Erythromycin is a broad-spectrum, macrolide antibiotic. It has activity against many gram-positive organisms (including
Staphylococcus spp and
Streptococcus spp) and some gram-negative organisms. It is also effective for mycoplasma infections. Increased bacterial resistance to erythromycin is reported.
In the United States, erythromycin is one of the few drugs approved by the FDA for use in egg laying hens.
Drug Storage: Erythromycin should be stored in the refrigerator until right before giving it to the bird, after which it can be stored at room temperature for no more than 14 days.
Egg Withdrawal Period: In the United States, Ireland, United Kingdom, and Australia, erythromycin is approved for use in laying hens producing eggs intended for human consumption when its given in accordance with each product manufacturer's label directions; where it has a 0-day egg withdrawal period.
Caution: - Poultry with existing liver or kidney disease, electrolyte imbalances, or heart rhythm disorders have an increased risk of the associated side effects of this medication.
- Given via IM injection can cause muscle necrosis.
- Do not concurrently administer apple cider vinegar in the drinking water of chickens who are receiving this drug. The acidic environment deactivates the drug.
Storage
Oral formulations: erythromycin estolate and erythromycin ethylsuccinate (EES 200 and 400) liquid suspensions maintain their potency for 14 days at room temperature. Refrigeration maintains optimal taste. Tablets should not be crushed.
Topical: stable for 2 years when stored at room temperature. Gel and pledgets should be stored at room temperature while ointment should be stored under 27° C (81° F). An extemporaneous topical solution made from tablets with hydroalcoholic vehicle as a 2% solution was stable for 60 days at 25° C (77° F). A 2.7% preparation in E-Solve was stable for 4 months when refrigerated between 4° C and 8° C (39° F and 46° F).
Injection: stable at room temperature in dry form. Reconstituted IV solution should be used within 8 hours after preparation or within 24 hours if refrigerated. Drug stability may be maintained up to 2 weeks if refrigerated but carries significant risk of contamination. Solution may be frozen for 30 days and is stable if used within 8 hours of thawing under refrigeration conditions. Do not refreeze thawed solution.
