Study Finds Tadalafil Use Linked to Higher Glaucoma Risk

A Taiwanese analysis of health records has identified a statistically significant association between long-term use of tadalafil, the active ingredient in the erectile-dysfunction drug Cialis, and the incidence of glaucoma. The study compared nearly 37,000 men over age 40 who were prescribed tadalafil for lower urinary tract symptoms with a matched group of non-users and found a 22% higher risk of glaucoma over a five-year period, as well as an elevated risk of ocular hypertension.

The authors of the paper, published in the British Journal of Ophthalmology, recommend that clinicians consider regular eye examinations for patients on tadalafil, especially those with existing glaucoma risk factors. > "Ophthalmic evaluation and follow-up may be considered, particularly in patients with risk factors for glaucoma," the researchers wrote.

Tadalafil belongs to a class of phosphodiesterase type 5 inhibitors (PDE5is) originally developed for cardiovascular conditions but now widely used for erectile dysfunction and urinary-tract symptoms associated with an enlarged prostate. While generally regarded as safe, prior studies have hinted at possible visual side effects, though such events remain uncommon.

In the current cohort, 3.93% of men over 50 taking tadalafil developed glaucoma, compared with 3.16% of non-users, a 0.77 percentage-point absolute increase. The investigators note that further research is needed to clarify the mechanisms linking PDE5is to optic-nerve damage.

The findings suggest that physicians should weigh the modest ocular risk against the therapeutic benefits of tadalafil, and that patients with pre-existing eye conditions may require closer monitoring.