What Is Chloramphenicol and How Does It Work?

Chloramphenicol is prescription intravenous antibiotic for treatment of serious infections and systemic infections.

  • Chloramphenicol is available under the following different brand names: Chloramphenicol IV and Chloromyectin. These brand names are discontinued in the U.S.

What Are Dosages of Chloramphenicol?

Dosages of Chloramphenicol:

Injectable solution

  • 1,000 mg/vial

Dosage Considerations – Should be Given as Follows:

Serious Infections Caused by Susceptible Strains


  • 50 mg/kg/day intravenously divided every 6 hours; in exceptional cases, patients with moderately resistant organisms or severe infections may require increased dosage up to 100 mg/kg/day; decrease these high doses as soon as possible

Systemic Infections


  • Infants and children: As in adults; when adequate cerebrospinal fluid concentrations are desired, may require up to 100 mg/kg/day; however, should reduce dose to 50 mg/kg/day as soon as possible
  • Infants and children with suspected immature metabolic functions: 25 mg/kg/day divided every 6 hours will usually produce therapeutic concentrations of the drug in the blood

Neonates (Infants younger than 28 days)


  • Loading dose (LD): 20 mg/kg intravenously once; give maintenance dose 12 hours after loading dose

Maintenance Dose

  • Infants younger than 7 days old: 25 mg/kg/day intravenously every 24 hours
  • Infants over 7 days old, less than 2000 g: 25 mg/kg/day intravenously every 24 hours
  • Infants over 7 days old, over 2000 g: 50 mg/kg/day intravenously every 12 hours

Other Information


  • Peaks 10-20 mg/l, troughs 5-10 mg/l

Other Indications and Uses


  • Use only as an alternative for treatment of meningitis, typhoid, or rickettsial infection

What Are Side Effects Associated with Using Chloramphenicol?

Common side effects of chloramphenicol include:

  • not enough red blood cells produced (aplastic anemia)
  • bone marrow suppression
  • diarrhea
  • inflammation of the small intestine and the colon (enterocolitis)
  • accumulation of chloramphenicol especially in newborns (gray syndrome)
  • headache
  • nausea
  • nightmares
  • inflammation of the optic nerve
  • weakness and numbness in your hands and feet
  • rash
  • inflamed and sore mouth
  • vomiting

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

What Other Drugs Interact with Chloramphenicol?

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

Chloramphenicol has no known severe interactions with other drugs.

This information does not contain all possible interactions or adverse effects. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns, or for more information about this medicine.

What Are Warnings and Precautions for Chloramphenicol?


Serious and fatal blood dyscrasias, including aplastic anemia, hypoplastic anemia, thrombocytopenia, and granulocytopenia, have occurred after short-term and prolonged therapy.

Monitor complete blood count (CBC) frequently in all patients. Use only in serious infections.

This medication contains chloramphenicol. Do not take Chloramphenicol IV and Chloromyectin if you are allergic to chloramphenicol or any ingredients contained in this drug.

Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately.


  • Hypersensitivity
  • Do not use oral or topical; not for use in trivial infections or for prophylaxis
  • Avoid during breastfeeding

Effects of Drug Abuse

  • None

Short-Term Effects

  • See "What Are Side Effects Associated with Using Chloramphenicol?"

Long-Term Effects

  • See "What Are Side Effects Associated with Using Chloramphenicol?"


  • Kidney or liver impairment (not studied in these conditions)
  • Carotenoderma (yellowing of the skin) was reported 4-6 weeks after initiating high doses
  • When antioxidant vitamins, including beta-carotene, are used together, they might interfere with healing following angioplasty
  • May increase cardiovascular risk (coronary artery disease, cardiovascular mortality), especially in current smokers
  • Increased incidence of lung cancer following chloramphenicol supplementation has been reported in clinical trials of adult smokers and those exposed to asbestos

Pregnancy and Lactation

  • Use chloramphenicol with caution during pregnancy if the benefits outweigh the risks. Animal studies show risk and human studies are not available or neither animal nor human studies were done.
  • Chloramphenicol enters breast milk; discontinue the drug or do not breastfeed

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