Introduction

Name

• Chloramphenicol.

Class of drug

• Bacteriostatic antibiotic.

Description

Chemical name

• [R-(R*,R*)]-2,2-dichloro-N-[2-Hydroxy-1-(hydroxymethyl)-2-(4-nitrophenyl)ethyl]acetamide.

Molecular formula

• C11H12Cl2N2O5.

Physical properties

• Solution.
• Tablets.

Storage requirements

• Refrigeration of solution preferable between 2-8°C.
• Protect from light.

Uses

Indications

Gram-positive infections

• Streptococci Streptococcus spp.
• Staphylococci Staphylococcus spp.

Gram-negative infections

• Salmonella spp Salmonella spp.
• Haemophilus spp.

Anaerobic infections

• Clostridium spp Clostridia spp.
• Bacteroides fragilis Bacteroides fragilis.

Other sensitive organisms

• Chlamydia spp Chlamydia psittaci.
• Mycoplasma spp Mycoplasmas and ureaplasmas.
• Rickettsia spp.
• Resistant organisms are Nocardia Nocardia spp , Mycobacterium spp.
• Acquired resistance may occur in Enterobacteriacae Enterobacter aerogenes (aerobacter aerogenes).

Administration

Precautions

Interactions

with other drugs

Anticonvulsants (pentobarbitone, phenobarbitone and phenytoin)

• Chloramphenicol is an irreversible inhibitor of hepatic cytochrome P450 dependent enzymes and so increases the plasma levels of these drugs Pentobarbital Phenobarbital Phenytoin.
• Recovery from the inhibitory effects requires synthesis of new liver enzymes and can take up to 3 weeks.

Iron salts and Vitamin B12

• Decreased hematologic response may be seen Vitamin B12.

Rifampicin

• Accelerates the metabolism of chloramphenicol, thus decreasing serum levels.

Adverse Reactions

Further Reading

Publications

Refereed papers

• Recent references from PubMed and VetMedResource.

Other sources of information

• BSAVA Small Animal Formulary. Ramsey I (2017) 9th edn. Cheltenham: BSAVA.