Chloramphenicol

1. Oral / Systemic Use

FDA-Approved Indications:

• Serious bacterial infections caused by susceptible organisms when safer alternatives are ineffective or contraindicated:
• Typhoid fever (Salmonella Typhi)
• Meningitis caused by Haemophilus influenzae, Neisseria meningitidis, or Streptococcus pneumoniae
• Rickettsial infections (e.g., Rocky Mountain spotted fever)
• Septicemia caused by susceptible bacteria

Clinically Accepted Off-Label Uses:

• Anaerobic infections (e.g., Bacteroides species)
• Brain abscesses
• Endocarditis caused by susceptible organisms (often as combination therapy)

Special Notes:

• Oral/systemic use is reserved for serious infections due to risk of aplastic anemia and other toxicities.

2. Ophthalmic Use (Eye Drops / Ointment)

FDA-Approved Indications:

• Bacterial conjunctivitis caused by susceptible organisms, including:
• Staphylococcus aureus
• Streptococcus pneumoniae
• Haemophilus influenzae

Clinically Accepted Off-Label Uses:

• Keratitis caused by susceptible bacteria
• Prevention of neonatal conjunctivitis in certain high-risk situations (topical prophylaxis)

Special Notes:

• Topical use is generally safe and well-tolerated.
• Systemic toxicity is minimal when used ophthalmically.

রেজিস্টার্ড চিকিৎসকের নির্দেশনা অনুযায়ী ঔষধ সেবন করুন।

1. Oral / Systemic Use

Adults:

• Severe infections (typhoid, rickettsial infections, meningitis, septicemia):
• 50–100 mg/kg/day divided into 4 doses (every 6 hours).
• Maximum: 4 g per day.

Children:

• 50–75 mg/kg/day divided every 6 hours.
• Adjust dose carefully based on age, weight, and renal/hepatic function.

Special Considerations:

• Elderly or debilitated patients: Start at lower end of dose range.
• Renal or hepatic impairment: Reduce dose; monitor for toxicity.
• Duration: Usually 7–14 days, depending on infection type and clinical response.
• Monitor blood counts regularly due to risk of bone marrow suppression.

2. Ophthalmic Use (Eye Drops / Ointment)

Adults and Children:

• Bacterial conjunctivitis:
• Eye drops: 1–2 drops every 2–6 hours for 7–10 days.
• Ointment: Apply 1 cm ribbon to conjunctival sac 2–4 times daily.

Special Notes:

• Treatment may be adjusted based on severity and clinical response.
• Minimal systemic absorption, but local irritation may occur.
• Do not use if hypersensitive to sulfonamides.

রেজিস্টার্ড চিকিৎসকের নির্দেশনা অনুযায়ী ঔষধ সেবন করুন।

Chloramphenicol is a broad-spectrum bacteriostatic antibiotic that inhibits bacterial protein synthesis. It binds reversibly to the 50S subunit of bacterial ribosomes, preventing peptide bond formation by inhibiting peptidyl transferase activity. This action blocks the elongation of the polypeptide chain, thereby inhibiting bacterial growth and replication. It is effective against both aerobic and anaerobic bacteria.

• Absorption:
  Well absorbed orally with bioavailability around 70–90%.
• Distribution:
  Widely distributed in body tissues and fluids including cerebrospinal fluid (CSF), lungs, and eyes.
• Metabolism:
  Mainly metabolized in the liver by glucuronidation to inactive chloramphenicol glucuronide.
• Elimination:
  Excreted primarily by the kidneys (about 50% as metabolites) and some unchanged drug in urine.
• Half-life:
  Approximately 1.5 to 4 hours in adults; prolonged in neonates and those with liver dysfunction.

• Pregnancy:
  Category C — Animal studies have shown adverse effects; use only if clearly needed.
• Lactation:
  Excreted in breast milk; caution advised due to risk of toxicity in the infant.

• Antibiotic
• Broad-spectrum bacteriostatic agent

• Known hypersensitivity to chloramphenicol.
• History of blood dyscrasias (e.g., aplastic anemia).
• Severe hepatic impairment.
• Neonates (risk of “Gray baby syndrome”).

• Risk of aplastic anemia, which can be fatal; monitor blood counts regularly.
• Use caution in neonates due to immature liver enzyme systems leading to toxic accumulation (Gray baby syndrome).
• Potential for bone marrow suppression; reversible with dose reduction or discontinuation.
• Monitor liver and renal function during prolonged therapy.
• Avoid use in patients with pre-existing blood disorders.

Common:

• Gastrointestinal upset (nausea, vomiting, diarrhea)
• Rash and hypersensitivity reactions
• Reversible bone marrow suppression (anemia, leukopenia, thrombocytopenia)

Serious/Rare:

• Aplastic anemia (idiosyncratic and potentially fatal)
• Gray baby syndrome in neonates (cyanosis, abdominal distension, hypotension)
• Peripheral neuropathy with prolonged use
• Leukemia (rare)

• Increased risk of bone marrow toxicity with other myelosuppressive drugs.
• May inhibit hepatic enzymes leading to elevated levels of drugs metabolized by glucuronidation (e.g., phenytoin).
• Concomitant use with enzyme inducers (e.g., rifampin) may reduce chloramphenicol levels.
• Avoid alcohol during therapy due to risk of increased toxicity.

• Use restricted to serious infections when safer alternatives are not effective or contraindicated.
• Emphasis on regular hematologic monitoring due to risk of severe bone marrow toxicity.
• Guidelines recommend caution or avoidance in neonates and breastfeeding mothers.
• FDA and other authorities maintain warnings about aplastic anemia risk and gray baby syndrome.

• Store at 20°C to 25°C (68°F to 77°F).
• Protect from light and moisture.
• Keep container tightly closed.
• For injectable form, follow manufacturer instructions for storage and handling.