Long-term tadalafil use linked to higher risk of glaucoma, study finds

Men who use tadalafil (Cialis) for lower urinary tract symptoms may face an increased risk of glaucoma, according to a study published in the British Journal of Ophthalmology. Researchers examined anonymized health records of 73,854 men aged 40 and older, half of whom had been prescribed tadalafil or another phosphodiesterase-5 inhibitor for up to five years. Over a five-year follow-up, tadalafil users were 22% more likely to develop glaucoma, 32% more likely to develop ocular hypertension, and about one-third more likely to begin treatment for primary open-angle glaucoma.

The analysis matched participants on variables such as age, ethnicity, smoking status, cardiovascular disease and other health conditions to reduce bias. Elevated risks persisted across sub-groups, including men aged 50 and older and those with various comorbidities. The authors note that the observational design cannot prove causation and that medication adherence and changes over time were not captured. They also acknowledge that the majority of participants were White, limiting generalizability.

"These findings suggest that chronic PDE5 inhibition may influence ocular physiology, warranting further mechanistic investigation," the researchers wrote.

"These findings do not contraindicate tadalafil use but highlight the importance of baseline ophthalmic assessment and regular follow-up, particularly in patients with pre-existing glaucoma, ocular hypertension, a family history of glaucoma, high myopia, or those requiring long-term therapy," they added.

The study was funded by Taichung Veterans General Hospital in Taiwan.