Erythromycin
Mechanism :
Erythromycin is a macrolide antibiotic. It is bacteriostatic against most gram-positive and gram-negative organisms and used in the treatment of infections caused by chlamydia, mycoplasma, urea plasma, spirochetes and rickettsia. It is used as a prophylactic agent against ophthalmia neonatorum and pertussis.
Indication :
- Pertussis
- Penicillin allergic rheumatic fever prophylaxis
- Campylobacter infection
- Uncomplicated genital infections
- Yersinia pseudo tuberculosis infections
- Mycoplasma pneumonia
- GI dysmotility
Contraindications :
Contraindicated in patients with known hypersensitivity to erythromycin, or any other macrolide. Erythromycin is contraindicated in patients taking terfenadine, astemizole, or cisapride. Concurrent topical acne therapy should be used with caution as irritation can occur.
Dosing :
30-50 mg/kg/day orally in 3-4 divided doses; Max: 4 g/day for one to two weeks.
GI dysmotility:
10-20 mg/kg/day in 3-4 divided doses.
Adverse Effect :
Vomiting, nausea, diarrhea, abdominal pain, anorexia, hepatic dysfunction, ventricular arrhythmias (tachycardia, torsades de pointes, in patients with prolonged QT intervals), chest pain, dizziness, palpitations.
Interaction :
Theophylline: Increase in serum theophylline levels and potential theophylline toxicity.
Oral anticoagulants: Increased anticoagulant effects.
Benzodiazepines: Increase the pharmacologic effects.
Carbamazepine, Cyclosporine, Tacrolimus, Hexobarbital, Phenytoin, Alfentanil, Cisapride, Disopyramide, Lovastatin, Bromocriptine, Valproate, Terfenadine, and Astemizole: Increased serum levels.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 20-50 | Dose as in normal renal function |
| 10-20 | Dose as in normal renal function |
| <10 | 50–75 % of normal dose; maximum 2 g daily |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Not dialysed. Dose as in GFR<10 mL/min |
| HD | Not dialysed. Dose as in GFR<10 mL/min |
| HDF/High flux | Unknown dialysability. Dose as in GFR<10 mL/min |
| CAV/VVHD | Unknown dialysability. Dose as in normal renal function |
Hepatic Dose :
Erythromycin should be used with caution in patients with impaired hepatic function. Although specific dosage guidelines are not available, a reduced dosage may be necessary.