| Structure/Class |
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| Pharmacodynamics |
- Chloramphenicol functions as an inhibitor of microbial protein synthesis by binding reversibly to the 50S subunit of the bacterial ribosome.
- It is a bacteriostatic drug
- It has a very broad spectrum – covers Gram+ve, Gram-ve, aerobic and anaerobic bacteria.
- Its activity against intracellular organisms is against Rickettsia, but not against Chlamydia.
- H.influenzae, Neisseria and bacteroides are all susceptible.
- Hence, the indications are as follows:
- Treatment of meningitis in patients with penicillin hypersensitivity.
- Topically, in eye infections
- Serious rickettsial infections, e.g. typhus or Rocky Mountain Spotted Fever
- Resistance is due to the formation of chloramphenicol acetyltransferase, which inactivates the drug.
|
| Absorption/administration |
- PO, IV, topical
|
| Distribution |
- Wide – penetrates cell membranes. CSF levels are the same as plasma.
|
| Metabolism |
- Inactivated by conjugation/glucuronidation. Therefore, dose must be markedly reduced in hepatic failure (but not renal failure)
- Also a strong inhibitor of microsomal enzymes – leads to increased levels of phenytoin, warfarin and theophylline.
|
| Excretion |
- Urine, and a small amount in bile/faeces.
|
| Indications |
- Microsomal enzyme inhibitor
- Because chloramphenicol is bacteriostatic, it may reduce the activity of bactericidal drugs (e.g. penicillin/aminoglycosides)
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| Contraindications |
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| Special precautions |
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| Interactions |
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| Adverse events |
- GIT – causes nausea, vomiting and diarrhea
- Grey baby syndrome
- Aplastic anaemia (rare idiosyncratic reaction affecting 1:40000, it is dose and duration dependent)
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| Dosing/administration |
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| Toxicology |
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| Withdrawal syndrome |
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| Special notes |
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