Tadalafil Long-Term Use Linked to 22% Higher Glaucoma Risk in Men with Enlarged Prostates
核心洞察
A large observational study of 73,854 men found tadalafil users had a 22% higher risk of developing glaucoma (搜索) compared to non-users over five years.
Men prescribed tadalafil were also 32% more likely to develop ocular hypertension (搜索) and 33% more likely to initiate glaucoma (搜索) treatment.
Researchers emphasize the findings do not contraindicate tadalafil use but highlight the importance of baseline ophthalmic assessment and regular eye monitoring.
Men who take the erectile dysfunction drug tadalafil (Cialis) long-term for lower urinary tract symptoms associated with an enlarged prostate may face a significantly higher risk of developing glaucoma (搜索), according to a large comparative study published online in the British Journal of Ophthalmology.
The research, which analyzed anonymized data from 73,854 men aged 40 and older in the TriNetX Analytics Network, found that those prescribed tadalafil were 22% more likely to develop glaucoma (搜索), 32% more likely to develop ocular hypertension (搜索), and 33% more likely to develop primary open-angle glaucoma (搜索)—the most common form of the disease—compared to men who had not been prescribed the drug. Men on tadalafil were also 33% more likely to start glaucoma treatment within the five-year study window.
"This is the first cohort study to show there is a correlation between taking these medications and an increased risk of developing glaucoma (搜索)," said Flora Hui, an optometrist and research fellow at the Centre for Eye Research Australia, who was not involved in the study.
Study Design and Population
The researchers, led by a team from Taiwan, drew on data spanning January 2012 to December 2022. They matched 36,927 men prescribed tadalafil or another phosphodiesterase type 5 (搜索) inhibitor (PDE5i) with an equal number of men who had not received these drugs. The two groups were paired based on shared characteristics including age, ethnicity, smoking status, alcohol-related disorders, and underlying conditions such as cardiovascular disease, diabetes, cancer, high cholesterol, kidney function, obesity, and chronic obstructive pulmonary disease.
The analysis focused specifically on tadalafil prescribed for the management of lower urinary tract symptoms associated with benign prostatic hyperplasia (搜索)—an indication that typically involves long-term daily dosing, as opposed to the as-needed use common for erectile dysfunction.
Risk Patterns and Subgroup Findings
Further in-depth analysis revealed that the associations held true among men who developed glaucoma (搜索) within one, three, or six months of starting tadalafil treatment. The elevated risk was consistently observed among patients aged 50 and older, those of White ethnicity, and those with various underlying conditions included in the study.
"The findings suggest that chronic PDE5 inhibition may influence ocular physiology, warranting further mechanistic investigation," the researchers wrote.
Potential Mechanisms and Clinical Context
Tadalafil belongs to the PDE5i class of drugs, which also includes sildenafil (Viagra). These agents block the PDE-5 protein, increasing blood flow to the penis and relaxing muscle tissue in organs such as the prostate and bladder. Previous studies have linked PDE5i drugs with various ophthalmological side effects, including conditions affecting the optic nerve and the macula, but evidence connecting them specifically to glaucoma (搜索) had been patchy and inconclusive.
Dr. Hui explained one working theory: "If you're getting transient episodes where you don't get sufficient blood to the nerve, then that can increase the chance of injury to the nerve and then potentially increase your risk of developing glaucoma (搜索)."
Andrew White, a clinician scientist ophthalmologist at Westmead Hospital and the Westmead Institute for Medical Research, who also did not contribute to the study, noted that some people experience temporary increases in eye pressure while others experience low blood pressure. "One of the other things that we have known for quite a long time is that if your blood pressure is too low or your blood pressure control varies a lot, then your glaucoma (搜索) can also get worse," he said.
Study Limitations
As an observational study, the research cannot establish causation. The authors acknowledged several limitations: they could not account for changes in medication prescription and use over time, nor the development of additional underlying conditions. Most study participants were White, meaning the findings may not generalize to men of other ethnic backgrounds.
Dr. Hui also noted that approximately 40% of participants had high blood pressure and 40% had high cholesterol. "It's a bit inconclusive about whether the additional chronic conditions made a difference," she said.
Clinical Recommendations
Despite the findings, the researchers stressed that the results "do not contraindicate tadalafil use but highlight the importance of baseline ophthalmic assessment and regular follow-up, particularly in patients with pre-existing glaucoma (搜索), ocular hypertension (搜索), a family history of glaucoma, high myopia, or those requiring long-term therapy."
Dr. Hui echoed this sentiment: "It's sometimes not the first thing we think about when we're taking these medications, but it's really important to get tested before you're starting these medications and if you are currently on them to get regular eye checks as well."
Professor White added that good monitoring and early intervention could improve outcomes: "If there is a reason for you to be monitored more closely, your local optometrist is a great start. And the sooner we can pick something up, the sooner we can get on with treatment."
For many patients, Dr. Hui noted, erectile dysfunction drugs can greatly improve quality of life, and the decision about potential risks and benefits remains something each patient should weigh with their doctor.