Erythromycin is produced by a strain of 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, and are suitable for oral administration.
ERYTHROCIN STEARATE Filmtab tablets (erythromycin stearate tablets, USP) contain the stearate salt of the antibiotic in a unique film coating.
Inactive Ingredients: 250 mg tablet: Cellulosic polymers, corn starch, D&C Red No. 7, polacrilin potassium, polyethylene glycol, povidone, propylene glycol, sodium carboxymethylcellulose, sodium citrate, sorbic acid, sorbitan monooleate and titanium dioxide.
500 mg tablet: Cellulosic polymers, corn starch, FD&C Red No. 3, magnesium hydroxide, polacrilin potassium, povidone, propylene glycol, sorbitan monooleate, titanium dioxide and vanillin.
Microbiology
Biochemical tests demonstrate that erythromycin inhibits protein synthesis of the pathogen without directly affecting nucleic acid synthesis. Antagonism has been demonstrated between clindamycin and erythromycin.
NOTE: Many strains of Hemophilus influenzae are resistant to erythromycin alone, but are susceptible to erythromycin and sulfonamides together. Staphylococci resistant to erythromycin may emerge during a course of erythromycin therapy. Culture and susceptibility testing should be performed.
Disc Susceptibility Tests:
Quantitative methods that require measurement of zone diameters give the most precise estimates of antibiotic susceptibility. One recommended procedure (21 CFR section 460.1) uses erythromycin class discs for testing susceptibility; interpretations correlate zone diameters of this disc test with MIC values for erythromycin. With this procedure, a report from the laboratory of "susceptible" indicates that the infecting organism is likely to respond to therapy. A report of "resistant" indicates that the infective organism is not likely to respond to therapy. A report of "intermediate susceptibility" suggests that the organism would be susceptible if higher doses were used.
Erythromycin binds to the 50 S ribosomal subunits of susceptible bacteria and suppresses protein synthesis.
Orally administered ERYTHROCIN STEARATE tablets are readily and reliably absorbed. Optimal serum levels of erythromycin are reached when the drug is taken in the fasting state or immediately before meals.
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 and is excreted in breast milk.
Streptococcus pyogenes (Group A beta hemolytic streptococcus): Upper and lower respiratory tract, skin, and soft tissue infections of mild to moderate severity.
Injectable benzathine penicillin G is considered by the American Heart Association to be the drug of choice in the treatment and prevention of streptococcal pharyngitis and in long-term prophylaxis of rheumatic fever.
When oral medication is preferred for treatment of the above conditions, penicillin G, V, or erythromycin are alternate drugs of choice.
When oral medication is given, the importance of strict adherence by the patient to the prescribed dosage regimen must be stressed. A therapeutic dose should be administered for at least 10 days.
Alpha-hemolytic streptococci (viridans group):
Although no controlled clinical efficacy trials have been conducted, oral erythromycin has been suggested by the American Heart Association and American Dental Association for use in a regimen for prophylaxis against bacterial endocarditis in patients hypersensitive to penicillin who have congenital heart disease, or rheumatic or other acquired valvular heart disease when they undergo dental procedures and surgical procedures of the upper respiratory tract. 1 Erythromycin is not suitable prior to genitourinary or gastrointestinal tract surgery. NOTE: When selecting antibiotics for the prevention of bacterial endocarditis the physician or dentist should read the full joint statement of the American Heart Association and the American Dental Association. 1
Staphylococcus aureus: Acute infections of skin and soft tissue of mild to moderate severity. Resistant organisms may emerge during treatment.
Streptococcus pneumoniae (Diplococcus pneumoniae): Upper respiratory tract infections (e.g., otitis media, pharyngitis) and lower respiratory tract infections (e.g., pneumonia) of mild to moderate degree.
Mycoplasma pneumoniae (Eaton agent, PPLO): For respiratory infections due to this organism.
Hemophilus influenzae: For upper respiratory tract infections of mild to moderate severity when used concomitantly with adequate doses of sulfonamides. (See sulfonamide labeling for appropriate prescribing information.) The concomitant use of the sulfonamides is necessary since not all strains of Hemophilus influenzae are susceptible to erythromycin at the concentrations of the antibiotic achieved with usual therapeutic doses.
Chlamydia trachomatis: Erythromycin is indicated for 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. 2
Treponema pallidum: Erythromycin is an alternate choice of treatment for primary syphilis in patients allergic to the penicillins. In treatment of primary syphilis, spinal fluid examinations should be done before treatment and as part of follow-up after therapy.
Corynebacterium diphtheriae: As an adjunct to antitoxin, to prevent establishment of carriers, and to eradicate the organism in carriers.
Corynebacterium minutissimum: For the treatment of erythrasma.
Entamoeba histolytica: In the treatment of intestinal amebiasis only. Extra-enteric amebiasis requires treatment with other agents.
Listeria monocytogenes: Infections due to this organism.
Neisseria gonorrhoeae: Erythrocin Lactobionate-I.V. (erythromycin lactobionate for injection) in conjunction with erythromycin stearate orally, 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. Before treatment of gonorrhea, patients who are suspected of also having syphilis should have a microscopic examination for T. pallidum (by immunofluorescence or darkfield) before receiving erythromycin, and monthly serologic tests for a minimum of 4 months.
Bordetella pertussis: Erythromycin is effective in eliminating the organism from the nasopharynx of infected individuals, rendering them non-infectious. Some clinical studies suggest that erythromycin may be helpful in the prophylaxis of pertussis in exposed susceptible individuals.
Legionnaires' Disease: 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.
Erythromycin is contraindicated in patients with known hypersensitivity to this antibiotic.
There have been reports of hepatic dysfunction with or without jaundice, occurring in patients receiving oral erythromycin products.
General: Erythromycin is principally excreted by the liver. Caution should be exercised when erythromycin is administered to patients with impaired hepatic function. (See " " and " " sections.)
Prolonged or repeated use of erythromycin may result in an overgrowth of nonsusceptible bacteria or fungi. If superinfection occurs, erythromycin should be discontinued and appropriate therapy instituted.
When indicated, incision and drainage or other surgical procedures should be performed in conjunction with antibiotic therapy.
Laboratory Tests: Erythromycin interferes with the fluorometric determination of urinary catecholamines.
Drug Interactions: Erythromycin use in patients who are receiving high doses of theophylline may be associated with an increase in serum theophylline levels and potential theophylline toxicity. In case of theophylline toxicity and/or elevated serum theophylline levels, the dose of theophylline should be reduced while the patient is receiving concomitant erythromycin therapy.
Concomitant administration of erythromycin and digoxin has been reported to result in elevated digoxin serum levels.
There have been reports of increased anticoagulant effects when erythromycin and oral anticoagulants were used concomitantly.
Concurrent use of erythromycin and ergotamine or dihydroergotamine has been associated in some patients with acute ergot toxicity characterized by severe peripheral vasospasm and dysesthesia.
Erythromycin has been reported to decrease the clearance of triazolam and thus may increase the pharmacologic effect of triazolam.
The use of erythromycin in patients concurrently taking drugs metabolized by the cytochrome P450 system may be associated with elevations in serum erythromycin with carbamazepine, cyclosporine, hexobarbital and phenytoin. Serum concentrations of drugs metabolized by the cytochrome P450 system should be monitored closely in patients concurrently receiving erythromycin.
Troleandomycin significantly alters the metabolism of terfenadine when taken concomitantly; therefore, observe caution when erythromycin and terfenadine are used concurrently.
Patients receiving concomitant lovastatin and erythromycin should be carefully monitored; cases of rhabdomyolysis have been reported in seriously ill patients.
Carcinogenesis, Mutagenesis, Impairment of Fertility: Long-term (2-year) oral studies conducted in rats with erythromycin base did not provide evidence of tumorigenicity. Mutagenicity studies have not been conducted. There was no apparent effect on male or female fertility in rats fed erythromycin (base) at levels up to 0.25 percent of diet.
Pregnancy: Pregnancy Category B: There is no evidence of teratogenicity or any other adverse effect on reproduction in female rats fed erythromycin base (up to 0.25 percent of diet) prior to and during mating, during gestation, and through weaning of two successive litters. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed. Erythromycin has been reported to cross the placental barrier in humans, but fetal plasma levels are generally low.
Labor and Delivery: The effect of erythromycin on labor and delivery is unknown.
Nursing Mothers: Erythromycin is excreted in breast milk, therefore, caution should be exercised when erythromycin is administered to a nursing woman.
Pediatric Use: See " and Usage" and " Dosage and Administration " sections.
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 hepatic dysfunction and/or abnormal liver function test results may occur (see " " section). Pseudomembranous colitis has been rarely reported in association with erythromycin therapy.
There have been isolated reports of transient central nervous system side effects including confusion, hallucinations, seizures, and vertigo; however, a cause and effect relationship has not been established.
Occasional case reports of cardiac arrhythmias such as ventricular tachycardia have been documented in patients receiving erythromycin therapy. There have been isolated reports of other cardiovascular symptoms such as chest pain, dizziness, and palpitations; however, a cause and effect relationship has not been established.
Allergic reactions ranging from urticaria and mild skin eruptions to anaphylaxis have occurred.
There have been isolated reports of reversible hearing loss occurring chiefly in patients with renal insufficiency and in patients receiving high doses of erythromycin.
In case of overdosage, erythromycin should be discontinued. Overdosage should be handled with the prompt elimination of unabsorbed drug and all other appropriate measures.
Erythromycin is not removed by peritoneal dialysis or hemodialysis.
Optimal serum levels of erythromycin are reached when ERYTHROCIN STEARATE (erythromycin stearate) is taken in the fasting state or immediately before meals.
Adults: The usual dosage is 250 mg every 6 hours; or 500 mg every 12 hours, taken in the fasting state or immediately before meals. Up to 4 g per day may be administered, depending upon the severity of the infection.
Children: Age, weight, and severity of the infection are important factors in determining the proper dosage. For the treatment of mild to moderate infections, the usual dosage is 30 to 50 mg/kg/day in 3 or 4 divided doses. When dosage is desired on a twice-a-day schedule, one-half of the total daily dose may be taken every 12 hours in the fasting state or immediately before meals. For the treatment of more severe infections the total daily dose may be doubled.
In the treatment of streptococcal infections, a therapeutic dosage of erythromycin should be administered for at least 10 days. In continuous prophylaxis of streptococcal infections in persons with a history of rheumatic heart disease, the dose is 250 mg twice a day.
For prophylaxis against bacterial endocarditis 1 in patients with congenital heart disease, or rheumatic or other acquired valvular heart disease when undergoing dental procedures or surgical procedures of the upper respiratory tract, give 1 g (20 mg/kg for children) orally 1 ½ to 2 hours before the procedure, and then, 500 mg (10 mg/kg for children) orally every 6 hours for 8 doses.
For conjunctivitis of the newborn caused by Chlamydia trachomatis: Oral erythromycin suspension 50 mg/kg/day in 4 divided doses for at least 2 weeks. 2
For pneumonia of infancy caused by Chlamydia trachomatis. Although the optimal duration of therapy has not been established, the recommended therapy is oral erythromycin suspension 50 mg/kg/day in 4 divided doses for at least 3 weeks. 2
For urogenital infections during pregnancy due to Chlamydia trachomatis: Although the optimal dose and duration of therapy have not been established, the suggested treatment is erythromycin 500 mg, by mouth, 4 times a day on an empty stomach for at least 7 days. For women who cannot tolerate this regimen, a decreased dose of 250 mg, by mouth, 4 times a day should be used for at least 14 days. 2
For adults with uncomplicated urethral, endocervical, or rectal infections caused by Chlamydia trachomatis in whom tetracyclines are contraindicated or not tolerated: 500 mg, by mouth, 4 times a day for at least 7 days. 2
For treatment of primary syphilis: 30 to 40 g given in divided doses over a period of 10 to 15 days.
For treatment of acute pelvic inflammatory disease caused by N. gonorrhoeae: 500 mg Erythrocin Lactobionate-I.V. (erythromycin lactobionate for injection) every 6 hours for 3 days, followed by 250 mg ERYTHROCIN STEARATE every 6 hours for 7 days.
For intestinal amebiasis: Adults: 250 mg four times daily for 10 to 14 days. Children: 30 to 50 mg/kg/day in divided doses for 10 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 to 50 mg/kg/day, given in divided doses for 5 to 14 days.
For treatment of Legionnaires' Disease: Although optimal doses have not been established, doses utilized in reported clinical data were 1 to 4 g daily in divided doses.
ERYTHROCIN STEARATE Filmtab Tablets (erythromycin stearate tablets, USP) are supplied as:
ERYTHROCIN STEARATE Filmtab, 250 mg
Bottles of 100 ............................. ( NDC 0074-6346-20)
Bottles of 500 ............................. ( NDC 0074-6346-53)
Bottles of 1000 ........................... ( NDC 0074-6346-19)
ABBO-PAC® unit dose strip packages of
100 tablets .................................. ( NDC 0074-6346-38)
ERYTHROCIN STEARATE Filmtab, 500 mg
Bottles of 100 ............................. ( NDC 0074-6316-13)
Recommended storage: below 86°F (30°C).
FILMTAB--Film-sealed tablets, Abbott
Ref. 01-2538-R13
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