University of Pennsylvania Medical Center Guidelines for Antibiotic Use
There is little information in the literature addressing chloramphenicol dosing and serum concentration monitoring in adults. Serum concentrations above 25 mcg/ml have been associated with an increased rate of bone marrow toxicity. Studies have not been done to show a correlation between trough levels and toxicity, and no studies to date have been able to show a correlation between levels and clinical efficacy and the development of resistance. The following guidelines are based on what is known about the dosing of chloramphenicol for patients with multi-drug resistant enterococcal infections including neutropenic patients.
Initial chloramphenicol dosing:
1. 40 - 50 mg/kg/day in 3 - 4 divided doses for patients with normal renal and hepatic function (**doses up to 100 mg/kg/day may be necessary in severe infections such as meningitis)
2. 30 - 35 mg/kg/day in 2 - 3 divided doses based on severity of hepatic and renal impairment
3. PHARMACOKINETICS CONSULT is recommended for all patients receiving chloramphenicol
Monitoring chloramphenicol:
1. Baseline CBC upon ordering chloramphenicol and then a minimum of 3 times per week. If counts begin to decrease, then CBC should be monitored more frequently.
2. Recommended trough levels are 5 -10 mcg/ml and peak levels between 15 - 20 mcg/ml. If patient relapses or appears to be failing therapy, then the dose can be increased to achieve peaks of 21 - 25 mcg/ml (**if dosing for higher levels, remember to closely monitor CBC for toxicity).