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On call: Viagra and vision

On call

Viagra and vision

Q. My wife and I have recently been reassured that Viagra is safe for my heart. But a new worry has emerged: Is it safe for my eyes?

A. Because Viagra (sildenafil) is so familiar to nearly all Americans, it’s easy to forget that it is a relatively new drug. Viagra was approved by the FDA in March 1998, and the other erectile dysfunction (ED) pills are even newer; Levitra (vardenafil) was approved in August 2003 and Cialis (tadalafil) in November 2003.

It can take time for adverse reactions to gain recognition, particularly if they are uncommon, and it is important for doctors, patients, drug companies, and regulatory agencies to remain vigilant. But millions of men have used ED pills, which have received attention and scrutiny afforded few drugs. A large body of evidence tells us that the ED pills are safe for the heart except for men taking nitrate medications in any form and for those with serious, unstable cardiovascular disease or uncontrolled hypertension. Alpha blockers also call for caution, especially in men considering Levitra or Cialis.

The ED pills are designed to widen arteries in the penis, bringing more blood into the obdurate organ to promote firm erections. But these medications can affect arteries elsewhere in the body. That’s why some men experience headaches, facial flushing, nasal congestion, nausea, or diarrhea, and it’s also the reason doctors are experimenting with these drugs for strokes and other problems. In fact, the FDA has just approved sildenafil for a rare but serious lung disease, pulmonary hypertension; it will be marketed as Revatio for this purpose.

Visual problems were recognized at the very outset of the Viagra era. A few men who take ED pills develop visual disturbances, typically in the form of impaired color vision or a bluish haze. Like the more common side effects, these visual problems are mild and temporary. But since 1998, men with retinitis pigmentosa, a rare eye disease, have been cautioned about possible harm from Viagra.

New information has added another rare eye disease to the worry list. Nonarteritic anterior ischemic optic neuropathy (NAION) is a poorly understood disorder that can cause blindness. In March 2005, doctors reported that seven men experienced visual impairment within hours of using Viagra. As of summer 2005, additional cases have been reported to the FDA. Fortunately, fewer than 50 cases are being investigated, compared to the millions of men that have used ED pills without problems.

It’s not clear that there is a cause-and-effect relationship between ED pills and NAION. At present, the concern is not great enough to prevent men who need ED pills from using them. But the new worry should remind all men over 50 to get regular eye care, and it should emphasize that ED pills are serious medications. You should not use them unless you really need them, and if you use them, you should remain alert for possible side effects. Above all, you should get these medications from a doctor who knows you well and can advise you on their use, not from the guy at the next locker or the “doctor” on the Internet.

— Harvey B. Simon, M.D. Editor, Harvard Men’s Health Watch

Last updated:	August 21, 2006