Erythromycin Dosage, Side effects
Erythromycin Dosage, Side effects:
1. Overview
Erythromycin is a macrolide antibiotic used to treat various bacterial infections, including:
- Respiratory infections (e.g., pneumonia, bronchitis)
- Skin infections (e.g., acne, cellulitis)
- Sexually transmitted infections (e.g., chlamydia, syphilis)
- Ear infections (otitis media)
- Diphtheria, pertussis (whooping cough), and Legionnaires’ disease
It works by inhibiting bacterial protein synthesis, preventing bacterial growth.
2. Dosage
Dosage varies based on the infection, patient age, and formulation.
Adults (Oral/IV):
- Mild to moderate infections: 250–500 mg every 6–12 hours
- Severe infections: Up to 4 g/day in divided doses
- Acne (topical): Apply 2% gel/lotion 1–2 times daily
Children:
- 30–50 mg/kg/day in divided doses (every 6–8 hours)
Forms Available:
- Tablets/Capsules (delayed-release available)
- Oral suspension (for children)
- Topical (gels, ointments, solutions)
- Intravenous (IV) form (for severe infections)
3. Brand Names
Erythromycin is sold under various brand names worldwide, including:
- Erythrocin
- Ery-Tab (delayed-release tablets)
- Erygel (topical gel for acne)
- EryPed (pediatric suspension)
- Ilosone (older brand)
- Akne-Mycin (topical for acne)
4. Drug Interactions
Erythromycin interacts with several drugs due to its effect on CYP3A4 enzyme inhibition, increasing levels of other medications.
Major Interactions:
- Statins (e.g., simvastatin, atorvastatin) → Risk of rhabdomyolysis
- Warfarin → Increased bleeding risk
- Theophylline, Carbamazepine → Toxicity risk (seizures, arrhythmias)
- Digoxin → Increased digoxin levels (risk of toxicity)
- Colchicine → Risk of severe toxicity (muscle weakness, organ damage)
- Cisapride, Terfenadine, Astemizole → QT prolongation, fatal arrhythmias (contraindicated)
- Oral contraceptives → Possible reduced efficacy (use backup contraception)
- Protease inhibitors (e.g., ritonavir, saquinavir) → Increased erythromycin levels
Food/Alcohol Interactions:
- Grapefruit juice → May increase erythromycin absorption
- Alcohol → Can increase stomach upset
5. Side Effects
- Common: Nausea, vomiting, diarrhea, stomach pain, loss of appetite
- Serious:
- Liver toxicity (jaundice, dark urine)
- QT prolongation (irregular heartbeat)
- Hearing loss (high doses/long-term use)
- Allergic reactions (rash, anaphylaxis)
6. Contraindications
- Hypersensitivity to macrolides
- Liver disease (caution)
- Myasthenia gravis (may worsen muscle weakness)
- History of QT prolongation
Conclusion
Erythromycin is a versatile antibiotic but requires careful dosing and monitoring for drug interactions. Always consult a doctor before use, especially if taking other medications.
