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Alpha-blockers call for modification in cataract surgery

by Medindia Content Team on Aug 23 2006 12:03 PM

The risk of post-operative problems in cataract surgery is higher in patients who have taken alpha-blocker drugs like Flomax to treat an enlarged prostate.

According to the 3 medical associations; The American Academy of Ophthalmology, the American Society of Cataract and Refractive Surgery and the American Urological Association, mentioning the use of drugs like Flomax (tamsulosin), Hytrin (terazosin), Cardura (doxazosin) or Uroxatral (alfuzosin) or any other drug categorized as an alpha-blocker can allow surgeons to alter their technique during the cataract surgery and avoid complications seen in such patients.

However, according to representatives from these medical associations said that there is no proof that these drugs can cause any long-term harm or vision loss. Patients with cataract need not stop the medications before having the surgery. It is just that the surgical procedure will be altered accordingly.

"You don't need to worry; you just need to inform your eye surgeon if you are currently taking, or have ever taken, Flomax or other alpha-blockers," said Dr. David F. Chang, clinical professor of ophthalmology at the University of California, San Francisco, School of Medicine.

Dr. Chang and Dr. John Campbell studied 1,600 patients who were using or had used Flomax or other alpha-blockers previously. These alpha-blockers seemed to restrain the muscle of the iris, from allowing the pupil to remain completely open during cataract surgery with conventional eye drops. This dilation is essential for the removal of the clouded, cataract-covered lens below the pupil and replacement with an artificial one.

Chang reported that the use of alpha-blocker may cause the pupil to suddenly constrict during surgery, causing the iris to relax. This condition was termed as "intraoperative floppy iris syndrome" by Chang and Campbell.

" This doesn't cause any eye disfigurement, but it can increase the risk of the surgeon tearing a portion of the eye that holds the artificial lens in place, Chang said.

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"If we know that patients have ever used Flomax or the other drugs, we can use different, longer-lasting dilation eye drops or micro-hooks to keep the pupil completely dilated during surgery," Chang said. "Taking these measures, which eye surgeons normally wouldn't use, will prevent potential problems and result in an excellent prognosis. The issue is that when the pupil isn't completely dilated, surgeons just can't see what they're doing as well."

The medical associations jointly released a patient advisory on Aug. 22, based on the findings. Chang warned eye surgeons about drug-related problems during cataract surgery by e-mail alert, which was started by him last year.

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The U.S. Food and Drug Administration approved a label change in November 2005, for the alpha-blockers that read, "The patient's ophthalmologist should be prepared for possible modifications to their surgical technique." It now finds a place in patient information material for Flomax.

Boehringer Ingelheim Pharmaceuticals Inc., maker of Flomax, has also sent letters to ophthalmologists and urologists about the possible complications during cataract surgery, according to the spokeswoman for that company, Kate O'Connor.

A cataract is a sight-affecting problem. The lens in the eye gets clouded and this increases with age. Cataracts usually begin to develop after the age of 50 and, by the age of 80, more than half of all Americans either have a cataract or have had cataract surgery.

An enlarged prostate, or benign prostatic hyperplasia (BPH), is also an age related problem.50% of the men are affected by the age of 60 and around 90% are affected by the age of 70 years. Urination difficulty such as a weak stream, dribbling after urination, a feeling the bladder is not completely empty, and frequent overnight bathroom visits is brought about by this problem. Alpha-blockers help control the need for sudden and frequent urination, especially at night. They bring about this by controlling a receptor in the prostate muscle. Usually, men take these drugs, though they are sometime prescribed to some women for urinary retention.

The dilation muscle in the iris and pupil is controlled by the same receptor, according to Chang. The sudden pupil dilation during surgery can be caused by any alpha-blocker but research shows that it is usually from the use of Flomax, since it does not cause dizziness even if the patient gets up too quickly.


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