Erythromycin
Indications
Erythromycin is used for:
Susceptible infections, Respiratory tract infections, Enteritis, Pertussis, Trench fever, Chanroid, Chlamydial infections, Diphtheria, Legionnaire's disease, Pneumonia, Sinusitis, Bronchitis, Acne, Rheumatic fever, Neonatal conjunctivitis.
Adult Dose
Adults: Usually 250 mg every 6 hours, or 500 mg every 12 hours. May increase up to 4 g/day, according to severity of infection.
Upper respiratory tract infections of mild to moderate severity: 250 to 500 mg 4 times a day for 10 days.
Lower respiratory infections of mild to moderate severity: 250 to 500 mg 4 times a day for 10 days.
Respiratory tract infections due to Mycoplasma pneumoniae: 500 mg 6 hours for 5 to 10 days, treat severe infections for up to 3 weeks.
Skin and soft tissue infections of mild to moderate severity: 250 to 500 mg 4 times a day for 10 days.
Pelvic inflammatory diseases (PID), acute due to Neisseria gonorrhoeae: 500 mg 4 times a day for 10 to 14 days.
Urogenital infection during pregnancy caused by Chlamydia trachomatis: 500 mg 4 times daily for 7 days or
250 mg 4 times daily for 14 days.
Urethral, endocervical or rectal infections, uncomplicated: 500 mg 4 times daily for 7 days or
250 mg 4 times daily for 14 days.
Non-gonococcal urethritis: 500 mg 4 times daily for at least 7 days.
Neisseria gonorrhoeae: Uncomplicated urethral, endocervical or rectal infections and in penicillinase producing N. gonorrhoeae(PPNG): 500 mg 4 times a day for 7 days.
Early syphillis (primary, secondary or latent syphillis of < 1 year duration): 500 mg 4 times a day for 14 days.
Severe or chronic diarrhoea: 500 mg 4 times a day for 7 days. Rheumatic fever: 250 mg 2 times daily.
Bacterial endocarditis: 1 g 2 hours prior to procedures, then 500 mg 6 hours after initial dose.
Acne: 500 mg twice daily for 3 months reduced to 250 mg twice for 3 months.
Hepatic Impairment
Use caution
Child Dose
Children:
PO 50 mg/kg/day q6–8h
Renal Dose
Renal Impairment
Dose adjustment not necessary
Administration
Should be taken on an empty stomach. Best taken on an empty stomach at least ½ hr & preferably 2 hr before meals.
Reconstitution: Oral susp: Add 77 mL of water and shake vigorously. This makes 100 mL susp.
Contra Indications
Hypersensitivity; porphyria; hepatic impairment; pregnancy.
Precautions
Increased risk of cholestatic hepatitis when treatment is >10 days or in patients with previous history of erythromycin usage. History of hepatic disorders; arrhythmias; prolonged QT interval; lactation. Monitor liver function. Avoid estolate in liver impairment. Caution when using lactobionate in patients with severe renal impairment. May aggravate muscle weakness in patients with myasthenia gravis.
Lactation: distributed in breast milk, use with caution; AAP categorizes as compatible with breastfeeding
Pregnancy-Lactation
Interactions
May decrease plasma levels of valproic acid thus, increasing the risk of seizures. Increased plasma concentrations w/ probenecid.
Adverse Effects
Side effects of Erythromycin :
1-10%
Abdominal pain (8%),Headache (8%),Nausea (8%),Diarrhea (7%),Rash (3%),Vomiting (3%),Dyspepsia (2%),Flatulence (2%),Pain (2%),Pruritus (1%),Pseudomembranous colitis
Hypertrophic pyloric stenosis,Anaphylaxis,Fever,Mild allergic reactions,Urticaria,Skin eruptions,Tinnitus
<1%
Cholestatic hepatitis,Confusion,Hallucinations,Hearing loss,Hypotension,Nervous system effects including seizures,Torsade de pointes,Ventricular tachycardia,Vertigo
Potentially Fatal: Hepatotoxicity, cholestatic jaundice; raised serum transaminases; eosinophilia.
Mechanism of Action
Erythromycin inhibits protein synthesis by irreversibly binding to the 50S ribosomal subunit thus blocking the transpeptidation or translocation reactions of susceptible organisms resulting in stunted cell growth.