Erythromycin Ethylsuccinate

Erythromycin, USP is produced by a strain of Saccharopolyspora erythraea (formerly Streptomyces erythraeus) and belongs to the macrolide group of antibiotics. It is basic and readily forms salts with acids. The base, the stearate salt, and the esters are poorly soluble in water. Erythromycin ethylsuccinate, USP is an ester of erythromycin, USP suitable for oral administration. Erythromycin ethylsuccinate, USP is known chemically as erythromycin 2′-(ethyl succinate). The molecular formula is C₄₃H₇₅NO₁₆ and the molecular weight is 862.06. The structural formula is:

Erythromycin ethylsuccinate for oral suspension, USP, 200 mg/5 mL when reconstituted with water, forms a suspension containing erythromycin ethylsuccinate, USP equivalent to 200 mg erythromycin, USP per 5 mL (teaspoonful) or 100 mg per 2.5 mL (dropperful) with an appealing fruit flavor. Erythromycin ethylsuccinate for oral suspension, USP, 400 mg/5 mL when reconstituted with water, forms a suspension containing erythromycin ethylsuccinate, USP equivalent to 400 mg of erythromycin, USP per 5 mL (teaspoonful) with an appealing banana flavor.

These products are intended primarily for pediatric use but can also be used in adults.

Inactive Ingredients

Erythromycin ethylsuccinate for oral suspension, USP, 200 mg/5 mL contains caramel flavor, mixed fruit flavor, polysorbate 80, sodium citrate dihydrate, sucrose, and xanthan gum. Erythromycin ethylsuccinate for oral suspension, USP 400 mg/5 mL contains banana flavor, caramel flavor, polysorbate 80, sodium citrate dihydrate, sucrose, and xanthan gum.

Orally administered erythromycin ethylsuccinate suspension is readily and reliably absorbed under both fasting and nonfasting conditions.

Erythromycin diffuses readily into most body fluids. Only low concentrations are normally achieved in the spinal fluid, but passage of the drug across the blood-brain barrier increases in meningitis. In the presence of normal hepatic function, erythromycin is concentrated in the liver and excreted in the bile; the effect of hepatic dysfunction on excretion of erythromycin by the liver into the bile is not known. Less than 5 percent of the orally administered dose of erythromycin is excreted in active form in the urine.

Erythromycin crosses the placental barrier, but fetal plasma levels are low. The drug is excreted in human milk.

Microbiology:

Erythromycin acts by inhibition of protein synthesis by binding 50 S ribosomal subunits of susceptible organisms. It does not affect nucleic acid synthesis. Antagonism has been demonstrated in vitro between erythromycin and clindamycin, lincomycin, and chloramphenicol.

Many strains of Haemophilus influenza are resistant to erythromycin alone but are susceptible to erythromycin and sulfonamides used concomitantly.

Staphylococci resistant to erythromycin may emerge during a course of therapy.

Erythromycin has been shown to be active against most strains of the following microorganisms, both in vitro and in clinical infections as described in the INDICATIONS AND USAGE section.

Gram-positive Organisms:

            Corynebacterium diphtheriae

            Corynebacterium minutissimum

            Listeria monocytogenes

            Staphylococcus aureus (resistant organisms may emerge during treatment)

            Streptococcus pneumoniae

            Streptococcus pyogenes

Gram-negative Organisms:

            Bordetella pertussis

            Legionella pneumophila

            Neisseria gonorrhoeae

Other Microorganisms:

            Chlamydia trachomatis

            Entamoeba histolytica

            Mycoplasma pneumoniae

            Treponema pallidum

            Ureaplasma urealyticum

            The following in vitro data are available.

            Erythromycin exhibits in vitro minimal inhibitory concentrations (MIC's) of 0.5 mcg/mL or less     against most (≥ 90%) strains of the following microorganisms; however, the safety and effectiveness of   erythromycin in treating clinical infections due to these microorganisms have not been established in adequate and well-controlled clinical trials.

Gram-positive Organisms:

            Viridans group streptococci

Gram-negative Organisms:

            Moraxella catarrhalis

Susceptibility Tests:

For specific information regarding susceptibility test interpretive criteria and associated test methods and quality control standards recognized by FDA for this drug, please see: www.fda.gov/STIC.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of erythromycin ethylsuccinate for oral suspension and other antibacterial drugs, erythromycin ethylsuccinate for oral suspension should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

Erythromycin ethylsuccinate for oral suspension is indicated in the treatment of infections caused by susceptible strains of the designated organisms in the diseases listed below:

Upper respiratory tract infections of mild to moderate degree caused by Streptococcus pyogenes, Streptococcus pneumoniae, or Haemophilus influenzae (when used concomitantly with adequate doses of sulfonamides, since many strains of H. influenzae are not susceptible to the erythromycin concentrations ordinarily achieved). (See appropriate sulfonamide labeling for prescribing information.)

Lower-respiratory tract infections of mild to moderate severity caused by Streptococcus pneumoniae or Streptococcus pyogenes.

Listeriosis caused by Listeria monocytogenes.

Pertussis (whooping cough) caused by Bordetella pertussis. Erythromycin is effective in eliminating the organism from the nasopharynx of infected individuals rendering them noninfectious. Some clinical studies suggest that erythromycin may be helpful in the prophylaxis of pertussis in exposed susceptible individuals.

Respiratory tract infections due to Mycoplasma pneumoniae.

Skin and skin structure infections of mild to moderate severity caused by Streptococcus pyogenes or Staphylococcus aureus (resistant staphylococci may emerge during treatment).

Diphtheria: Infections due to Corynebacterium diphtheriae, as an adjunct to antitoxin, to prevent establishment of carriers and to eradicate the organism in carriers.

Erythrasma: In the treatment of infections due to Corynebacterium minutissimum.

Intestinal amebiasis caused by Entamoeba histolytica (oral erythromycins only). Extraenteric amebiasis requires treatment with other agents.

Acute Pelvic Inflammatory Disease Caused by Neisseria gonorrhoeae: As an alternative drug in treatment of acute pelvic inflammatory disease caused by N. gonorrhoeae in female patients with a history of sensitivity to penicillin. Patients should have a serologic test for syphilis before receiving erythromycin as treatment of gonorrhea and a follow-up serologic test for syphilis after 3 months.

Syphilis Caused by Treponema pallidum: Erythromycin is an alternate choice of treatment for primary syphilis in penicillin-allergic patients. In primary syphilis, spinal fluid examinations should be done before treatment and as part of follow-up after therapy.

Erythromycins are indicated for the treatment of the following infections caused by Chlamydia trachomatis: Conjunctivitis of the newborn, pneumonia of infancy, and urogenital infections during pregnancy. When tetracyclines are contraindicated or not tolerated, erythromycin is indicated for the treatment of uncomplicated urethral, endocervical, or rectal infections in adults due to Chlamydia trachomatis.

When tetracyclines are contraindicated or not tolerated, erythromycin is indicated for the treatment of nongonococcal urethritis caused by Ureaplasma urealyticum.

Legionnaires' Disease caused by Legionella pneumophila. Although no controlled clinical efficacy studies have been conducted, in vitro and limited preliminary clinical data suggest that erythromycin may be effective in treating Legionnaires' Disease.

Prophylaxis:

Prevention of Initial Attacks of Rheumatic Fever:

Penicillin is considered by the American Heart Association to be the drug of choice in the prevention of initial attacks of rheumatic fever (treatment of Streptococcus pyogenes infections of the upper respiratory tract, e.g., tonsillitis or pharyngitis). Erythromycin is indicated for the treatment of penicillin-allergic patients.⁴ The therapeutic dose should be administered for 10 days.

Prevention of Recurrent Attacks of Rheumatic Fever:

Penicillin or sulfonamides are considered by the American Heart Association to be the drugs of choice in the prevention of recurrent attacks of rheumatic fever. In patients who are allergic to penicillin and sulfonamides, oral erythromycin is recommended by the American Heart Association in the long-term prophylaxis of Streptococcal pharyngitis (for the prevention of recurrent attacks of rheumatic fever).⁴

Erythromycin is contraindicated in patients with known hypersensitivity to this antibiotic.

Erythromycin is contraindicated in patients taking terfenadine, astemizole, pimozide, or cisapride. (See PRECAUTIONS - Drug Interactions . )

Do not use erythromycin concomitantly with HMG CoA reductase inhibitors (statins) that are extensively metabolized by CYP 3A4 (lovastatin or simvastatin), due to the increased risk of myopathy, including rhabdomyolysis.

Hepatotoxicity:

There have been reports of hepatic dysfunction, including increased liver enzymes, and hepatocellular and/or cholestatic hepatitis, with or without jaundice, occurring in patients receiving oral erythromycin products.

QT Prolongation:

Erythromycin has been associated with prolongation of the QT interval and infrequent cases of arrhythmia. Cases of torsades de pointes have been spontaneously reported during post-marketing surveillance in patients receiving erythromycin. Fatalities have been reported. Erythromycin should be avoided in patients with known prolongation of the QT interval, patients with ongoing proarrhythmic conditions such as uncorrected hypokalemia or hypomagnesemia, clinically significant bradycardia, and in patients receiving Class IA (quinidine, procainamide) or Class III (dofetilide, amiodarone, sotalol) antiarrhythmic agents. Elderly patients may be more susceptible to drug-associated effects on the QT interval.

Syphilis in Pregnancy:

There have been reports suggesting that erythromycin does not reach the fetus in adequate concentration to prevent congenital syphilis. Infants born to women treated during pregnancy with oral erythromycin for early syphilis should be treated with an appropriate penicillin regimen.

Clostridium difficile Associated Diarrhea:

Clostridium difficile associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including erythromycin ethylsuccinate, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile.

C. difficile produces toxins A and B which contribute to the development of CDAD. Hypertoxin producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibiotic use. Careful medical history is necessary since CDAD has been reported to occur over two months after the administration of antibacterial agents.

If CDAD is suspected or confirmed, ongoing antibiotic use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibiotic treatment of C. difficile, and surgical evaluation should be instituted as clinically indicated.

Drug Interactions

Serious adverse reactions have been reported in patients taking erythromycin concomitantly with CYP3A4 substrates. These include colchicine toxicity with colchicine; rhabdomyolysis with simvastatin, lovastatin, and atorvastatin; and hypotension with calcium channel blockers metabolized by CYP3A4 (e.g., verapamil, amlodipine, diltiazem) (see PRECAUTIONS – Drug Interactions).

There have been post-marketing reports of colchicine toxicity with concomitant use of erythromycin and colchicine. This interaction is potentially life-threatening, and may occur while using both drugs at their recommended doses (see PRECAUTIONS – Drug Interactions).

Rhabdomyolysis with or without renal impairment has been reported in seriously ill patients receiving erythromycin concomitantly with lovastatin. Therefore, patients receiving concomitant lovastatin and erythromycin should be carefully monitored for creatine kinase (CK) and serum transaminase levels. (See package insert for lovastatin.)

The most frequent side effects of oral erythromycin preparations are gastrointestinal and are dose-related. They include nausea, vomiting, abdominal pain, diarrhea and anorexia. Symptoms of hepatitis, hepatic dysfunction and/or abnormal liver function test results may occur (see WARNINGS section).

Onset of pseudomembranous colitis symptoms may occur during or after antibacterial treatment (see WARNINGS).

Erythromycin has been associated with QT prolongation and ventricular arrhythmias, including ventricular tachycardia and torsades de pointes (see WARNINGS).

Allergic reactions ranging from urticaria to anaphylaxis have occurred. Skin reactions ranging from mild eruptions to erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis have been reported rarely.

There have been reports of interstitial nephritis coincident with erythromycin use.

There have been rare reports of pancreatitis and convulsions.

There have been isolated reports of reversible hearing loss occurring chiefly in patients with renal insufficiency and in patients receiving high doses of erythromycin.

To report SUSPECTED ADVERSE REACTIONS, contact Amneal Pharmaceuticals at 1-877-835-5472 or FDA at 1‑800-FDA-1088 or www.fda.gov/medwatch.

In case of overdosage, erythromycin should be discontinued. Overdosage should be handled with the prompt elimination of unabsorbed drug and all other appropriate measures should be instituted.

Erythromycin is not removed by peritoneal dialysis or hemodialysis.

Erythromycin ethylsuccinate for oral suspension may be administered without regard to meals.           

Children:

Age, weight, and severity of the infection are important factors in determining the proper dosage. In mild to moderate infections, the usual dosage of erythromycin ethylsuccinate for children is 30 mg/kg/day to 50 mg/kg/day in equally divided doses every 6 hours. For more severe infections this dosage may be doubled. If twice-a-day dosage is desired, one-half of the total daily dose may be given every 12 hours. Doses may also be given three times daily by administering one-third of the total daily dose every 8 hours.

The following dosage schedule is suggested for mild to moderate infections:

Adults:

400 mg erythromycin ethylsuccinate every 6 hours is the usual dose. Dosage may be increased up to 4 g per day according to the severity of the infection. If twice-a-day dosage is desired, one-half of the total daily dose may be given every 12 hours. Doses may also be given three times daily by administering one-third of the total daily dose every 8 hours.

For adult dosage calculation, use a ratio of 400 mg of erythromycin activity as the ethylsuccinate to 250 mg of erythromycin activity as the stearate, base or estolate.

In the treatment of streptococcal infections, a therapeutic dosage of erythromycin ethylsuccinate should be administered for at least 10 days. In continuous prophylaxis against recurrences of streptococcal infections in persons with a history of rheumatic heart disease, the usual dosage is 400 mg twice a day.

For treatment of urethritis due to C. trachomatis or U. urealyticum: 800 mg three times a day for 7 days.

For treatment of primary syphilis: Adults: 48 g to 64 g given in divided doses over a period of 10 days to 15 days.

For intestinal amebiasis: Adults: 400 mg four times daily for 10 days to 14 days. Children: 30 mg/kg/day to  50 mg/kg/day in divided doses for 10 days to 14 days.        

For use in pertussis: Although optimal dosage and duration have not been established, doses of erythromycin utilized in reported clinical studies were 40 mg/kg/day to 50 mg/kg/day, given in divided doses for 5 days to 14 days.           

For treatment of Legionnaires' Disease: Although optimal doses have not been established, doses utilized in reported clinical data were 1.6 g to 4 g daily in divided doses.

Erythromycin ethylsuccinate for oral suspension, USP, 200 mg/5 mL, dry powder is supplied as white to off-white granules. Reconstituted suspension is off-white to light pink colored suspension.

It is available as follows:

100 mL Bottles (when mixed):                      NDC 69238-1503-1

Erythromycin ethylsuccinate for oral suspension, USP, 400 mg/5 mL, dry powder is supplied as white to off-white granules. Reconstituted suspension is off-white to light pink colored suspension.

It is available as follows:

100 mL Bottles:                      NDC 69238-1504-2

Recommended Storage:

Store erythromycin ethylsuccinate for oral suspension, USP, 200 mg/5 mL and 400 mg/5 mL, prior to mixing, below 86°F (30°C). After reconstitution, erythromycin ethylsuccinate for oral suspension, USP, 200 mg/5 mL and 400 mg/5 mL must be stored at 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature] and used within 35 days; refrigeration is not required.

1. Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease of the Council on Cardiovascular Disease in the Young, the American Heart Association: Prevention of Rheumatic Fever. Circulation. 78(4):1082-1086, October 1988.
2. Honein, M.A., et. al.: Infantile hypertrophic pyloric stenosis after pertussis prophylaxis with erythromycin: a case review and cohort study. The Lancet 1999;354 (9196): 2101-5

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Amneal Pharmaceuticals LLC
Bridgewater, NJ 08807

Rev. 04-2018-00