Alpha-blocker, iris syndrome link still a concern

Tamsulosin is the most commonly prescribed medication for the treatment of BPH, according to the American Society of Cataract and Refractive Surgery (ASCRS), which conducted the survey. The drug is selective for the alpha-1A receptor subtype, which is predominant in the prostate and also in the iris dilator smooth muscle. Alpha-blockers, however, have been linked to intraoperative floppy iris syndrome (IFIS), which manifests itself as poor pupil dilation before cataract surgery, billowing and prolapse of the iris, and progressive miosis during the surgery.

Approximately 52% of respondents to the survey reported experiencing significant iris damage that was higher in patients with IFIS than in patients without IFIS during the 2 years preceding the survey, and 24% said that the rate of posterior capsule rupture they saw in patients with IFIS was higher than the rate in non-IFIS patients during the 2 years preceding the survey, according to David F. Chang, MD, chairman of the ASCRS Cataract Clinical Committee.

When asked whether IFIS is more likely to occur with tamsulosin or with a non-selective alpha-1 blocker, 21% of survey respondents said that they did not have enough experience to answer the question. Of those with an opinion, however, more than 90% expressed a belief that IFIS is more likely to happen with tamsulosin than with a non-selective alpha-1 blocker.

IFIS also has been associated with non-selective alpha-1 blockers such as alfuzosin hydrochloride (Uroxatral), doxazosin mesylate (Cardura), and terazosin HCl (Hytrin), but several studies suggest that the complication is more likely to occur with tamsulosin than with the non-selective agents, according to the ASCRS Cataract Clinical Committee.

Another survey question asked ophthalmologists whether they would take tamsulosin if they had BPH and mildly symptomatic cataracts. Twenty-three percent of respondents said they would avoid all alpha-blockers if possible, 23% said they would undergo cataract surgery first, and 17% said they would take a non-selective alpha-blocker instead of tamsulosin. The remaining 37% said they would take tamsulosin if it was recommended.

Educational initiative launched

Results of the survey prompted ASCRS and the American Academy of Ophthalmology (AAO) to join with the American College of Physicians (ACP) and the American Academy of Family Physicians (AAFP) to launch an educational initiative aimed at primary care physicians, said Dr. Chang, who is clinical professor of ophthalmology at the University of California, San Francisco.

Most urologists already are aware of IFIS, he added, but urologists often do not see patients with BPH until the condition fails to respond to medical therapy. Most new prescriptions for alpha-blocker treatment of BPH or hypertension, Dr. Chang said, are written by primary care physicians, and knowledge of the alpha-blocker/IFIS connection is not as widespread among general practitioners and their patients as it is among ophthalmologists and urologists.

In 2006, AUA partnered with ASCRS and AAO raise awareness about IFIS. That initiative was largely directed at urologists, and AUA sent a press release to all members alerting them to the potential complication.

The more recent statement says, in part: "In a patient with a known diagnosis of cataract, prescribing physicians may wish to consider involving the patient's cataract surgeon prior to initiating nonemergent, chronic tamsulosin or alpha-blocker treatment. Options might include an eye exam or having either the patient or the prescribing MD communicate with the cataract surgeon. Patients should also be encouraged to report any prior or current history of alpha-1 antagonist use to their ophthalmic surgeon prior to undergoing any eye surgery."