Chloramphenicol: recent developments and clinical indications.

Recent developments (including more accurate assays) that have led to revised recommendations for route of administration, dosage, and indications for chloramphenicol are reviewed. Chloramphenicol is most bioavailable by the oral route; doses of 75 mg/kg/day provide adequate therapeutic concentrations for most clinical indications. Serum concentrations of the drug should be monitored to ensure adequate therapeutic concentrations and to avoid toxicity. This is particularly important in newborns, in patients with liver dysfunction, and in those receiving concomitant drugs that may influence free chloramphenicol concentrations. The indications for chloramphenicol therapy evaluated are: Haemophilus influenzae infections, anaerobic infections, salmonellosis, Rocky Mountain spotted fever, and eye infections. Chloramphenicol is useful in the treatment of invasive Haemophilus influenzae infections resistant to ampicillin, in selected anaerobic and ocular infections, and for rickettsioses in patients under the age of eight years. Because the rare but life-threatening complication of chloramphenicol (aplastic anemia) persists, indications for the drug's clinical use are narrowing once again with the advent of third-generation cephalosporins highly active against gram-negative bacilli including ampicillin-resistant H. influenzae. Similarly, metronidazole or clindamycin may be preferred for some anaerobic infections.