Drug class: Erythromycins
VA class: AM200
CAS number: 41342-53-4

Medically reviewed by Drugs.com on Dec 22, 2023. Written by ASHP.

Introduction

Erythromycin ethylsuccinate is a macrolide antibiotic.

Erythromycin Ethylsuccinate Dosage and Administration

Administration

Erythromycin ethylsuccinate is administered orally. Erythromycin ethylsuccinate oral suspensions,^{115 119} chewable tablets,¹¹⁹ and film-coated tablets¹¹⁵ may be administered without regard to meals. Chewable tablets should not be swallowed whole.

The fixed-combination preparation containing erythromycin ethylsuccinate and sulfisoxazole acetyl is administered orally and may be given without regard to meals.¹²⁰ Because the fixed-combination preparation contains a sulfonamide, the preparation should not be used in infants younger than 2 months of age, pregnant women at term, or mothers who are nursing infants younger than 2 months of age.¹²⁰

Dosage

Dosage of erythromycin ethylsuccinate is expressed in terms of erythromycin. Since the ethylsuccinate has different absorption characteristics in adults than do other commercially available forms of erythromycin, higher oral doses are needed to achieve therapeutic effects. The manufacturer states that, for adults, 400 mg of erythromycin as the ethylsuccinate provides erythromycin activity similar to that provided by 250 mg of erythromycin as the base, stearate, or estolate.^{115 119}

The usual adult oral dosage of erythromycin as the ethylsuccinate is 400 mg every 6 hours.^{115 119} In severe infections, dosage may be increased up to 4 g daily.^{115 119} The usual oral dosage of erythromycin as the ethylsuccinate in children is 30–50 mg/kg daily in 4 equally divided doses every 6 hours.^{115 119} For more severe infections, this dosage may be doubled.^{115 119} An alternative pediatric dosage of 0.9–3 g/m² daily in 4 equally divided doses has been recommended. The manufacturer states that adults and children may receive one-half the total daily dose of erythromycin ethylsuccinate every 12 hours as an alternative dosage schedule,¹¹⁵ but some clinicians believe this schedule is inadequate for all but minor infections caused by highly susceptible organisms. The manufacturer also states that adults and children may receive one-third the total daily dose every 8 hours as an alternative dosage schedule.¹¹⁵

Pharyngitis and Tonsillitis

If erythromycin ethylsuccinate is used for the treatment of pharyngitis and tonsillitis caused by Streptococcus pyogenes (group A β-hemolytic streptococci), the usual dosage is 40 mg/kg daily given in 2–4 divided doses for 10 days.¹⁰²

Prophylaxis of Recurrent Rheumatic Fever

For continuous prophylaxis to prevent recurrences in patients with a history of rheumatic heart disease, the manufacturer recommends oral erythromycin as the ethylsuccinate in a dosage of 400 mg twice daily.^{115 119}

When selecting anti-infectives for prophylaxis of recurrent rheumatic fever, the current recommendations published by the American Heart Association (AHA) should be consulted.¹⁰⁴

Prevention of Bacterial Endocarditis

Because of adverse GI effects and the complicated pharmacokinetics of the various erythromycin formulations, current recommendations of the AHA for prevention of bacterial endocarditis no longer include erythromycins as alternatives to penicillins in penicillin-allergic patients.¹¹⁶ However, the AHA states that clinicians who have successfully used an erythromycin for prophylaxis in individual patients may choose to continue using these agents.¹¹⁶ If erythromycin ethylsuccinate is used for prophylaxis of bacterial endocarditis in penicillin-allergic patients at risk who are undergoing certain dental or upper respiratory tract procedures, the AHA recommends that adults receive 800 mg of erythromycin as the ethylsuccinate 2 hours before the procedure and 400 mg 6 hours later and that children receive 20 mg/kg 2 hours before the procedure and 10 mg/kg 6 hours later.¹¹¹ Pediatric dosage should not exceed adult dosage.¹¹¹

When selecting anti-infectives for prophylaxis of bacterial endocarditis, the current recommendations published by the AHA should be consulted.¹¹⁶

Syphilis

Although penicillin G is the drug of choice for all stages of syphilis,^{100 101 102} the manufacturer states that erythromycin as the ethylsuccinate may be given orally in a dosage of 48–64 g over 10–15 days for the treatment of primary syphilis in adults.¹¹⁵ Erythromycin is no longer included in US Centers for Disease Control and Prevention (CDC) recommendations for the treatment of any form of syphilis in adults or adolescents (including primary, secondary, latent, or tertiary or neurosyphilis) and is not recommended for the treatment of congenital syphilis or syphilis in older infants and children.¹⁰¹ In addition, erythromycin is no longer recommended by the CDC or American Academy of Pediatrics (AAP) for the treatment of syphilis in pregnant women who are hypersensitive to penicillin since numerous treatment failures (including in the fetus) have been reported with the drug.^{101 102}

Gonorrhea and Associated Infections

The AAP currently recommends that all children beyond the neonatal period being treated for uncomplicated vulvovaginal, urethral, or pharyngeal gonorrhea, epididymitis, proctitis, or disseminated gonococcal infections, including meningitis or endocarditis, receive presumptive treatment for possible coexisting chlamydial infections.¹⁰² If oral erythromycin is used for presumptive treatment of chlamydial infection in children who weigh less than 45 kg, the AAP recommends a dosage of 50 mg/kg daily (maximum 2 g daily) given in 4 divided doses for 7 days.¹⁰²

Nongonococcal Urethritis

When oral erythromycin ethylsuccinate is used as an alternative to azithromycin or doxycycline for the treatment of nongonococcal urethritis, the CDC and manufacturer recommend a regimen of 800 mg of erythromycin 4 times daily for 7 days.^{100 101 115 119}

Patients with recurrent and persistent urethritis who were not compliant with the full course of erythromycin therapy or who were reexposed to untreated sexual partner(s) should receive a second course of oral erythromycin.¹⁰¹ If the patient has recurrent and persistent urethritis, was compliant with the regimen, and reexposure can be excluded, the CDC recommends that oral erythromycin ethylsuccinate be given in regimen of 800 mg of erythromycin 4 times daily for 7 days in conjunction with a single 2-g dose of oral metronidazole.¹⁰¹

Chlamydial Infections

For the treatment of uncomplicated urethral, endocervical, or rectal infections caused by Chlamydia trachomatis in nonpregnant adults or adolescents when azithromycin or tetracyclines cannot be used, the CDC and others recommend oral erythromycin as the ethylsuccinate in a dosage 800 mg 4 times daily for 7 days.^{100 101} The dosage of erythromycin as the ethylsuccinate recommended by the CDC for the treatment of these infections in children weighing 45 kg or less is 50 mg/kg daily given in 4 divided doses for 14 days.¹⁰¹

For the treatment of chlamydial urogenital infections during pregnancy, the recommended dosage of oral erythromycin as the ethylsuccinate is 800 mg 4 times daily for 7 days;^{100 101} for women who cannot tolerate this regimen, a dosage of oral erythromycin as the ethylsuccinate of 400 mg 4 times daily for 14 days may be used.¹⁰¹

For the treatment of pneumonia caused by C. trachomatis or ophthalmia neonatorum caused by C. trachomatis in infants, the recommended dosage of oral erythromycin is 50 mg/kg daily given in 4 divided doses for 14 days;^{100 101} follow-up is recommended and a second course of therapy may be necessary.¹⁰¹

For the treatment of trachoma in children, oral erythromycin has been given for 40 days in conjunction with topical anti-infective therapy; however, optimum therapy has not been established, and treatment may be difficult.¹⁰²

Intestinal Amebiasis

Although erythromycin is not considered a drug of choice for the treatment of intestinal amebiasis caused by Entamoeba histolytica,¹⁰² the manufacturer states that adults may receive 400 mg of erythromycin as the ethylsuccinate orally 4 times daily for 10–14 days, and children may be given 30–50 mg/kg daily in divided doses for 10–14 days.^{115 119}

Pertussis

Although the optimum dosage and duration of erythromycin for the treatment of pertussis or prevention in susceptible contacts have not been established, a dosage of 1 g daily in adults and 40–50 mg/kg daily (maximum 2 g daily) in children given in divided doses for 14 days usually is recommended.^{102 105 106 107 108 109 110} While a shorter duration of erythromycin therapy (e.g., 7 or 10 days) may be effective in some patients, ^{102 113} prophylaxis failures and bacteriologic relapse of pertussis have been reported with erythromycin regimens shorter than 14 days.^{105 106 107 108 109 110 113} Therefore, the CDC,¹⁰³ US Public Health Service Advisory Committee on Immunization Practices (ACIP),¹¹⁴ AAP,¹⁰² and some clinicians^{105 106 108 109 110} recommend that a 14-day course of erythromycin therapy be used for treatment or prevention of pertussis.

Although data from controlled studies are lacking, the CDC recommends that all household and other close contacts of individuals with pertussis receive a 14-day regimen of prophylaxis (regardless of age and vaccination status) since this may prevent or minimize transmission of the disease.¹⁰³ In addition, all close contacts younger than 7 years of age who are not fully immunized against pertussis should receive the remaining required doses of a preparation containing pertussis vaccine (using minimal intervals between doses) and those who are fully immunized but have not received a vaccine dose within the last 3 years should receive a booster dose of a pertussis vaccine preparation.¹⁰³

Legionnaires’ Disease

Although the optimum dosage and duration of erythromycin for the treatment of Legionnaires’ disease have not been established, dosages of erythromycin as the ethylsuccinate of 1.6–4 g daily in divided doses have been given alone or in combination with rifampin.^{102 115 117 118} A parenteral regimen usually is necessary for the initial treatment of severe Legionnaires’ disease and the addition of rifampin is recommended during the first 3–5 days of therapy in severely ill and/or immunocompromised patients; after a response is obtained, rifampin can be discontinued and therapy changed to oral erythromycin.^{102 117 118} The duration of therapy in patients with Legionnaires’s disease usually is 10–21 days;^{102 117 118} some clinicians recommend 14 days of therapy for patients with mild disease and 21 days for those who are immunocompromised or have severe disease. ¹⁰²

Acute Otitis Media

For the treatment of acute otitis media caused by susceptible strains of Haemophilus influenzae in children 2 months of age or older, a commercially available fixed-combination preparation containing erythromycin ethylsuccinate and sulfisoxazole acetyl is used.¹²⁰ Dosage of the combination preparation may be expressed in terms of erythromycin or sulfisoxazole.¹²⁰ The usual oral dosage for children 2 months of age or older expressed in terms of erythromycin is 12.5 mg/kg every 6 hours or 17 mg/kg every 8 hours and the usual dosage expressed in terms of sulfisoxazole is 37.5 mg/kg every 6 hours or 50 mg/kg every 8 hours (not to exceed a total daily dose of 6 g).¹²⁰ Alternatively, the following approximate dosages, expressed in terms of volumes of erythromycin ethylsuccinate and sulfisoxazole acetyl suspension (200 mg of erythromycin per 5 mL), can be used:

When the fixed-combination preparation is used, the precautions and contraindications of sulfonamides must also be considered.¹²⁰ Erythromycin ethylsuccinate and sulfisoxazole acetyl suspension should not be administered to children younger than 2 months of age.¹²⁰

Related/similar drugs

prednisone, amoxicillin, doxycycline, cephalexin, ciprofloxacin, azithromycin, metronidazole

Chemistry and Stability

Chemistry

Erythromycin ethylsuccinate occurs as a white or slightly yellow, odorless or practically odorless, practically tasteless, crystalline powder. The drug is very slightly soluble in water, freely soluble in alcohol, and soluble in polyethylene glycol.

Stability

Erythromycin ethylsuccinate chewable tablets¹¹⁹ and film-coated tablets¹¹⁵ should be stored at less than 30°C. The manufacturer of E.E.S. Liquid recommends that these oral suspensions be stored at 2–8°C until dispensed to preserve taste; once dispensed, these suspensions are stable for 14 days at room temperature.¹¹⁵ Prior to reconstitution, E.E.S granules for oral suspension should be stored at less than 30°C; after reconstitution, the oral suspension should be refrigerated and used within 10 days.¹¹⁵ The manufacturer of EryPed for oral suspension states that this preparation should be stored at less than 30°C prior to reconstitution; after reconstitution, this oral suspension should be stored at less than 25°C and is stable for 35 days at room temperature.¹¹⁹ Commercially available suspensions of erythromycin ethylsuccinate have expiration dates of 18 months following the dates of manufacture; commercially available erythromycin ethylsuccinate tablets and powder for oral suspension have expiration dates of 2 years following the dates of manufacture.

The commercially available fixed-combination preparation containing erythromycin ethylsuccinate and sulfisoxazole acetyl should be stored at less than 30°C prior to reconstitution; after reconstitution, the oral suspension should be refrigerated and unused portions discarded after 14 days.¹²⁰

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

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