Version July 2025
Serious and fatal blood dyscrasias (aplastic anemia, hypoplastic anemia, thrombocytopenia, and granulocytopenia) are known to occur after the administration of chloramphenicol. In addition, there have been reports of aplastic anemia attributed to chloramphenicol which later terminated in leukemia. Blood dyscrasias have occurred after both short-term and prolonged therapy with this drug. Chloramphenicol must not be used when less potentially dangerous agents will be effective. It must not be used in the treatment of trivial infections or where it is not indicated, as in colds, influenza, infections of the throat; or as a prophylactic agent to prevent bacterial infections.
It is essential that adequate blood studies be made during treatment with the drug. While blood studies may detect early peripheral blood changes, such as leukopenia, reticulocytopenia, or granulocytopenia, before they become irreversible, such studies cannot be relied on to detect bone marrow depression prior to development of aplastic anemia. To facilitate appropriate studies and observation during therapy, it is desirable that patients be hospitalized.
Dosage guidance:
Safety: Follow serum concentrations closely to monitor for toxicity and efficacy in neonates due to variability in metabolism; use should be restricted to treatment of serious infections caused by susceptible organisms when less toxic drugs are ineffective (ie, resistance) or contraindicated.
Dosage form information: Only chloramphenicol sodium succinate (IV formulation) is available in the United States; chloramphenicol palmitate (oral formulation) is not available.
Infection, severe (alternative agent):
Weight-directed dosing: Limited data available (Ref):
Preterm and term neonates:
<1,200 g and ≤28 days: IV: 22 mg/kg/dose every 24 hours.
1,200 to 2,000 g and ≤7 days: IV: 25 mg/kg/dose every 24 hours.
Age-directed dosing: Limited data available; dosing regimens variable:
Preterm neonates, or term neonates with PNA ≤7 days: IV: 25 mg/kg/dose every 24 hours or initiation with a loading dose of 20 mg/kg followed 12 hours later by a maintenance regimen of 12.5 mg/kg/dose every 12 hours (Ref).
Term neonates with PNA >7 days: IV: 25 mg/kg/dose every 12 hours or 12.5 mg/kg/dose every 6 hours (Ref).
Plague (Yersinia pestis), treatment: Note: Consult public health officials for event-specific recommendations (Ref).
Bubonic, pharyngeal, pneumonic, or septicemic plague (alternative agent): Note: Treatment is typically continued for 10 to 14 days (Ref). Although guidelines state that chloramphenicol may also be administered IM in the neonatal population for this indication, the IM route is typically discouraged due to potentially lower serum concentrations.(Ref).
Term or preterm neonates 37 to 44 weeks postmenstrual age (PMA):
PNA ≤14 days: IV: 6.25 mg/kg/dose every 6 hours (Ref).
PNA 15 to 28 days: IV: 12.5 mg/kg/dose every 6 hours (Ref).
Plague meningitis: Note: Treat for 10 to 14 days as part of an appropriate combination regimen. If chloramphenicol is added on to existing regimen for development of secondary plague meningitis, continue entire regimen for an additional 10 days (Ref).
Term or preterm neonates 37 to 44 weeks PMA:
PNA ≤7 days: IV: 25 mg/kg/dose every 24 hours (Ref).
PNA 8 to 28 days: IV: 25 mg/kg/dose every 12 hours (Ref).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
Dosing: Altered Kidney Function: Neonatal: There are no specific dosage adjustments provided in the manufacturer's labeling; however, use with caution; reduced dosage and serum concentration monitoring is recommended.
Dosing: Altered Liver Function: Neonatal: There are no specific dosage adjustments provided in the manufacturer's labeling; however, use with caution; reduced dosage and serum concentration monitoring is recommended.
Dosage guidance:
Safety: Follow serum concentrations closely to monitor for toxicity. Use should be restricted to treatment of serious infections when less toxic drugs are ineffective (ie, resistance) or contraindicated.
Dosage form information: Only chloramphenicol sodium succinate (IV formulation) is available in the United States; chloramphenicol palmitate (oral formulation) is not available.
Infection, severe (alternative agent): Infants, Children, and Adolescents: IV: 12.5 to 25 mg/kg/dose every 6 hours; maximum dose: 1,000 mg/dose (Ref).
Meningitis (alternative agent): Limited data available: Infants, Children, and Adolescents: IV: 18.75 to 25 mg/kg/dose every 6 hours; maximum dose: 1,000 mg/dose (Ref).
Plague (Yersinia pestis), treatment: Note: Consult public health officials for event-specific recommendations (Ref).
Bubonic, pharyngeal, pneumonic, or septicemic plague (alternative agent): Infants, Children, and Adolescents: IV: 12.5 to 25 mg/kg/dose every 6 hours for 10 to 14 days; maximum dose: 1,000 mg/dose. For severe infections, dosing at the higher end of the range may be needed (25 mg/kg/dose); decrease dose to 12.5 mg/kg/dose as soon as clinically feasible (Ref).
Plague meningitis: Infants, Children, and Adolescents: IV: 25 mg/kg/dose every 6 hours for 10 to 14 days as part of an appropriate combination regimen; maximum dose: 1,000 mg/dose. If chloramphenicol is added on to existing regimen for development of secondary plague meningitis, continue entire regimen for an additional 10 days (Ref).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
There are no dosage adjustments provided in the manufacturer's labeling. Use with caution; reduced dosage and serum concentration monitoring is recommended.
There are no dosage adjustments provided in the manufacturer's labeling. Use with caution; reduced dosage and serum concentration monitoring is recommended.
(For additional information see "Chloramphenicol (systemic): Drug information")
Usual dosage range: IV: 50 mg/kg/day in divided doses every 6 hours; an increased dosage up to 100 mg/kg/day may be required in some cases, but should be decreased as soon as possible (manufacturer's labeling). Maximum daily dose: 4 g/day (Ref).
Plague (Yersinia pestis), treatment:
Note: Consult public health officials for event-specific recommendations. Dose based on total body weight, including in patients with obesity and those who are underweight (Ref).
Bubonic, pharyngeal, pneumonic, or septicemic plague (alternative agent): IV: 12.5 mg/kg (maximum: 1 g /dose) every 6 hours for 10 to 14 days and for at least a few days after clinical resolution (Ref). For severe infections, a higher dose (25 mg/kg [maximum: 1 g/dose] every 6 hours) may be needed; reduce dose to 12.5 mg/kg (maximum: 1 g/dose) every 6 hours as soon as possible with clinical improvement (Ref).
Plague meningitis: Note: For initial treatment of patients who present with meningitis symptoms, use as part of an appropriate combination regimen; add chloramphenicol to existing antimicrobial regimen in patients who develop secondary plague meningitis.
IV: 25 mg/kg (maximum: 1 g/dose) every 6 hours; may reduce dose to 12.5 mg/kg (maximum: 1 g/dose) every 6 hours after clinical improvement. Recommended duration is 10 to 14 days and for at least a few days after clinical resolution when used for initial treatment (Ref); for secondary plague meningitis when chloramphenicol is added to existing therapy, continue entire regimen for an additional 10 days (Ref).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
There are no specific dosage adjustments provided in the manufacturer's labeling; however, dosage adjustment may be necessary. Use with caution; monitor serum concentrations.
There are no specific dosage adjustments provided in the manufacturer's labeling; however, dosage adjustments may be necessary. Use with caution; monitor serum concentrations.
The following adverse drug reactions are derived from product labeling unless otherwise specified.
Postmarketing:
Dermatologic: Acute generalized exanthematous pustulosis (Lee 1999), skin rash (Haile 1977)
Gastrointestinal: Diarrhea (Haile 1977), glossitis (Haile 1977), nausea (Haile 1977), vomiting (Haile 1977)
Genitourinary: Hemoglobinuria (paroxysmal nocturnal)
Hematologic & oncologic: Aplastic anemia (Schmitt-Gräff 1981), bone marrow depression (Ferguson 1953), glucose-6-phosphate dehydrogenase deficiency anemia (Haile 1977), granulocytopenia (Poulton 1955), hypoplastic anemia (Todd 1954), immune thrombocytopenia (Poulton 1955), leukemia (Haile 1977), leukopenia (Haile 1977), neutropenia (Haile 1977), pancytopenia, sideroblastic anemia (Haile 1977), thrombocytopenia (Haile 1977)
Hypersensitivity: Hypersensitivity reaction (including angioedema) (Haile 1977)
Immunologic: Jarisch-Herxheimer reaction (Haile 1977)
Nervous system: Confusion (Levine 1970), delirium (Levine 1970), depression, encephalopathy (including asterixis, hallucination) (Levine 1970), headache
Ophthalmic: Optic atrophy (Keith 1964), optic neuritis (Keith 1964)
Respiratory: Neonatal cyanosis (gray syndrome) (Mulhall 1983)
Hypersensitivity to chloramphenicol or any component of the formulation; treatment of trivial or viral infections; bacterial prophylaxis
Concerns related to adverse effects:
• Gray syndrome: Characterized by cyanosis, abdominal distention, vasomotor collapse (often with irregular respiration), and death. Reaction appears to be associated with serum levels ≥50 mcg/mL (Powell 1982).
• Superinfection: Prolonged use may result in fungal or bacterial superinfection, including Clostridium difficile–associated diarrhea (CDAD) and pseudomembranous colitis; CDAD has been observed >2 months postantibiotic treatment.
Disease-related concerns:
• Hepatic impairment: Use with caution; reduced dosage and serum concentration monitoring is recommended.
• Renal impairment: Use with caution; reduced dosage and serum concentration monitoring is recommended.
Special populations:
• Glucose 6-phosphate dehydrogenase deficiency: Use with caution in patients with glucose 6-phosphate dehydrogenase deficiency.
• Neonates: Use in premature and full-term neonates and infants has resulted in “gray syndrome" characterized by cyanosis, abdominal distention (with or without emesis), vasomotor collapse (often with irregular respiration), and death; progression of symptoms is rapid; prompt termination of therapy required. Reaction may result from drug accumulation caused by immature hepatic or renal function in neonates and infants.
Other warnings/precautions:
• Appropriate use: Avoid prolonged or repeated courses of treatment.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Solution Reconstituted, Intravenous [preservative free]:
Generic: 1 g (1 ea)
Yes
Solution (reconstituted) (Chloramphenicol Sod Succinate Intravenous)
1 g (per each): $58.38
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Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Solution Reconstituted, Intravenous:
Chloromycetin Succinate: 1 g (1 ea)
Sodium content of 1 g injection: 2.25 mEq.
Parenteral:
IM: IM administration is discouraged; may be associated with lower serum concentrations, potentially resulting in lower efficacy (Ref).
IV push: Administer over at least 1 minute.
Intermittent IV infusion: Infuse over 30 to 60 minutes (Ref). In neonates, some centers have administered as an intermittent IV infusion over 15 minutes (Ref).
IV: For IV use only; do not administer IM. Can be administered IVP over at least 1 minute at a concentration of 100 mg/mL.
Hazardous agent (NIOSH 2024 [table 1]).
Use appropriate precautions for receiving, handling, storage, preparation, dispensing, transporting, administration, and disposal. Follow NIOSH and USP 800 recommendations and institution-specific policies/procedures for appropriate containment strategy (NIOSH 2023; NIOSH 2024; USP-NF 2020).
Note: Facilities may perform risk assessment of some hazardous drugs to determine if appropriate for alternative handling and containment strategies (USP-NF 2020). Refer to institution-specific handling policies/procedures.
Store intact vials at 20°C to 25°C (68°F to 77°F).
Treatment of serious infections caused by susceptible organisms when less toxic drugs are ineffective or contraindicated (IV [chloramphenicol sodium succinate]: FDA approved in all ages).
Note: Oral chloramphenicol (palmitate or base) is not available in the United States.
Chloromycetin may be confused with chlorambucil, Chlor-Trimeton
KIDs List: Chloramphenicol, when used in neonates, is identified on the Key Potentially Inappropriate Drugs in Pediatrics (KIDs) list and should be avoided due to risk of gray baby syndrome unless serum concentration monitoring used (strong recommendation; high quality of evidence) (PPA [Meyers 2020]).
Inhibits CYP2C9 (Weak);
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program by clicking on the “Launch drug interactions program” link above.
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program
Bacillus clausii: Antibiotics may decrease therapeutic effects of Bacillus clausii. Management: Bacillus clausii should be taken in between antibiotic doses during concomitant therapy. Risk D: Consider Therapy Modification
BCG (Intravesical): Antibiotics may decrease therapeutic effects of BCG (Intravesical). Risk X: Avoid
BCG Vaccine (Immunization): Antibiotics may decrease therapeutic effects of BCG Vaccine (Immunization). Risk C: Monitor
CefTAZidime: Chloramphenicol (Systemic) may decrease therapeutic effects of CefTAZidime. Management: Consider using a different combination of antimicrobials, especially if bactericidal activity is desired. If these agents are combined, monitor for reduced antimicrobial effectiveness and/or therapeutic failure. Risk D: Consider Therapy Modification
Cholera Vaccine: Antibiotics may decrease therapeutic effects of Cholera Vaccine. Management: Avoid cholera vaccine in patients receiving systemic antibiotics, and within 14 days following the use of oral or parenteral antibiotics. Risk X: Avoid
CycloSPORINE (Systemic): Chloramphenicol (Systemic) may increase serum concentration of CycloSPORINE (Systemic). Management: Cyclosporine dose reductions will likely be required with initiation of concurrent chloramphenicol. Monitor cyclosporine concentrations and response closely following initiation and/or discontinuation of chloramphenicol. Risk D: Consider Therapy Modification
Fecal Microbiota (Live) (Oral): May decrease therapeutic effects of Antibiotics. Risk X: Avoid
Fecal Microbiota (Live) (Rectal): Antibiotics may decrease therapeutic effects of Fecal Microbiota (Live) (Rectal). Risk X: Avoid
Fosphenytoin: May decrease serum concentration of Chloramphenicol (Systemic). Fosphenytoin may increase serum concentration of Chloramphenicol (Systemic). Chloramphenicol (Systemic) may increase serum concentration of Fosphenytoin. Risk C: Monitor
Immune Checkpoint Inhibitors (Anti-PD-1, -PD-L1, and -CTLA4 Therapies): Antibiotics may decrease therapeutic effects of Immune Checkpoint Inhibitors (Anti-PD-1, -PD-L1, and -CTLA4 Therapies). Risk C: Monitor
Lactobacillus and Estriol: Antibiotics may decrease therapeutic effects of Lactobacillus and Estriol. Risk C: Monitor
Myelosuppressive Agents: May increase myelosuppressive effects of Chloramphenicol (Systemic). Risk X: Avoid
PHENobarbital: May decrease serum concentration of Chloramphenicol (Systemic). Chloramphenicol (Systemic) may increase serum concentration of PHENobarbital. Risk C: Monitor
Phenytoin: May decrease serum concentration of Chloramphenicol (Systemic). Phenytoin may increase serum concentration of Chloramphenicol (Systemic). Chloramphenicol (Systemic) may increase serum concentration of Phenytoin. Risk C: Monitor
Primidone: Chloramphenicol (Systemic) may increase active metabolite exposure of Primidone. Specifically, the concentrations of phenobarbital may be increased. Primidone may decrease serum concentration of Chloramphenicol (Systemic). Risk C: Monitor
RifAMPin: May increase metabolism of Chloramphenicol (Systemic). Risk C: Monitor
Sodium Picosulfate: Antibiotics may decrease therapeutic effects of Sodium Picosulfate. Management: Consider using an alternative product for bowel cleansing prior to a colonoscopy in patients who have recently used or are concurrently using an antibiotic. Risk D: Consider Therapy Modification
Sulfonylureas: Chloramphenicol (Systemic) may increase serum concentration of Sulfonylureas. Risk C: Monitor
Tacrolimus (Systemic): Chloramphenicol (Systemic) may increase serum concentration of Tacrolimus (Systemic). Management: Reduce the tacrolimus dose and monitor tacrolimus whole blood concentrations frequently, beginning within 1 to 3 days of chloramphenicol initiation. Further tacrolimus dose adjustments should be guided by continued monitoring of tacrolimus levels. Risk D: Consider Therapy Modification
Typhoid Vaccine: Antibiotics may decrease therapeutic effects of Typhoid Vaccine. Only the live attenuated Ty21a strain is affected. Management: Avoid use of live attenuated typhoid vaccine (Ty21a) in patients being treated with systemic antibacterial agents. Postpone vaccination until 3 days after cessation of antibiotics and avoid starting antibiotics within 3 days of last vaccine dose. Risk D: Consider Therapy Modification
Vitamin B12: Chloramphenicol (Systemic) may decrease therapeutic effects of Vitamin B12. Risk C: Monitor
Vitamin K Antagonists: CYP2C9 Inhibitors (Weak) may increase serum concentration of Vitamin K Antagonists. Risk C: Monitor
May have increased dietary need for riboflavin, pyridoxine, and vitamin B12. Some products may contain sodium.
Chloramphenicol crosses the placenta producing cord concentrations approaching maternal serum concentrations. An increased risk of teratogenic effects has not been associated with the use of chloramphenicol in pregnancy (Czeizel 2000; Heinonen 1977). "Gray Syndrome" has occurred in premature infants and newborns receiving chloramphenicol.
Chloramphenicol may be used as an alternative agent for the treatment of Rocky Mountain spotted fever in pregnant patients although caution should be used when administration occurs during the third trimester (CDC [Biggs 2016]).
Untreated plague (Yersinia pestis) infections in pregnant patients may result in hemorrhage (including postpartum hemorrhage), maternal and fetal death, preterm birth, and stillbirth. Limited data suggest maternal-fetal transmission of Y. pestis can occur if not treated. Pregnant patients should be treated for Y. pestis; parenteral antibiotics are preferred for initial treatment when otherwise appropriate. Chloramphenicol may be used as an alternative antibiotic for treating pregnant patients with bubonic, pharyngeal, pneumonic, or septicemic plague (doses at the lower end of the adult dosing range should be sufficient for most patients). Recommendations for treating pregnant patients with plague meningitis are the same as in nonpregnant patients. Chloramphenicol can be added to the antibiotic regimen for treatment of secondary plague meningitis (CDC [Nelson 2021]).
CBC with differential and platelet counts (baseline and every 2 days during therapy), serum iron level, iron-binding capacity, periodic liver and kidney function tests, serum drug concentration.
Target concentrations:
Peak:
Neonates: 15 to 25 mg/L (SI: 46.3 to 77.3 mcmol/L) (Mulhall 1983).
Infants, Children, and Adolescents: 15 to 30 mg/L (SI: 46.3 to 92.7 mcmol/L) (Balbi 2004; Coakley 1992; Panuganti 2022); some suggest a maximum peak concentration of 25 mg/L (SI: 77.3 mcmol/L) to avoid bone marrow suppression (Balbi 2004; Hammett-Stabler 1998; Ismail 1998).
Trough: 5 to 10 mcg/mL (SI: 15.5 to 30.9 mcmol/L) (Ambrose 1984).
Timing of serum samples: Obtain serum samples after 2 to 3 doses and monitor weekly or more frequently if clinically indicated (Balbi 2004; Ismail 1998). Obtain peak concentrations 0.5 to 2 hours after completion of IV dose, and trough at the end of the dosing interval (ie, immediately before next dose) (Coakely 1992; Hammett-Stabler 1998; Ismail 1998; Panuganti 2022).
Reversibly binds to 50S ribosomal subunits of susceptible organisms preventing amino acids from being transferred to growing peptide chains thus inhibiting protein synthesis
Distribution: To most tissues and body fluids (Ambrose 1984); good cerebrospinal fluid (CSF) and brain penetration.
CSF concentration with uninflamed meninges: 21% to 50% of plasma concentration.
CSF concentration with inflamed meninges: 45% to 89% of plasma concentration.
Chloramphenicol: Vd:
Infants ≥3 months, Children, and Adolescents: 0.71 ± 0.52 L/kg (Nahata 1981).
Adults: 0.81 ± 0.18 L/kg (Burke 1982).
Chloramphenicol succinate: Vd:
Infants ≥2 months, Children, and Adolescents: 2.1 ± 0.77 L/kg (Nahata 1981).
Adults: 0.379 ± 0.128 L/kg (Burke 1982).
Protein binding: Chloramphenicol: ~60%; decreased with hepatic or renal dysfunction and 30% to 40% in newborn infants (Ambrose 1984).
Metabolism:
Chloramphenicol: Hepatic to metabolites (inactive) (Ambrose 1984).
Chloramphenicol succinate: Hydrolyzed in the liver, kidney, and lungs to chloramphenicol (active) (Ambrose 1984).
Bioavailability:
Chloramphenicol: Oral: ~80% (Ambrose 1984).
Chloramphenicol succinate: IV: ~70%; highly variable, dependent upon rate and extent of metabolism to chloramphenicol (Ambrose 1984).
Half-life elimination:
Chloramphenicol:
Neonates:
PNA 1 to 4 days (GA 25 to 39 weeks): 18.5 to 35 hours (Rajchgot 1983).
PNA 8 to 30 days (GA 25 to 38 weeks): 6 to 11.5 hours (Rajchgot 1983).
Infants, Children, and Adolescents: ~4 to 5 hours (Friedman 1979; Kauffman 1981; Nahata 1981; Sack 1980); prolonged and more variable in infants (Kauffman 1981; Powell 1982); range: 1.7 to 12 hours (Kauffman 1981).
Adults: ~4 hours (Ambrose 1984).
Hepatic disease: Prolonged (Ambrose 1984).
Excretion: Urine (~30% as unchanged chloramphenicol succinate in adults, 6% to 80% in children; 5% to 15% as chloramphenicol) (Ambrose 1984; Powell 1982).
