Tamsulosin use linked with postop cataract surgery complications

Ophthalmologists should counsel older male patients with benign prostatic hyperplasia and confer with prescribing physicians.

The use of tamsulosin to treat prostate enlargement and urinary symptoms was linked with an elevated risk of complications after cataract surgery, whereas other alpha-blockers showed no increased risk, according to a study.

Earlier studies linked the use of Flomax (tamsulosin, Boehringer Ingelheim) with intraoperative floppy iris syndrome, which may complicate cataract surgery. The new study was the first to link tamsulosin with postoperative complications, the study authors said.

“It’s not just the increasing difficulty of the surgery that’s associated with the drug, but that the issue is a postoperative one,” Chaim M. Bell, MD, PhD, the corresponding author, told Ocular Surgery News. “It increases the postoperative risk of adverse events.”

The findings showed that ophthalmologists should counsel older male patients with benign prostatic hyperplasia about the potential risks associated with tamsulosin use.

“[The patient with known cataract] should consider a different type of medication other than tamsulosin,” Dr. Bell said. “If you have a cataract and you are anticipating surgery but you also develop [benign prostatic hyperplasia] and require medication for it, you might want to consider an alternative to tamsulosin.”

Also, eye care specialists should prepare for intraoperative complications or refer difficult cases to more experienced surgeons.

“It’s much easier to plan for a difficult surgery as compared to being surprised at the time of surgery, mostly because the planning for the additional surgery might require additional surgical instruments or additional medications to try to overcome the effect of tamsulosin,” he said.

Study results are published in the Journal of the American Medical Association.

Relative risk

Investigators used the Ontario Health Insurance Plan database to identify 96,128 men aged 66 years or older who underwent cataract surgery between April 2002 and June 2007.

They identified 284 patients who had complications within 14 days after surgery. They matched 280 cases with 1,102 controls according to patient age, surgeon and date of cataract surgery. Recent tamsulosin or other alpha-blocker exposure was defined as 14 days or fewer before surgery. Previous exposure was defined as 15 to 365 days before surgery.

Postop adverse events were more common among patients with recent tamsulosin exposure (7.5%) than among controls (2.7%); 7.5% of patients and 8% of controls had recent exposure to other alpha-blockers but did not have a higher incidence of adverse events. Previous exposure to tamsulosin or other alpha-blockers was also not associated with adverse events, the authors said.

Postop complications included retinal detachment, lost lens or lens fragments, or endophthalmitis. Procedures performed 1 to 14 days after cataract surgery included vitrectomy, vitreous aspiration or injection, dislocated lens extraction or air-fluid exchange.

Tamsulosin use was associated with an adjusted risk factor of 2.33 for postop complications; other alpha-blockers had an adjusted risk factor of 0.91. However, the risk associated with other alpha-blockers may be clinically significant, Dr. Bell said. The confidence interval of risk associated with other alpha-blockers ranged from 0.5 to 1.5.

Statistical strengths and weaknesses

To ensure statistical integrity, the authors used tracer analysis, using proton pump inhibitors as a tracer exposure, which was not expected to lead to serious adverse events after cataract surgery.

“We looked specifically at another drug, which we didn’t anticipate to have any relationship to it,” Dr. Bell said. “That was proton pump inhibitors. That showed that there was no difference. It gives us increasing confidence that we didn’t have a biased sample.”

However, the study had some shortcomings. For example, it did not show when cessation of tamsulosin or other alpha-blockers reduced the risk of postop complications, the authors said.

“I think that some of the other literature has looked at stopping the drug before surgery. We couldn’t address that issue,” Dr. Bell said. “If that is being considered, it should be considered in concert with the prescribing physician, and to consider other medications.”

Also, claims data only showed prescriptions that were filled, not those that were used. The authors said they were unable to accurately correlate postop complications and intraoperative findings such as floppy iris syndrome. – by Matt Hasson

Reference:

• Bell CM, Hatch WV, Fischer HD, et al. Association between tamsulosin and serious ophthalmic adverse events in older men following cataract surgery. JAMA. 2009;301(19):1991-1996.

• Chaim M. Bell, MD, PhD, can be reached at St. Michael’s Hospital, 30 Bond St., Toronto, Ontario, Canada M5B 1W8; e-mail: bellc@smh.toronto.on.ca.

That this is the first study on intraoperative floppy iris syndrome (IFIS) to be published in the general medical literature is very important. Coupled with the accompanying Journal of the American Medical Association editorial on IFIS and my own editorial in the June issue of American Family Physician (journal of the American Academy of Family Physicians), this article should produce a much greater awareness among prescribing doctors about tamsulosin’s impact on cataract surgery. The finding that tamsulosin doubled the risk of postoperative complications confirms what ophthalmologists already know about IFIS, particularly since the study encompasses years before the first description of the syndrome. Because the study documents an increase in retinal detachment, lost lens fragments, and severe inflammation or infection, non-ophthalmologists will better grasp the seriousness of IFIS, compared to reading previous studies that list a higher rate of “posterior capsular rupture.” The fact that non-selective alpha-antagonists were not associated with increased complications adds to the body of evidence that tamsulosin is more likely to cause severe IFIS, and this may influence prescribing doctors to consider other alpha-blockers as a first-line treatment.

– David F. Chang, MD
OSN Cataract Surgery Board Member