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, specifically binding to the 50S ribosomal subunit. 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 situations where the benefits outweigh potential risks due to associated serious adverse effects.

Features

• Broad-spectrum activity against aerobic and anaerobic bacteria
• Available in oral, topical, and intravenous formulations
• Rapid tissue penetration and distribution
• Effective against multidrug-resistant organisms
• Well-established clinical efficacy profile

Benefits

• Provides effective treatment for serious bacterial infections when other antibiotics fail
• Offers rapid bactericidal action in high concentrations
• Demonstrates excellent penetration into cerebrospinal fluid and ocular tissues
• Effective against a wide range of pathogenic organisms including Salmonella typhi
• Can be used as first-line treatment for specific conditions like bacterial meningitis in resource-limited settings
• Available in multiple formulations for flexible administration routes

Common use

Chloramphenicol is primarily indicated for serious infections caused by susceptible organisms where less potentially dangerous therapeutic agents are ineffective or contraindicated. Common applications include treatment of bacterial meningitis caused by Haemophilus influenzae, Neisseria meningitidis, or Streptococcus pneumoniae. It is also used for rickettsial diseases, typhoid fever, and other Salmonella infections. Topical formulations are frequently employed for ocular infections including bacterial conjunctivitis. The drug may be considered for anaerobic infections, particularly those involving Bacteroides fragilis, and for infections caused by vancomycin-resistant enterococci in certain clinical scenarios.

Dosage and direction

Dosage must be individualized based on the severity of infection, susceptibility of the causative organism, and patient characteristics. For adults, typical intravenous or oral dosage ranges from 50-100 mg/kg/day divided into 4 equal doses, not to exceed 4 g daily. For severe infections like meningitis, doses up to 100 mg/kg/day may be employed. Pediatric dosing is weight-based at 50-75 mg/kg/day divided into 4 doses. Topical ophthalmic preparations are typically administered as 1-2 drops in the affected eye(s) every 3-6 hours. Treatment duration should be the shortest possible to achieve clinical cure, typically 5-14 days depending on infection type and response. Serum concentration monitoring is recommended when using high doses or prolonged therapy.

Precautions

Chloramphenicol requires careful clinical supervision due to potential serious adverse effects. Complete blood counts should be performed before therapy and every 2 days during treatment to monitor for hematologic toxicity. Hepatic and renal function should be assessed regularly. Use with extreme caution in patients with hepatic impairment, renal insufficiency, or pre-existing bone marrow depression. Avoid concurrent use with other drugs that may cause bone marrow suppression. Patients should be advised to report immediately any signs of infection, unusual bleeding, or fatigue. Pregnancy category C: use only if potential benefit justifies potential risk to fetus. Excreted in breast milk; nursing should be discontinued during treatment.

Contraindications

Chloramphenicol is contraindicated in patients with known hypersensitivity to chloramphenicol or any component of the formulation. Absolute contraindications include history of chloramphenicol-induced blood dyscrasias, previous bone marrow suppression from chloramphenicol therapy, and treatment of minor infections or as prophylactic medication. Should not be used for trivial infections, viral infections, or when less potentially dangerous agents would be effective. Contraindicated in infants under 2 weeks old due to risk of “gray baby syndrome.”

Possible side effect

The most serious adverse effect is bone marrow suppression, which may manifest as reversible dose-related anemia, leukopenia, and thrombocytopenia, or irreversible aplastic anemia. Gastrointestinal effects include nausea, vomiting, and diarrhea. Neurological effects may include optic neuritis, peripheral neuropathy, and headache. Hypersensitivity reactions ranging from skin rashes to anaphylaxis may occur. “Gray baby syndrome” in neonates characterized by abdominal distension, cyanosis, and cardiovascular collapse. Other potential effects include superinfection, fever, and mucosal candidiasis. Ophthalmic preparations may cause transient burning, stinging, or blurred vision.

Drug interaction

Chloramphenicol interacts significantly with numerous medications. It inhibits hepatic metabolism of warfarin, phenytoin, tolbutamide, and chlorpropamide, potentially increasing their effects and toxicity. Concurrent use with other bone marrow suppressants (cytotoxic drugs, radiation therapy) increases hematologic toxicity. May antagonize bactericidal activity of penicillins and aminoglycosides in some situations. Barbiturates and rifampin may decrease chloramphenicol levels by inducing hepatic enzymes. Alcohol may cause disulfiram-like reaction. Oral preparations may interfere with vitamin B12 absorption and response to iron therapy.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is almost time for the next scheduled dose. In that case, skip the missed dose and resume the regular dosing schedule. Do not double the dose to make up for a missed administration. Maintaining consistent serum levels is important for therapeutic efficacy, particularly in serious infections. If multiple doses are missed or vomiting occurs shortly after oral administration, contact healthcare provider for guidance on dose adjustment or potential need for alternative administration route.

Overdose

Acute overdose may cause nausea, vomiting, and gastrointestinal distress. Massive overdose can lead to cardiovascular collapse and bone marrow suppression. Symptoms of toxicity include grayish skin color, hypotension, metabolic acidosis, and cardiovascular failure, particularly in infants. Treatment is primarily supportive with gastric lavage if ingestion was recent. No specific antidote exists. Hemodialysis is not effective for removal due to high protein binding. Management should include monitoring of hematologic parameters for several weeks post-overdose. In cases of suspected overdose, immediate medical attention is required with supportive care including maintenance of adequate glomerular filtration and monitoring of cardiac function.

Storage

Store at controlled room temperature (15-30°C or 59-86°F). Protect from light and moisture. Keep container tightly closed. Do not freeze liquid formulations. Oral suspension should be discarded after 14 days when reconstituted. Intravenous solutions should be used immediately after preparation and not stored for extended periods. Keep all medications out of reach of children and pets. Do not use after expiration date printed on packaging. Properly discard any unused medication according to local regulations for pharmaceutical waste disposal.

Disclaimer

This information is provided for educational purposes only and does not constitute medical advice. Chloramphenicol is a potent antibiotic with serious potential adverse effects and should only be used under direct supervision of a qualified healthcare professional. The prescribing physician must carefully weigh benefits against risks for each individual patient. Always follow the specific instructions provided by your healthcare provider and the product labeling. Do not self-medicate with chloramphenicol or share medication with others. Report any adverse effects to your healthcare provider immediately.

Reviews

“Chloramphenicol remains an essential antibiotic in our formulary for multidrug-resistant bacterial meningitis cases. While we respect its toxicity profile, its cerebrospinal fluid penetration is unmatched by many newer agents.” - Infectious Disease Specialist, 15 years experience

“In ophthalmology, chloramphenicol eye drops continue to be effective for bacterial conjunctivitis when newer antibiotics fail. We monitor patients closely but find the benefit-risk ratio favorable for sight-threatening infections.” - Ophthalmologist, teaching hospital

“The hematologic monitoring requirements make chloramphenicol challenging to use in outpatient settings, but for typhoid fever in endemic areas, it remains a life-saving option where resistance patterns permit.” - Tropical Medicine Physician

“While we’ve moved to safer antibiotics for most indications, chloramphenicol’s role in treating vancomycin-resistant enterococcal infections makes it invaluable in specific clinical scenarios.” - Clinical Pharmacist, antimicrobial stewardship