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erythromycin base
Apo-Erythro Base†, EMU-V Tablets‡, E-Base, E-Mycin, Erybid†, ERYC, Ery-Tab, Erythromid†, Erythromycin Base Filmtab, Erythromycin Delayed-Release, Novo-Rythro Encap†, PCE Dispertab

erythromycin estolate
Ilosone, Ilosone Pulvules, Novo-Rythro†

erythromycin ethylsuccinate
Apo-Erythro-ES†, E.E.S., EES-400‡, EES granules‡, Erymin§, EryPed, EryPed 200, EryPed 400, Erythroped§, Erythroped A§, Novo-Rythro†

erythromycin lactobionate
Erythrocin, Erythromycin Lactobionate

erythromycin stearate
Apo-Erythro-S†, Erythrocin Stearate, Novo-Rythro†

Pregnancy Risk Category B

How supplied
erythromycin base

Tablets (enteric-coated):
250 mg, 333 mg, 500 mg
Tablets (filmtabs):
250 mg, 500 mg
Capsules (delayed-release):
250 mg
erythromycin estolate

Tablets:
500 mg
Capsules:
250 mg
Oral suspension:
125 mg/5 ml, 250 mg/5 ml
erythromycin ethylsuccinate

Tablets (film-coated):
400 mg
Tablets (chewable):
200 mg
Oral suspension:
200 mg/5 ml, 400 mg/5 ml, 100 mg/2.5 ml
erythromycin lactobionate

Injection:
500-mg, 1-g vials
erythromycin stearate

Tablets (film-coated):
250 mg, 500 mg

Action
Inhibits bacterial protein synthesis by binding to the 50S subunit of the ribosome. Bacteriostatic or bactericidal, depending on concentration.

Indications & dosage
Acute pelvic inflammatory disease due to
Neisseria gonorrhoeae--
Adults:
500 mg I.V. (lactobionate) q 6 hours for 3 days; then 250 mg (base, estolate, stearate) or 400 mg (ethylsuccinate) P.O. q 6 hours for 7 days.
Children:
initially, 20 mg/kg (base, ethylsuccinate, stearate) P.O. 11/2 to 2 hours before procedure; then half the initial dose 6 hours later.
Intestinal amebiasis due to
Entamoeba histolytica--
Adults:
400 mg P.O. (ethylsuccinate) q.i.d. for 10 to 14 days. I.V. therapy not effective.
Children:
30 to 50 mg/kg (ethylsuccinate) P.O. daily, in divided doses, for 10 to 14 days. I.V. therapy not effective.
Erythrasma--

Adults:
250 mg P.O. (base, estolate, stearate) t.i.d. for 21 days.
Rheumatic fever prophylaxis--

Adults:
250 mg (base, estolate, stearate) P.O. q 12 hours.
Mild to moderately severe respiratory tract, skin, and soft-tissue infections due to sensitive group A beta-hemolytic streptococci,
Streptococcus pneumoniae, Mycoplasma pneumoniae, Corynebacterium diphtheriae, or Bordetella pertussis--
Adults:
250 to 500 mg (base, estolate, stearate) P.O. q 6 hours; or 400 to 800 mg (ethylsuccinate) P.O. q 6 hours; or 15 to 20 mg/kg I.V. daily, as continuous infusion or in divided doses q 6 hours for 10 days (3 weeks for Mycoplasma infection).
Children:
30 to 50 mg/kg (oral erythromycin salts) P.O. daily, in divided doses q 6 hours; or 15 to 20 mg/kg I.V. daily, in divided doses q 4 to 6 hours for 10 days (3 weeks for Mycoplasma infection).
Listeria monocytogenes infection--
Adults:
250 mg (base, estolate, stearate) P.O. q 6 hours or 500 mg P.O. q 12 hours.
Nongonococcal urethritis due to
Ureaplasma urealyticum--
Adults:
500 mg (base, estolate, stearate) P.O. q 6 hours for at least 7 days.
Syphilis in patients allergic to penicillin--

Adults:
500 mg (base, estolate, stearate) P.O. q.i.d. for 2 weeks.
Legionnaires' disease--

Adults:
500 mg to 1 g I.V. or P.O. (base, estolate, stearate) or 800 to 1,600 mg (ethylsuccinate) q 6 hours for 10 to 14 days.
Uncomplicated urethral, endocervical, or rectal infections due to
Chlamydia trachomatis when tetracyclines are contraindicated--
Adults:
500 mg (base, estolate, stearate) or 800 mg (ethylsuccinate) P.O. q.i.d. for 14 days.
Urogenital
C. trachomatis infections during pregnancy--
Adults:
500 mg (base, estolate, stearate) P.O. q.i.d. for at least 7 days or 250 mg (base, estolate, stearate) or 400 mg (ethylsuccinate) P.O. q.i.d. for at least 14 days.
Conjunctivitis due to
C. trachomatis in neonates--
Neonates:
50 mg/kg (base, estolate, stearate) P.O. daily in four divided doses for 14 days.
Pneumonia in infants caused by
C. trachomatis--
Infants:
50 mg/kg/day (base, estolate, stearate) P.O. in four divided doses for 21 days or 15 to 20 mg/kg/day (lactobionate) I.V. as a continuous infusion or in four divided doses.

Adverse reactions
CV:
ventricular arrhythmias.
EENT:
hearing loss (with high I.V. doses).
GI:
abdominal pain and cramping, nausea, vomiting, diarrhea.
Hepatic:
cholestatic jaundice (with erythromycin estolate).
Skin:
urticaria, rash, eczema.
Other:
overgrowth of nonsusceptible bacteria or fungi; anaphylaxis; fever; vein irritation, thrombophlebitis after I.V. injection.

Interactions
Drug-drug.
Carbamazepine: increased carbamazepine blood levels and increased risk of toxicity. Monitor closely.
Cisapride:
may increase cisapride levels, leading to toxicity including arrhythmias.
Clindamycin, lincomycin:
may be antagonistic. Don't use together.
Cyclosporine:
increased levels of cyclosporine. Monitor closely.
Digoxin:
increased serum digoxin levels. Monitor for digoxin toxicity.
Disopyramide:
increased disopyramide plasma levels resulting, in some cases, in arrhythmias and prolonged QT intervals. Monitor ECG.
Midazolam, triazolam:
increased effects of these drugs. Monitor closely.
Oral anticoagulants:
increased anticoagulant effect. Monitor PT and INR closely.
Theophylline:
decreased erythromycin blood level and increased theophylline toxicity. Use together cautiously.
Drug-herb.
Pill-bearing spurge: may inhibit CYP3A enzymes, affecting drug metabolism. Use together cautiously.

Effects on diagnostic tests
Erythromycin may interfere with fluorometric determination of urine catecholamines. AST and ALT may become falsely elevated during erythromycin therapy (rare).

Contraindications
Contraindicated in patients with hypersensitivity to drug or other macrolides. Erythromycin estolate is contraindicated in patients with hepatic disease.

Nursing considerations

I.V. administration

Patient teaching

*Liquid contains alcohol. **May contain tartrazine.  †Canada  ‡Australia  §U.K.  OTCOver the counter
Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE-THREATENING

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