Eye Surgeons Need Patients' Complete Drug Profiles

BETHESDA, MD, 23 August 2006 — Even an alpha-1-receptor blocker taken most recently as five years ago can cause complications during cataract surgery, according to one of the ophthalmologists researching the apparent relationship.

"There seems to be some semipermanent effect of the alpha-blockers, such as Flomax or tamsulosin, on the iris muscles, said David F. Chang, speaking on behalf of the American Academy of Ophthalmology during a conference call yesterday with reporters.

The academy, along with the American Society of Cataract and Refractive Surgery and the American Urological Association, issued an advisory (PDF) to patients taking "prostate drugs" and awaiting cataract surgery.

Patients taking tamsulosin, terazosin, doxazosin, or alfuzosin, the advisory states, must inform their eye surgeon about that medication before undergoing ophthalmologic surgery.

All four of those alpha-blockers treat benign prostatic hypertrophy. The FDA-approved labeling for terazosin and doxazosin also describe the drugs' efficacy in the treatment of hypertension.

Chang and fellow ophthalmologist John R. Campbell reported in 2005 that Flomax, the tamsulosin product marketed by Boehringer Ingelheim Pharmaceuticals Inc., appears to block the iris dilator muscle. The result is an iris that tends to be floppy and a pupil that may unexpectedly constrict during the middle of cataract surgery rather than stay dilated. If not anticipated by the surgeon, a floppy iris can lead to complications.

Boehringer Inhelheim issued a "Dear Doctor" letter in November 2005 and revised the FDA-approved labeling for Flomax. The other makers of alpha-blockers revised their products' labeling as well.

Subsequent research led by Chang and reported at a recent professional meeting found that surgeons who learned of a patient's alpha-blocker exposure before cataract surgery and modified their technique had excellent results, according to the advisory.

The three medical associations urged patients to be more forthcoming about their drug therapies when preparing for cataract surgery.

"Very often patients withhold information, thinking...it's unimportant for the ophthalmologist to be aware of their medications," said Samuel Masket, president of the American Society of Cataract and Refractive Surgery. "The other thing is that I think there's a degree of sensitivity about the need for bladder-specific medications, and not everyone feels comfortable divulging that [information], particularly if they don't have any idea that it would have potential bearing on their surgery."

He said a patient's alpha-blocker use is often discovered during cataract surgery, a procedure that does not require the patient to be unconscious.

"I think it's also somewhat cultural," said Masket, who practices in Los Angeles. "As an example, I take care of a large number of Russian males. Virtually every Russian male over a certain age is taking a uro-specific agent. I think they tend to avoid prostate surgery in their community as a rule."

Stopping the alpha-blocker therapy before cataract surgery is not the answer, Chang said.

Not only does stopping the therapy possibly complicate the prostatic condition, he said, but the effect on the iris muscle does not disappear.

"We were very surprised to see that patients who hadn't even taken the drug for one to up to three or even five years can still show this floppy iris problem during surgery," Chang said. "So we now want to know even if patients have taken the drug in the past and are no longer taking it—that is still very pertinent."

—Cheryl A. Thompson