1. Introduction
Chloramphenicol is a broad-spectrum antibiotic used to treat serious bacterial infections. It is available in various forms, including eye drops, ointments, and oral formulations. While it is highly effective against a wide range of bacteria, its use is limited due to potential serious side effects, such as bone marrow suppression.
2. Indications
- Approved Indications:
- Bacterial conjunctivitis (eye drops and ointments).
- Life-threatening infections caused by susceptible organisms, such as:
- Typhoid and paratyphoid fever.
- Meningitis (when no alternative is available).
- Rickettsial infections.
- Brain abscesses.
- Topical treatment of bacterial skin infections.
- Off-Label Uses:
- Severe infections in patients with allergies to first-line antibiotics.
3. Dosage
- For Bacterial Conjunctivitis:
- Eye drops: 1 drop in the affected eye(s) every 2 hours while awake, reducing frequency as symptoms improve.
- Eye ointment: Apply a small amount (1 cm ribbon) to the lower eyelid 3–4 times daily.
- For Systemic Infections (Oral or IV):
- Adults: 50–100 mg/kg/day in divided doses every 6 hours.
- Children: 50–75 mg/kg/day in divided doses every 6 hours.
- Maximum dose: 4 g/day.
- For Neonates:
- Initial dose: 25 mg/kg/day in divided doses every 6 hours (reduce dose in premature infants due to slower metabolism).
4. Administration
- Eye Drops and Ointments:
- Wash hands before and after application.
- Avoid touching the dropper tip or tube to any surface, including the eye.
- Oral or IV Formulations:
- Administer orally with or without food.
- For IV administration, dilute according to guidelines and administer slowly.
5. Forms Available
- Eye drops: 0.5% solution.
- Eye ointment: 1% concentration.
- Oral capsules: 250 mg.
- Injectable solution: 1 g/vial.
6. Side Effects
6.1. Common Side Effects
- Eye irritation (eye drops/ointment).
- Nausea and vomiting (oral or IV).
- Diarrhoea.
6.2. Less Common Side Effects
- Headache.
- Dizziness.
6.3. Rare but Serious Side Effects
- Bone marrow suppression (aplastic anaemia).
- Grey baby syndrome (in neonates due to immature metabolism).
- Peripheral neuropathy.
7. Warnings
- Chloramphenicol can cause serious and potentially fatal blood disorders, including aplastic anaemia and pancytopenia. Use only when no safer alternatives are available.
- Contraindicated in individuals with a history of hypersensitivity to chloramphenicol or related compounds.
- Avoid long-term or repeated use due to the risk of cumulative toxicity.
8. Precautions
- Perform baseline and periodic complete blood counts (CBC) during prolonged use to detect early signs of bone marrow suppression.
- Use with caution in patients with liver or kidney dysfunction, as drug clearance may be reduced.
- Avoid unnecessary use to minimise the risk of antibiotic resistance.
9. Interactions
- Drug-Drug Interactions:
- Anticoagulants (e.g., warfarin): Enhanced anticoagulant effect.
- Phenytoin and phenobarbital: Reduced metabolism, increasing their toxicity risk.
- Rifampin: May reduce chloramphenicol efficacy.
- Drug-Food Interactions:
- No significant interactions.
10. Monitoring Parameters
- Complete blood count (CBC) during prolonged or high-dose therapy.
- Serum drug levels, especially in neonates or patients with liver or renal impairment.
- Watch for symptoms of toxicity, such as pallor, fatigue, or easy bruising (signs of bone marrow suppression).
11. Use in Children
- Approved for use in bacterial infections but with extreme caution due to the risk of grey baby syndrome in neonates.
- Dose adjustments are required based on age and weight.
12. Use in Pregnancy
- Category C: Use only if the potential benefit outweighs the risk.
- Avoid use during late pregnancy as it may cause neonatal complications, including grey baby syndrome.
13. Use in Elderly
- Use with caution, particularly in those with liver or kidney dysfunction. Monitor for cumulative toxicity.
14. Use in Kidney Disease
- Dose adjustment may be required in severe renal impairment due to reduced clearance.
15. Use in Liver Disease
- Use cautiously in patients with liver disease, as metabolism and clearance of chloramphenicol may be impaired.
16. Patient Counselling Points
- For eye infections, use the drops or ointment as prescribed. Do not share with others to prevent cross-infection.
- Complete the full course of treatment, even if symptoms improve early.
- Report any signs of severe side effects, such as bruising, fatigue, or unusual bleeding, immediately.
- Avoid unnecessary use or prolonged treatment to minimise serious side effects.
- For systemic use, regular blood tests may be required to monitor for toxicity.
17. Table of Brand Names, Manufacturers, and Prices
Brand Name | Manufacturer | Price (USD) |
---|---|---|
Chloromycetin | Pfizer | $15–25 (10 mL, 0.5% eye drops) |
Optrex | Reckitt Benckiser | $10–20 (10 mL, 0.5% eye drops) |
Generic Options | Various | $5–10 (10 mL, 0.5% eye drops) |
18. FAQs (15 Questions)
- What is chloramphenicol used for?
It is used to treat bacterial eye infections (conjunctivitis), life-threatening infections like meningitis, and infections caused by susceptible organisms. - How does chloramphenicol work?
It inhibits bacterial protein synthesis, preventing bacterial growth. - Can chloramphenicol cause side effects?
Yes, common side effects include nausea, vomiting, and eye irritation. Serious side effects include bone marrow suppression and grey baby syndrome. - How is chloramphenicol applied to the eyes?
Use 1 drop every 2 hours for eye drops or apply a small amount of ointment to the lower eyelid 3–4 times daily. - Is chloramphenicol safe for children?
Yes, but it must be used with caution in neonates due to the risk of grey baby syndrome. - Can pregnant women use chloramphenicol?
It should be avoided unless the potential benefits outweigh the risks. - Can chloramphenicol be used for viral infections?
No, it is ineffective against viral infections. - What should I do if I miss a dose?
Take it as soon as you remember, but skip it if it’s close to the next dose. - Can chloramphenicol cause anaemia?
Yes, it can cause aplastic anaemia, a rare but serious side effect. - Does chloramphenicol interact with other medications?
Yes, it interacts with anticoagulants, phenytoin, and rifampin, among others. - How long does it take for chloramphenicol eye drops to work?
Improvement is usually seen within 48 hours. - Can I wear contact lenses while using chloramphenicol?
No, avoid wearing contact lenses during treatment. - How should chloramphenicol eye drops be stored?
Store in the refrigerator and discard after 28 days of opening. - Can chloramphenicol treat ear infections?
It may be prescribed off-label for ear infections in specific cases. - How long can chloramphenicol be used?
It is typically used for a short duration (e.g., 5–7 days). Prolonged use is avoided due to toxicity risks.