November 2009

 

OPHTHALMOLOGY NEWS

 

Erythromycin shortage to last through December


by Michelle Dalton EyeWorld Contributing Editor

   

With production of erythromycin potentially slowed until 2010, other antibacterials are “acceptable options,” according to CDC

In mid-September, the U.S. Food and Drug Administration (FDA) was made aware of a shortage of erythromycin ophthalmic ointment 0.5% as a result of a manufacturer change. Fera Pharmaceuticals (New York) acquired all rights to erythromycin (and six other prescription anti-infective topical ophthalmic drugs) from Fougera (Melville, N.Y.) in July. According to the Fera Web site, the company plans to begin shipping product as soon as the technical transfers are completed (some time in early 2010). “Bausch & Lomb (Rochester, N.Y.) also manufactures erythromycin ophthalmic ointment and they are working to increase production during this period of drug shortage,” the FDA said. “We anticipate shortage of both the 1 gram and 3.5 gram tubes.”

In the U.S., erythromycin ophthalmic ointment is approved for the prophylaxis of ophthalmia neonatorum due to Neisseria gonorrhoeae or Chlamydia trachomatis. The disease is a form of bacterial conjunctivitis that may be contracted by newborns during delivery. Erythromycin is the only drug currently approved for this use, the FDA noted. The macrolide antibiotic “is also approved for the treatment of superficial ocular infections involving the conjunctiva and/or cornea caused by organisms susceptible to erythromycin,” the FDA said.

As a result of the shortage, the FDA is asking healthcare providers to consider alternative drugs to treat ocular infections and reserve erythromycin for the neonatal purposes. The Centers for Disease Control and Prevention (CDC) has provided guidance, saying “our experts indicate that AzaSite (azithromycin ophthalmic solution 1%, Inspire Pharmaceuticals, Durham, N.C.) is an acceptable alternative,” if erythromycin is not available. Should AzaSite also be unavailable, the CDC recommended using gentamicin ophthalmic ointment 0.3%, tobramycin ophthalmic ointment 0.3%, or a fluoroquinolone such as ciprofloxacin 0.3%, although the CDC noted efficacy data is not available for any of the suggested alternate regimens for the neonatal indication.

In response to the shortage, Inspire has said it will ramp up its production of AzaSite. “The CDC recommended AzaSite as an acceptable substitute for neonatal prophylaxis use where erythromycin ophthalmic ointment is not available,” the company said. Although the drug is formulated for topical ophthalmic use, AzaSite “has not been approved by the FDA for the treatment of prophylaxis of ophthalmia neonatorum and no clinical trials have been conducted using AzaSite in this population,” Inspire said.

According to the IMS National Disease and Therapeutic Index, August 2009, AzaSite is already prescribed more often for several ophthalmic indications than erythromycin: 17.6% of the prescriptions for the treatment of blepharitis are for AzaSite, compared with 4.45% for erythromycin and 5.35% for bacitracin. However, both AzaSite and erythromycin are prescribed about evenly for conjunctivitis and keratitis. Erythromycin is prescribed significantly more often than AzaSite for endophthalmitis (13.1% vs. 5.6%, respectively), corneal ulcer (1.8% vs. 0.9%, respectively), and surgical prophylaxis (2.3% vs. 1.9%, respectively).

“For surgeons who have been using erythromycin for surgical prophylaxis, AzaSite is a much more effective agent at eliminating bacteria,” said William B. Trattler, M.D., director, Cornea, Center for Excellence in Eye Care, Miami. While both of these drugs belong to the macrolide class of antibiotics, Azasite is more potent, has a much broader spectrum of action, longer duration of action, and greater tissue penetration when compared to erythromycin, he added.

Dr. Trattler said Azasite reaches “very high levels” in the cornea, conjunctiva, and eyelid, with much better MICs than erythromycin. The higher levels are useful for infection prevention after various ocular and lid surgeries. Once these high levels of drug are achieved, they remain elevated well above the MICs for most common organisms that cause ocular infections for several days, Dr. Trattler said. “I think [azithromycin] is a great alternative to erythromycin, and the CDC/FDA seem to agree,” he said. In fact, due to the current shortage in the supply of erythromycin ophthalmic ointment, the CDC has recommended AzaSite as an acceptable substitute for neonatal prophylaxis use where erythromycin ophthalmic ointment is not available.

Regarding surgery, Dr. Trattler said, “I certainly don’t use AzaSite in place of a fluoroquinolone, but I do use it in conjunction with a fluoroquinolone in a portion of my patients undergoing cataract surgery.”

The seven drugs Fera bought from Fougera—bacitracin; bacitracin zinc and polymyxin B sulfate; gentamicin sulfate, neomycin and polymyxin B sulfates and bacitracin zinc; neomycin and polymyxin B sulfates and dexamethasone; neomycin and polymyxin B sulfates, bacitracin zinc and hydrocortsone acetate; and erythromycin—represent about 80% of the ophthalmic ointment market volume, according to IMS Health.

Editors’ note: Dr. Trattler has financial interests with Inspire Pharmaceuticals (Durham, N.C.).

Contact information

Trattler: 305-598-2020, wtrattler@gmail.com

Erythromycin shortage to last through December Erythromycin shortage to last through December
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