires periodic review in consideration of the increasing prevalence of ampicillin and multiple antibiotic resistance among H. influenzae isolates.