Chloramphenicol is a bacteriostatic antibiotic with a broad spectrum of activity against both Gram-positive and Gram-negative bacteria, as well as certain other microorganisms. It functions by inhibiting bacterial protein synthesis, binding to the 50S ribosomal subunit, thereby preventing peptide bond formation. This mechanism makes it a valuable agent in treating serious infections, particularly when other antibiotics are ineffective or contraindicated. Its use is typically reserved for severe cases due to potential serious adverse effects, underscoring the necessity of medical supervision.

Features

• Chemical name: D-threo-(-)2,2-dichloro-N-[β-hydroxy-α-(hydroxymethyl)-p-nitrophenethyl]acetamide
• Available forms: Oral capsules, ophthalmic preparations (ointment and solution), intravenous injection
• Molecular formula: C₁₁H₁₂Cl₂N₂O₅
• Mechanism of action: Inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit
• Spectrum: Effective against a wide range of bacteria, including Haemophilus influenzae, Salmonella typhi, Rickettsia, and certain anaerobes

Benefits

• Highly effective against multidrug-resistant bacterial strains where other antibiotics fail
• Rapid bacteriostatic action, helping to control infection progression quickly
• Broad-spectrum coverage reduces the need for combination antibiotic therapy in certain cases
• Available in multiple formulations allowing targeted treatment (systemic, ocular)
• Cost-effective option in regions with limited access to newer broad-spectrum antibiotics
• Proven efficacy in life-threatening infections such as meningitis and typhoid fever

Common use

Chloramphenicol is indicated for serious infections caused by susceptible organisms. Typical applications include bacterial meningitis, particularly when caused by H. influenzae, Neisseria meningitidis, or Streptococcus pneumoniae in penicillin-allergic patients. It is also used for typhoid fever caused by Salmonella typhi, Rickettsial diseases, and other severe infections where benefit outweighs risk. Ophthalmic formulations are commonly prescribed for bacterial conjunctivitis. Its use is generally restricted to situations where less hazardous agents are ineffective or contraindicated.

Dosage and direction

Dosage must be individualized based on severity of infection, susceptibility of the pathogen, and patient factors. For adults, typical oral or intravenous dosage is 50 mg/kg/day divided every 6 hours, not to exceed 4 g daily. For severe infections like meningitis, higher doses up to 100 mg/kg/day may be used initially. Pediatric dosing is 50-75 mg/kg/day divided every 6 hours. Ophthalmic ointment or solution is applied every 3-6 hours depending on severity. Treatment should continue for at least 48 hours after symptoms disappear and fever subsides. Complete full course as prescribed.

Precautions

Use with extreme caution due to risk of fatal aplastic anemia, which may occur weeks or months after therapy. Monitor complete blood counts before and during therapy. Avoid unnecessary use. Use protective measures during preparation and administration to prevent exposure. Not recommended for trivial infections or prophylaxis. Exercise caution in patients with hepatic or renal impairment, requiring dosage adjustment. May cause gray baby syndrome in neonates. Inform patients to report any unusual bleeding, bruising, or sore throat immediately.

Contraindications

Hypersensitivity to chloramphenicol or any component of the formulation. Contraindicated in patients with history of chloramphenicol-induced blood dyscrasias. Avoid use in treating trivial infections or as prophylactic agent. Not recommended for neonates, especially premature infants, due to risk of gray baby syndrome. Avoid concurrent use with drugs that suppress bone marrow function. Contraindicated in patients with hepatic impairment that prevents metabolic inactivation of the drug.

Possible side effect

• Hematologic: Aplastic anemia, bone marrow suppression, leukopenia, thrombocytopenia, granulocytopenia
• Gastrointestinal: Nausea, vomiting, diarrhea, glossitis, stomatitis
• Neurologic: Optic neuritis, peripheral neuritis, headache, depression, confusion
• Hypersensitivity: Rash, fever, angioedema, anaphylaxis
• Other: Gray baby syndrome (in neonates), superinfection, blurred vision (with ophthalmic use)

Drug interaction

• Warfarin: Enhanced anticoagulant effect, increased risk of bleeding
• Phenytoin: Increased phenytoin levels, risk of toxicity
• Oral hypoglycemics: Enhanced hypoglycemic effect
• Cyclophosphamide: Reduced efficacy of cyclophosphamide
• Vitamin B12: Impaired response to vitamin B12 in anemia treatment
• Barbiturates: Reduced chloramphenicol efficacy, possible decreased barbiturate metabolism

Missed dose

If a dose is missed, take it as soon as remembered. However, if it is almost time for the next dose, skip the missed dose and continue with the regular schedule. Do not double the dose to make up for a missed one. Maintaining consistent antibiotic levels is crucial for effectiveness, but occasional missed doses are less critical than risking overdose. For ophthalmic preparations, apply the missed dose as soon as possible unless close to next scheduled application.

Overdose

Symptoms of overdose include nausea, vomiting, altered mental status, and gray baby syndrome in infants characterized by abdominal distension, cyanosis, vasomotor collapse. Hematologic toxicity may occur. Treatment is supportive and symptomatic. There is no specific antidote. Gastric lavage may be beneficial if ingestion was recent. Hemodialysis is not effective due to high protein binding. Monitor blood counts closely for several weeks after overdose. In cases of accidental ingestion, seek immediate medical attention.

Storage

Store at controlled room temperature (15-30°C or 59-86°F). Protect from light and moisture. Keep oral and intravenous formulations in tightly closed containers. Ophthalmic solutions and ointments should not be frozen. Keep all medications out of reach of children and pets. Do not use after expiration date. Do not transfer medications to other containers. Discard any unused portion of oral suspension after 14 days. Do not flush medications down toilet or pour into drain unless instructed.

Disclaimer

This information is for educational purposes only and does not constitute medical advice. Chloramphenicol is a potent antibiotic with serious potential side effects and must be used only under direct medical supervision. Never self-medicate with this drug. Always consult a healthcare professional for proper diagnosis and treatment recommendations. The benefits and risks must be carefully weighed before initiation of therapy. This information may not cover all possible uses, directions, precautions, or interactions.

Reviews

“Chloramphenicol remains a critical antibiotic in our arsenal against multidrug-resistant organisms. While its hematologic risks are significant, in life-threatening meningitis cases where other options have failed, it has proven invaluable. Requires meticulous monitoring but can be lifesaving.” - Infectious Disease Specialist, 15 years experience

“In ophthalmology, chloramphenicol ointment is remarkably effective for bacterial conjunctivitis. We reserve it for cases resistant to newer agents. Patients respond quickly, though we always warn about potential side effects and never prescribe prolonged courses.” - Ophthalmologist, 8 years experience

“The risk of aplastic anemia means we only use chloramphenicol when absolutely necessary, but for typhoid fever in certain endemic areas, it’s still among the most effective treatments available. Strict blood monitoring is essential throughout therapy.” - Tropical Medicine Physician, 20 years experience