A popular drug used to treat erectile dysfunction and symptoms of an enlarged prostate may increase the risk of a serious eye disease that can lead to blindness.
Tadalafil, the active ingredient in the brand-name erectile dysfunction drug Cialis, may be linked to an increased risk of glaucoma, a serious eye condition that can cause gradual vision loss.
Researchers analyzed the health records of nearly 74,000 men aged 40 and older with lower urinary tract symptoms.
In addition to erectile dysfunction, tadalafil is also used to treat symptoms of benign prostatic hyperplasia (BPH) or an enlarged prostate, to relieve urinary symptoms such as difficulty urinating, weak urine flow, and frequent urination.
The study, published in the British Journal of Ophthalmology, compared men who were prescribed the drug with men who did not take it and followed them for five years to determine whether they had developed glaucoma, or increased pressure in the eye, which can also lead to vision problems.
Researchers found that men who used tadalafil were 22 percent more likely to develop glaucoma than men who did not use the drug.
In addition to erectile dysfunction, tadalafil is also used to treat symptoms of benign prostatic hyperplasia (BPH) or an enlarged prostate (stock image)
They also found that men who took the medication were 32 percent more likely to develop high pressure in the eye and 33 percent more likely to develop primary open-angle glaucoma, the most common type of glaucoma.
Glaucoma is a group of eye diseases that damage the optic nerve. It usually occurs due to a buildup of fluid and pressure in the eye. If left untreated or severe, it can lead to permanent vision loss and blindness.
Based on the findings, the study authors concluded that men taking the drug should undergo an ophthalmological examination and follow-ups.
The study did not posit why tadalafil might increase the risk, but it could be because it changes blood flow to the optic nerve.
Tadalafil dilates blood vessels and lowers blood pressure. While this helps with circulation when it comes to erectile dysfunction, it can reduce blood flow to the optic nerve at critical times.
In addition, a change in blood flow to the blood vessels in the eye can increase eye pressure, although this connection is less studied.
The study was observational and researchers did not conclude that tadalafil causes glaucoma, but only that its use may be associated with an increased risk of eye disease, especially in people with pre-existing risk factors.
These risk factors include already having glaucoma or increased eye pressure, having another type of optic nerve disease, and having a family history of the eye disease.
