Erythromycin base
Erythromycin base (Eryc)
Erythromycin
(eh- rih-throw- MY-sin)
Pregnancy Category: B (A/T/S, Erymax, Staticin, and T-Stat are C) Capsules/Tablets: Alti-Erythromycin Apo-Erythro Base Apo-Erythro-EC Diomycin E-Base E-Mycin Erybid Eryc Ery-Tab Erythro-Base Erythromid Erythromycin Base Film-Tabs Novo-Rythro EnCap PCE Dispertab PMS-Erythromycin Gel topical:A/T/S Erygel. Ointment topical: Akne-mycin. Ointment ophthalmic: Ilotycin Ophthalmic Pledgets: Erycette T-Stat. Solution: Del-Mycin Eryderm 2% Erymax Erythra-Derm Staticin Theramycin Z T-Stat (Rx)

Classification: Antibiotic, erythromycin

See Also: See also Anti-Infective Agents .

Action/Kinetics: Erythromycins are macrolide antibiotics. They inhibit protein synthesis of microorganisms by binding reversibly to a ribosomal subunit (50S), thus interfering with the transmission of genetic information and inhibiting protein synthesis. The drugs are effective only against rapidly multiplying organisms. Absorbed from the upper part of the small intestine. Those for PO use are manufactured in enteric-coated or film-coated forms to prevent destruction by gastric acid. Erythromycin is approximately 70% bound to plasma proteins and achieves concentrations in body tissues about 40% of those in the plasma. Diffuses into body tissues; peritoneal, pleural, ascitic, and amniotic fluids; saliva; through the placental circulation; and across the mucous membrane of the tracheobronchial tree. Diffuses poorly into spinal fluid, although penetration is increased in meningitis. Alkalinization of the urine (to pH 8.5) increases the gram-negative antibacterial action. Peak serum levels: PO 1-4 hr. t 1/2: 1.5-2 hr, but prolonged in clients with renal impairment. Partially metabolized by the liver and primarily excreted in bile. Also excreted in breast milk.

Uses:

1. Mild to moderate upper respiratory tract infections due to Streptococcus pyogenes (group a beta-hemolytic streptococci), Streptococcus pneumoniae and Haemophilus influenzae (combined with sulfonamides).

2. Mild to moderate lower respiratory tract infections due to S. pyogenes (group a beta-hemolytic streptococci) and S. pneumoniae. Respiratory tract infections due to Mycoplasma pneumoniae.

3. Pertussis (whooping cough) caused by Bordetella pertussis; may also be used as prophylaxis of pertussis in exposed individuals.

4. Mild to moderate skin and skin structure infections due to S. pyogenes and Staphylococcus aureus. Topically for acne vulgaris.

5. As an adjunct to antitoxin in diphtheria (caused by Corynebacterium diphtheriae), to prevent carriers, and to eradicate the organism in carriers.

6. Intestinal amebiasis due to Entamoeba histolytica (PO erythromycin only).

7. Acute pelvic inflammatory disease due to Neisseria gonorrhoeae.

8. Erythrasma due to Corynebacterium minutissimum.

9. Chlamydia trachomatis infections causing urogenital infections during pregnancy, conjunctivitis in the newborn, or pneumonia during infancy. Also, uncomplicated chlamydial infections of the urethra, endocervix, or rectum in adults (when tetracyclines are contraindicated or not tolerated).

10. Nongonococcal urethritis caused by Ureaplasma urealyticum when tetracyclines are contraindicated or not tolerated.

11. Legionnaires' disease due to Legionella pneumophilia.

12. PO as an alternative to penicillin (in penicillin-sensitive clients) to treat primary syphilis caused by Treponema pallidum.

13. Prophylaxis of initial or recurrent attacks of rheumatic fever in clients allergic to penicillin or sulfonamides.

14. Infections due to Listeria monocytogenes.

15. Bacterial endocarditis due to alpha-hemolytic streptococci, Viridans group, in clients allergic to penicillins.

Contraindications: Hypersensitivity to erythromycin; in utero syphilis. Use of topical preparations in the eye or near the nose, mouth, or any mucous membrane. Ophthalmic use in dendritic keratitis, vaccinia, varicella, myobacterial infections of the eye, fungal diseases of the eye. Use with steroid combinations following uncomplicated removal of a corneal foreign body.

Special Concerns: Use with caution in liver disease and during lactation. Use may result in bacterial and fungal overgrowth (i.e., superinfection). Use of other drugs for acne may result in a cumulative irritant effect. Although still recommended, use to treat whooping cough in newborns may cause pyloric stenosis.

Side Effects: GI: Abdominal discomort or pain, anorexia, diarrhea or loose stools, dyspepsia, flatulence, GI disorder, N&V;, pseudomembranous colitis, hepatotoxicity. CV: Ventricular arrhythmias, including ventricular tachycardia and torsades de pointes in clients with prolonged QT intervals. After IV, increase in heart rate and prolongation of QT interval. Dermatologic: Pruritus, rash, urticaria, bullous eruptions, eczema, erythema multiforme, Stevens-Johnson syndrome, toxic epidermal necrolysis. CNS: Dizziness, headache, insomnia. Miscellaneous: Asthenia, dyspnea, increased cough, non-specific pain, vaginitis, allergic reaction, anaphylaxis. Reversible hearing loss in those with renal or hepatic insufficiency, in the elderly, and after doses greater than 4 g/day.
Following IV use: Venous irritation, thrombophlebitis. Following IM use: Pain at the injection site, with development of necrosis or sterile abscesses. Following topical use: Itching, burning, irritation, stinging of skin; dry, scaly skin. When used topically: Erythema, desquamation, burning sensation, eye irritation, tenderness, dryness, pruritus, oily skin, generalized urticaria.

Laboratory Test Alterations: Interference with fluorometric assay for urinary catecholamines. Bicarbonate, eosinophils, platelet count, segmented neutrophils, serum CPK.

Overdose Management: Symptoms: N&V;, diarrhea, epigastric distress, acute pancreatitis (mild), hearing loss (with or without tinnitus and vertigo). Treatment: Induce vomiting. General supportive measures. Allergic reactions should be controlled with conventional therapy.

Drug Interactions: Alfentanil / Alfentanil excretion effect Anticoagulants / Anticoagulant effects possible hemorrhage Antacids / Slight in elimination rate of erythromycin Benzodiazepines (Alprazolam, Diazepam, Midazolam, Triazolam) / Plasma benzodiazepine levels CNS depressant effects Bromocriptine / Serum bromocriptine levels pharmacologic and toxic effects Buspirone / Plasma buspirone levels pharmacologic and toxic effects Carbamazepine / Carbamazepine effect (and toxicity requiring hospitalization and resuscitation) R/T liver breakdown Cisapride / Possible serious cardiac arrhythmias, including VT, VF, torsades de pointes, and prolonged QT interval Clindamycin / Antagonism of effect if used together topically Cyclosporine / Cyclosporine effect R/T excretion (possibly with renal toxicity) Digoxin / Serum digoxin levels R/T effect on gut flora Disopyramide / Plasma disopyramide levels arrhythmias and QTc intervals Ergot alkaloids / Acute ergotism manifested by peripheral ischemia and dysesthesia Felodipine / Felodipine drug levels pharmacologic and toxic effects Grepafloxacin / Risk of life-threatening cardiac arrhythmias, including torsades de pointes HMG-CoA Reductase inhibitors / Risk of myopathy or rhabdomyolysis; also plasma levels of atorvastatin, cerivastatin, lovastatin, or simvastatin R/T liver breakdown Methylprednisolone / Methylprednisolone effect R/T liver breakdown Penicillin / Either or effect of penicillins Pimozide / Possibility of sudden death; do not use together Rifabutin, Rifambpin / Effect of erythromycin; risk of GI side effects Sodium bicarbonate / Effect of erythromycin in urine due to alkalinization Sparfloxacin / Risk of life-threatening cardiac arrhythmias, including torsades de pointes Tacrolimus / Serum tacrolimus levels risk of nephrotoxicity Terfenadine / Serious CV side effects, including torsades de pointes and other ventricular arrhythmias (including QT interval prolongation), cardiac arrest, and death Theophyllines / Theophylline effects R/T liver breakdown; erythromycin levels may also occur Vinblastine / Risk of vinblastine toxicity (constipation, myalgia, neutropenia)

How Supplied: Enteric Coated Capsule: 250 mg; Enteric Coated Tablet: 250 mg, 333 mg, 500 mg; Gel/Jelly: 2%; Ointment: 2%; Ophthalmic ointment: 5 mg/g; Pad: 2%; Solution: 1.5%, 2%; Swab: 2%; Tablet: 250 mg, 500 mg; Tablet, Coated Particles: 333 mg, 500 mg

Dosage
Note: Doses are listed as erythromycin base. ?Delayed-Release Capsules, Enteric-Coated Tablets, Delayed-Release Tablets, Film-Coated Tablets, Suspension Respiratory tract infections due to Mycoplasma pneumoniae.
500 mg q 6 hr for 5-10 days (up to 3 weeks for severe infections).
Upper respiratory tract infections (mild to moderate) due to S. pyogenes and S. pneumoniae.
Adults: 250-500 mg q.i.d. for 10 days. Children: 20-50 mg/kg/day in divided doses, not to exceed the adult dose, for 10 days.
URTIs due to H. influenzae.
Erythromycin ethylsuccinate, 50 mg/kg/day for children, plus sulfisoxazole, 150 mg/kg/day, given together for 10 days.
Lower respiratory tract infections (mild to moderate) due to S. pyogenes and S. pneumoniae.
250-500 mg q.i.d. (or 20-50 mg/kg/day in divided doses) for 10 days.
Intestinal amebiasis due to Entamoeba histolytica.
Adults: 250 mg q.i.d. for 10-14 days; pediatric: 30-50 mg/kg/day in divided doses for 10 days.
Legionnaire's disease.
1-4 g/day in divided doses for 10-14 days.
Bordetella pertussis.
500 mg q.i.d. for 10 days (or for children, 40-50 mg/kg/day in divided doses for 5-14 days).
Infections due to Corynebacterium diphtheriae.
500 mg q 6 hr for 10 days.
Primary syphilis.
20-40 g in divided doses over 10 days.
Conjunctivitis of the newborn, pneumonia of infancy, urogenital infections during pregnancy due to Chlamydia trachomatis.
Infants: 50 mg/kg/day in four divided doses for 14 (conjunctivitis) to 21 (pneumonia) days; adults: 500 mg q.i.d. for 7 days or 250 mg q.i.d. for 14 days for urogenital infections.
Mild to moderate skin and skin structure infections due to S. pyogenes and S. aureus.
250-500 mg q 6 hr (or 20-50 mg/kg/day for children, in divided doses--to a maximum of 4 g/day) for 10 days.
Listeria monocytogenes infections.
Adults: 500 mg q 12 hr (or 250 mg q 6 hr), up to maximum of 4 g/day.
Pelvic inflammatory disease, acute N. gonorrhoeae.
Erythromycin lactobionate, 500 mg IV q 6 hr for 3 days; then, 250 mg erythromycin base 250 mg PO q 6 hr for 7 days. Alternatively for pelvic inflammatory disease, 500 mg PO q.i.d. for 10-14 days.
Prophylaxis of initial or recurrent rheumatic fever.
250 mg b.i.d.
Bacterial endocarditis due to alpha-hemolytic streptococcus.
Adults: 1 g 1-2 hr prior to the procedure; then, 500 mg 6 hr after the initial dose. Pediatric, 20 mg/kg 2 hr prior to the procedure; then, 10 mg/kg 6 hr after the initial dose.
Uncomplicated urethral, endocervicial, or rectal infections due to C. trachomatis.
500 mg q.i.d. for 7 days (or 250 mg q.i.d. for 14 days).
Nongonococcal urethritis due to Ureaplasma urealyticum.
500 mg q.i.d. for at least 7 days or 250 mg q.i.d. for 14 days if client can not tolerate high doses of erythromycin.
Erythrasma due to Corynebacterium minutissimum.
250 mg t.i.d. for 21 days.
?Ophthalmic Ointment Mild to moderate infections.
0.5-in. ribbon b.i.d.-t.i.d.
Acute infections.
0.5 in. q 3-4 hr until improvement is noted.
Prophylaxis of neonatal gonococcal or chlamydial conjunctivitis.
0.2-0.4 in. into each conjunctival sac.
?Topical Gel (2%), Ointment (2%), Solution (2%)
Clean the affected area and apply, using fingertips or applicator, morning and evening, to affected areas. If no improvement is seen after 6 to 8 weeks, discontinue therapy.
?Investigational Uses. Diarrhea due to Campylobacter enteritis or enterocolitis. Chancroid due to Haemophilus ducreyi.
500 mg q.i.d. for 7 days.
Genital, inguinal, or anorectal Lymphogranuloma venereum. Early syphilis due to Treponema palliduim.
500 mg q.i.d. for 14 days.
Tetanus due to Clostridium tetani.
500 mg q 6 hr for 10 days.
Granuloma inguinale due to Calymmatobacterium granulomatis.
500 mg PO q.i.d. for 21 or more days.