Chloramphenicol (Chloromycetin®)

Overview

Chloramphenicol is an antibiotic used in dogs and cats. Chloramphenicol inhibits bacteria by suppressing growth. It is effective against a broad range of bacteria and also may be effective against some one-celled pathogenic organisms (protozoa).

Chloramphenicol is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian.

Brand Names and Other Names

This drug is registered for use in animals and humans.

Human formulation: Chloromycetin® (Parke-Davis) and various generic formulations.

Veterinary formulation: Available as the generic formulation.

Uses of Chloramphenicol

Chloramphenicol is used in both dogs and cats to treat a variety of bacterial infections, including skin infections, wound infections, bone infections, infections of the central nervous system (encephalitis, meningitis), pneumonia, and infections of the intestinal tract (such as diarrhea). 

Chloramphenicol has been used to treat protozoa infections in animals.

Chloramphenicol has been used to treat tick-transmitted diseases in animals, such as Rocky Mountain spotted fever.

Chloramphenicol is not effective against infections caused by parasites (intestinal worms), mites, viruses, or fungi.

Precautions and Side Effects

While generally safe and effective when prescribed by a veterinarian, chloramphenicol can cause side effects in some animals.

Chloramphenicol should not be used in animals with known hypersensitivity or allergy to the drug.

The most serious adverse effect in people is an irreversible suppression of the blood-forming cells (aplastic anemia). For this reason, chloramphenicol exposure in humans should be limited as much as possible. 

This reaction (aplastic anemia) is not possible in animals, however chloramphenicol may suppress the blood-forming cells in a reversible manner if administered for prolonged periods at high doses. In cats, for example, this reaction may be observed after two weeks of continuous treatment.

Do not administer chloramphenicol to pregnant animals or very young animals.

Chloramphenicol may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with chloramphenicol. Such drugs include various other antibiotics, phenobarbital and cyclophosphamide.

Cats are most susceptible to adverse reactions from chloramphenicol.

Vomiting, lack of appetite and diarrhea are possible from chloramphenicol.

How Chloramphenicol Is Supplied

Chloramphenicol is available in a 250 mg capsule and 100 mg, 250 mg and 500 mg tablets. There is a liquid form (chloramphenicol palmitate) available in an oral suspension. 

Dosing Information

Medication should never be administered without first consulting your veterinarian. 

The usual dose is 25 mg per pound (50 mg/kg) orally every eight hours for dogs, and 6 to 10 mg per pound (12.5 to 20 mg/kg) every 12 hours orally for cats. 

The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse or prevent the development of resistance.