The human vision changes after taking a drug against erectile dysfunction

NEW YORK – A man's vision changed dramatically after taking a sip of a drug he bought online that was commonly used to treat erectile dysfunction.

According to a case report published this month, the 31-year-old would have bought an unspecified form of sildenafil citrate – the same active ingredient in Viagra – from an online "non-pharmaceutical source". light in both eyes, and his vision became tinged with red.

His doctors do not know how much he took, "but we think the dose was well above the recommended dose," the authors wrote.

The lightning soon subsided, but the red distribution through his vision was not.

"It's important to remember that you need to use drugs at the right doses. Sildenafil is extremely safe at the usual doses, "said Dr. Raj Maturi, ophthalmologist, associate professor at the University of Indiana's School of Medicine, who practices at the Midwest Eye Institute. Maturi was not involved in the new report, although he did study the effects of sildenafil on the eyes.

"We did not find any real problem. In fact, zero cases that look like this. Some patients had blurred vision, but the disease almost disappeared within hours, "said Maturi, also spokesman for the American Academy of Ophthalmology. "However, this is quite possible if the dose that is taken is maybe four or five, maybe even 10 times the normal dose."

Although rare, sildenafil is known to cause temporary visual changes such as color changes, blurring, or loss of vision, according to the US National Library of Medicine. These symptoms usually disappear in a day. in rare cases, they were permanent, although it was not always clear whether the drug itself was to blame.

According to Maturi, when patients have visual symptoms after taking sildenafil, there is often something else to play. For example, when the drug is taken with drugs for hypertension, the blood pressure may drop to the point that "there is not enough blood in the optic nerve", which causes a transient loss of vision.

The report's findings suggest that the drug was toxic to light-sensitive human eye cells.

In order to treat erectile dysfunction, sildenafil acts on an enzyme of the penile tissues. But a similar enzyme exists in the eye. Drugs such as Cialis and Levitra and, to a lesser extent, Viagra, may have a lesser effect, said Maturi.

The authors of the new document also recognize that there is some uncertainty as to the exact nature of the bottle that the man ordered on the Internet. "The purity of the active substance and the precision of the concentration are of concern," they wrote.

Maturi said it was a warning against buying drugs on some websites because they might contain unknown ingredients that increase their potency and have unwanted side effects. "The good news is that these drugs are relatively inexpensive," he added, in generic forms in pharmacies.

"Companies using the Internet do different things that are absolutely not approved by the FDA and put patients in trouble," he said.