Chloramphenicol, a broad – spectrum antibiotic , is bacteriostatic. However , it may be bactericidal in high concentrations or when used against highly susceptible organisms. Chloramphenicol , which is lipid soluble , diffuses through the bacterial cell membrane and reversibly binds to the 50 S subunit of bacterial ribosomes where transfer of amino acids to growing peptide chains is prevented (perhaps by suppression of peptidyl transferase activity ) , thus inhibiting peptide bond formation and subsequent protein synthesis.

Treatment of brain abscess caused by B. fragilis or other susceptible organisms ; Treatment of ehrlichiosis ; Treatment of meningitis caused by H. influenzae , S. pneumoniae , and N. meningitidis; Treatment of paratyphoid fever caused by S. paratyphi A ; Treatment of Q fever ; Treatment of Rocky Mountain spotted fever ; Acute treatment of typhoid fever only caused by S. typhi ; Treatment of typhus infections. Chloramphenicol should be reversed for serious infections in which less toxic antibacterials are ineffective or contraindicated. Chloramphenicol is not indicated in the routine treatment of typhoid carrier states ; in the treatment of trivial infections , colds , influenza , or throat infection; or in the prophylaxis of infections.

a- Those indicating possible fatal , irreversible bone marrow depression , leading to aplastic anemia , and the need for immediate medical attention if they occur weeks or months after medication is discontinued : pale skin ; Sore throat and fever ; Unusual bleeding or bruising ; Unusual tiredness or weekness
b- Other side effects : Gray syndrome (abdominal distension , blue – gray skin color , low body temperature , uneven breathing , unresponsiveness, cardiovascular collapse ) in neonates only ; Skin rash ; Confusion ; Delirium ; Headache ; Depression ; Optic neuritis ; Peripheral neuritis ; Diarrhea ; Nausea ; Vomiting ; Stomatitis ; Anaphylaxis

Hypersensitivity to chloramphenicol or any component of the formulation.

Risk – benefit should be considered when the following medical problems exist : bone marrow depression , hepatic and renal function impairment , patients who have had previous cytotoxic drug therapy or radiation therapy . Use with care in patients with glucose 6 – phosphate dehydrogenase deficiency.

Chronic preoperative or perioperative use of chloramphenicol may decrease the plasma clearance and prolong the duration of action of alfentanil. Concurrent use with chloramphenicol may increase the bone marrow – depressant effects of hydantion , blood dyscrasia – causing medications, other bone marrow depressants and radiation therapy ; dosage reduction may be required . Concurrent use of chloramphenicol with tolbutamide and chlorpropamide may enhance their hypoglycemic effect ; dosage adjustments may be necessary . Glipizide and glyburide may not be affected as much as the other oral antidiabetic agents ; however , caution with concurrent use is recommended . Concurrent long – term use of chloramphenicol may result in reduced contraceptive reliability of oral estrogen – containing contraceptives and increased incidence of breakthrough bleeding . Clindamycin , erythromycin or lincomycin may be displaced from or prevented from binding to 50 S subunits of bacterial ribosomes by chloramphenicol , thus antagonizing the effects of erythromycins and lincomycins ; concurrent use is not recommended . Concurrent use of chloramphenicol with hepatic microsomal enzyme inducing drugs, including phenobarbital and rifampin , can increase the metabolism of chloramphenicol , decreasing chloramphenicol serum concentrations . Since chloramphenicol as a bacteriostatic drug may interfere with the bactericidal effects of penicillins in the treatment of meningitis or in other situations in which a rapid bactericidal effect is necessary , it is best to avoid concurrent therapy ; however , chloramphenicol and ampicillin are sometimes administered concurrently in pediatric patients . Chloramphenicol may cause a decrease in the hepatic metabolism of phenobarbital , phenytoin and warfarin , resulting in delayed elimination and increased blood concentrations. Concurrent use with vitamin B12 may antagonize hematopoietic response to vitamin B 12.

CBC with reticulocyte and platelet counts; Periodic liver and renal function tests ; Serum drug concentration.