FDA Issues Caution Over Moxifloxacin Eye Injections

Last month, the FDA issued an alert about potential risks associated with the intraocular use of compounded moxifloxacin. The FDA had received reports of toxic anterior segment syndrome (TASS) following injections of compounded drugs containing bulk moxifloxacin or repackaged and diluted FDA-approved moxifloxacin medications. A search of the FDA’s Adverse Event Reporting System database identified 29 cases of TASS associated with drugs containing moxifloxacin. Among the reports, 16 involved drugs compounded with bulk moxifloxacin; 10 were associated with repackaged Moxeza, a preservative-containing form of moxifloxacin; the remaining incidents involved unspecified (repackaged and/or diluted) forms of Vigamox and Moxeza. Nineteen cases involved cataract surgery; the others did not specify the type of eye surgery in which the drugs were used.

The FDA released the alert to inform providers that it’s considering placing bulk moxifloxacin on the list of medications that should not be compounded for ophthalmic use. Many ophthalmic surgeons administer moxifloxacin during cataract surgery to reduce the risk of post-op endophthalmitis, which the FDA says is estimated to occur in .012% to 1.3% of cases.

There is no FDA-approved moxifloxacin product, but approximately half of ophthalmic surgeons administer intracameral moxifloxacin at the time of cataract surgery, according to Eric Donnenfeld, MD, a cataract specialist at Ophthalmic Consultants of Long Island in Garden City, N.Y. “Approximately four million cataract cases are performed each year, so about 2 million patients are administered intracameral moxifloxacin annually,” he says. “With that perspective, twenty-nine cases of TASS is a very low number.”

Dr. Donnenfeld emphasizes 10 of the 29 cases that the FDA cited were associated with the intracameral use of Moxeza, an FDA-approved topical drop that is not indicated for intraocular injection. Moxeza contains xanthan gum and sorbitol, among other inactive ingredients, which have been linked to TASS. The drug’s labeling notes it is for topical use only and should not be repackaged or compounded for intraocular injection.

Moxifloxacin is one of the most important medications used to prevent endophthalmitis.
— Eric Donnenfeld, MD

“One third of the TASS cases were caused by the inappropriate use of a medication that has nothing to do with bulk moxifloxacin,” says Dr. Donnenfeld.

The American Society of Cataract and Refractive Surgeons (ASCRS) and the American Academy of Ophthalmology (AAO) have written letters to the FDA to express their support for the use of bulk moxifloxacin, according to Dr. Donnenfeld. He says losing the use of bulk moxifloxacin would force surgeons to explore other more expensive alternatives, which would take a larger cut out of CMS’s cataract surgery bundle.

“Moxifloxacin is one of the most important medications used to prevent endophthalmitis,” says Dr. Donnenfeld. “There have been thousands of studies showing it reduces endophthalmitis with millions of patients having received the medication, making it one of the most studied drugs in ophthalmology.

Dr. Donnenfeld believes the risk of not using bulk moxifloxacin is greater than the risk of using compounded medications. “That has become less of a problem in recent years now that ophthalmic facilities are partnering with reputable compounding pharmacies,” he says. “Most pharmacies practice safe levels of sterility when compounding their medications. Making access to moxifloxacin more onerous for surgeons would place patients at risk. We simply want to maintain the status quo.”

All intraocular use of moxifloxacin is off label, points out Roy S. Chuck, MD, PhD, chairman of the department of ophthalmology and visual sciences at Albert Einstein College of Medicine Montefiore Medical Center in the Bronx, N.Y. However, he was surprised to learn some surgeons are using Moxeza, a drug that shouldn’t be used for intracameral injections.

Many surgeons began injecting non-preservative forms of moxifloxacin inside the eye to avoid issues of compliance with post-op antibiotic drop regimens, according to Dr. Chuck.

“There’s no proof that any antibiotic injected into the eye pre- or postoperatively prevents endophthalmitis,” says Dr. Chuck. “Trials suggest it’s effective, but it’s never been definitively proven. I’m still a believer in using intracameral antibiotics, but we need a product that’s well-regulated.”

There have been fewer TASS outbreaks in recent years. “Ophthalmic professionals have taken preventative measures to heart and are doing a good job of limiting risk factors,” says Dr. Chuck. “There are many variables that contribute to the development of TASS, but at least there are protocols to follow that effectively lower the risk.”

You should allow adequate time for the proper cleaning and sterilization of ophthalmic instrumentation, according to ASCRS’s TASS guidelines (osmag.net/8SnxWC). Transport soiled instruments to the reprocessing area in a closed container and ensure lumened instruments are thoroughly rinsed. Also be sure viscoelastic agents don’t have a chance to dry on used instruments by immediately wiping them with a damp, lint-free cloth and flushing or immersing them in sterile water at the point of use. Clean ophthalmic instruments separately from other types of instrumentation. Also use disposable cannulas and tubing whenever possible.

“Incidence remains low because facilities are following preventative protocols,” says Dr. Donnenfeld. “However, constant vigilance remains essential.” OSM