Usage
This combination is primarily used for eye infections where bacterial infection is present along with inflammation. It combines an antibiotic (chloramphenicol), a corticosteroid (dexamethasone), and another antibiotic specifically targeting gram-negative bacteria (polymyxin B).
- Pharmacological Classification: Antibiotic (Chloramphenicol and Polymyxin B), Corticosteroid (Dexamethasone)
- Mechanism of Action: Chloramphenicol inhibits bacterial protein synthesis, Polymyxin B disrupts the bacterial cell membrane, and Dexamethasone reduces inflammation.
Alternate Names
This combination medication may not have a specific international non-proprietary name (INN). It is typically identified by the constituent drugs. Brand names vary depending on the manufacturer and region.
How It Works
- Pharmacodynamics: Chloramphenicol exerts a bacteriostatic effect by binding to the 50S subunit of the bacterial ribosome, inhibiting protein synthesis. Polymyxin B binds to the lipopolysaccharide in the outer membrane of gram-negative bacteria, leading to increased permeability and cell death. Dexamethasone, a glucocorticoid, suppresses inflammation by inhibiting multiple inflammatory pathways.
- Pharmacokinetics:
- Chloramphenicol: Well-absorbed orally. Metabolized in the liver, primarily by glucuronidation. Excreted in urine.
- Dexamethasone: Well-absorbed orally. Metabolized in the liver. Excreted in urine.
- Polymyxin B: Poorly absorbed orally; administered topically for eye infections. Primarily excreted renally when administered systemically.
- Elimination Pathways: Chloramphenicol and Dexamethasone primarily undergo hepatic metabolism and renal excretion. Polymyxin B is primarily renally excreted.
Dosage
Standard Dosage
This medication is generally for topical ophthalmic use. Systemic administration of this combination is rare.
Adults:
Instill 1-2 drops in the affected eye(s) every 3-4 hours, or as directed by a physician.
Children:
Dosage should be determined by a physician. Generally, the same dosage as for adults can be used for older children.
Special Cases:
Dosage adjustments for elderly patients, those with renal/hepatic impairment, and those with comorbid conditions should be determined by a physician, and are usually not necessary for ophthalmic use.
Clinical Use Cases
The provided sources do not list clinical use cases for intubation, surgical procedures, mechanical ventilation, ICU use, and emergency situations. The clinical use case is mainly for treating bacterial eye infections with inflammation.
Dosage Adjustments
Dosage adjustments are based on the severity of the infection and patient response.
Side Effects
Common Side Effects
- Eye irritation
- Burning sensation
- Stinging
- Blurred vision
Rare but Serious Side Effects
- Allergic reactions
- Increased intraocular pressure
- Secondary infections
Long-Term Effects
Long-term use of corticosteroids like dexamethasone in the eye can lead to glaucoma, cataracts, and increased risk of infection.
Adverse Drug Reactions (ADR)
Severe allergic reactions, although rare, warrant immediate medical attention.
Contraindications
- Hypersensitivity to any component of the medication.
- Viral, fungal, or mycobacterial eye infections (except under close supervision for mixed infections).
- Use with caution in patients with glaucoma or a history of herpes simplex keratitis.
Drug Interactions
- Other ophthalmic medications: Consult a physician before using other eye drops concomitantly.
Pregnancy and Breastfeeding
Consult a physician before use during pregnancy or breastfeeding. Topical application minimizes systemic exposure, but safety has not been definitively established.
Drug Profile Summary
- Mechanism of Action: Chloramphenicol: Bacterial protein synthesis inhibitor; Polymyxin B: Bacterial cell membrane disruptor; Dexamethasone: Anti-inflammatory.
- Side Effects: Eye irritation, burning, stinging, blurred vision. Rarely: allergic reactions, increased intraocular pressure, secondary infections.
- Contraindications: Hypersensitivity, certain eye infections, glaucoma, history of herpes simplex keratitis.
- Drug Interactions: Consult a physician regarding concomitant use of other ophthalmic medications.
- Pregnancy & Breastfeeding: Consult a physician before use.
- Dosage: 1-2 drops in the affected eye every 3-4 hours.
- Monitoring Parameters: Intraocular pressure, signs of infection, allergic reactions.
Popular Combinations
Not applicable for ophthalmic use.
Precautions
- General Precautions: Proper hand hygiene before administration. Avoid touching the tip of the bottle to the eye.
- Specific Populations: Use cautiously in pregnant/breastfeeding women, children, and the elderly. Monitor for adverse effects.
FAQs
Q1: What is the recommended dosage for Chloramphenicol + Dexamethasone + Polymyxin B eye drops?
A: The usual dose is 1-2 drops in the affected eye every 3-4 hours. However, the dosage may vary depending on the severity of the infection and should be determined by a physician.
Q2: What are the common side effects?
A: Common side effects include temporary eye irritation, burning, stinging, and blurred vision.
Q3: Can this combination be used in children?
A: Yes, but the dosage should be determined by a physician.
Q4: Can pregnant or breastfeeding women use this combination?
A: They should consult a physician before use.
Q5: Are there any serious side effects?
A: While rare, serious side effects can include allergic reactions, increased intraocular pressure, and secondary infections.
Q6: What should I do if I experience side effects?
A: Discontinue use and consult a physician.
Q7: Can I use other eye drops along with this combination?
A: Consult a physician before using other eye drops concomitantly.
Q8: What if I miss a dose?
A: Instill the missed dose as soon as you remember, then continue with your regular dosing schedule. Do not double the dose.
Q9: How long should I use these eye drops?
A: Use as directed by the physician. Do not discontinue use prematurely even if symptoms improve, unless directed by the physician.
Q10: How should I store this medication?
A: Store as directed on the product packaging.
