Common Erectile Dysfunction Drug Linked to Glaucoma, Researchers Say

• A new study suggests that people who take the erectile dysfunction drug Cialis for urinary tract issues may have a higher risk of glaucoma, a vision-threatening eye disease.
• Men who take tadalafil and have glaucoma risk factors should receive regular eye exams, the researchers say.
• The overall risk of eye disease from occasional use of Cialis to treat erectile dysfunction is low.

A commonly prescribed erectile dysfunction drug may raise the risk of glaucoma for males with an enlarged prostate who take the medication, according to a new study.

Researchers say that men taking the medication tadalafil, which is sold under the brand name Cialis, on a long-term basis to treat urinary urgency and urinary frequency associated with an enlarged prostate could have a higher likelihood of developing glaucoma, a serious eye condition that can affect vision.

The researchers suggest that people taking tadalafil on a daily basis over a long period of time have regular eye exams, particularly men who already have glaucoma risk factors. These include a family history of the disease or already having ocular hypertension, a condition that causes elevated pressure inside the eye.

They recently published their findings in the British Journal of Ophthalmology.

S. Adam Ramin, MD, a urologist, urologic oncologist, and medical director of Urology Cancer Specialists in Los Angeles, said Cialis has been prescribed for years to help urinary tract issues.

He said the risk of glaucoma is still low, but it is something patients should be aware of.

“The risk is relatively small, but it’s important to discuss this with patients,” Ramin told Healthline.

He added that males who occasionally take Cialis to treat erectile dysfunction should not be concerned because they aren’t using the medication on a daily basis.

Craig Comiter, MD, a professor of urology at Stanford University, agreed that the risks are low.

“It’s important to note that the absolute risk was less than 1% greater with daily tadalafil,” he told Healthline. 

“For certain, someone with a family history or pre-existing glaucoma or other risk factors should be monitored with ophthalmologic care,” he added. “It’s not obvious that taking this drug changes the required monitoring.”

Officials at Eli Lilly and Company, the manufacturers of Cialis, did not respond to a request for comment on the new research.

How erectile dysfunction drugs may cause vision problems

Tadalafil belongs to a class of medications known as phosphodiesterase type 5 inhibitors (PDE5i).

This group also includes sildenafil, which is sold under the brand name Viagra.

According to the American Academy of Ophthalmology, erectile dysfunction drugs, such as tadalafil and sildenafil, may cause relatively minor vision problems such as light sensitivity, blurry vision, a blue-green tint to vision, and decreased color vision.

For their new study, researchers analyzed medical records from the TriNetX Analytics Network of more than 70,000 males ages 40 and older. None of the participants had a history of glaucoma.

Between January 2012 and December 2022, half of the subjects received tadalafil for urinary tract symptoms for up to 5 years. The other participants were taking the drug.

The researchers compared the two groups over five years, examining the likelihood of the participants developing glaucoma or ocular hypertension, or if they began treatment for glaucoma.

The analysis found that males who were prescribed tadalafil were 22% more likely to develop glaucoma than those who had not received the drug.

Males who took tadalafil were also 32% more likely to develop ocular hypertension, 33% more likely to develop primary open-angle glaucoma, and 33% more likely to begin glaucoma treatment.

The researchers noted that most of the study participants were white, which might limit how confidently the findings can be applied to men from other ethnic backgrounds.

They added that their research was observational, so it cannot demonstrate that tadalafil itself caused the increased eye risks.

Ramin said that the risks to any individual patient are relatively small, especially for someone who doesn’t use tadalafil for extended periods.

He added that are medications that aren’t PDESi drugs that can be used to treat urinary tract issues.

“There are alternatives,” Ramin said.

“There are multiple treatments for lower urinary tract symptoms associated with benign prostatic enlargement,” added Comiter. “All patients should be treated with behavioral modification and, if indicated, can try different classes of pharmacotherapy.”

“Each of these medications has their own side effect profile and, based on a patient’s history and risk factors for concomitant disease, the patient and physician should exercise shared decision-making and figuring out the best pharmacologic treatment,” he said.

“If pharmacologic treatment is either unsuccessful or contraindicated, surgical intervention is often successful,” Comiter noted.

What to know about glaucoma

Glaucoma is a condition generally caused by abnormally high pressure inside the eye.

The pressure can cause damage to the optic nerve, in particular eroding optic nerve tissue. That erosion can lead to vision loss and even blindness.

The most common form of glaucoma is open-angle glaucoma.

There are usually no symptoms in the early stages of this type of glaucoma except for a gradual loss of vision.

The vision loss, in fact, may occur so slowly that a person may not experience any other symptoms or signs of this damage before it becomes permanent and vision loss cannot be restored.

More than 4 million people in the United States are estimated to have glaucoma. About half are unaware they have the condition.

About 80 million people worldwide have glaucoma. It is a leading cause of blindness globally.

However, in the United States, blindness rarely occurs from glaucoma due to early detection and advanced treatments.

Glaucoma can affect people of any age, but people over the age of 60 are at higher risk. So are African-Americans, people with diabetes, and people with severe nearsightedness.

There is no cure for glaucoma, but treatments can slow or even halt the progression of the condition. Treatments for glaucoma include:

• medications, including tablets and eye drops
• laser treatment to reduce eye pressure
• surgery to help drain fluid buildup behind the eye

Ramin said it’s important for people to get regular eye exams so they can have their eye pressure tested for signs of glaucoma.