A 31-year-old man showed up at a New York urgent care clinic, complaining of problems with his vision — which had been tinted red for two days.
The culprit? An erectile dysfunction medication that he bought online, according to a case report published this week in the journal Retinal Cases.
The man took a very high dose of sildenafil citrate, which is sold under the brand name Viagra as well as in generic forms. He took the drug in a liquid form, drinking directly from the bottle rather than using the measuring pipette provided, according to the case report. He didn’t know how much he had taken, but guessed that it was much higher than the recommended amount.
“A short while after ingesting the substance, the patient began to notice a red tint to his vision,” reads the report. Visual changes are a known potential side effect of sildenafil citrate at the approved dose, but generally resolve within 24 hours.
In this case, the man’s vision was as sharp as it always was, and his pupils still reacted to light. But, he saw everything with a red tinge. He was given several medications to try to treat the redness problem, but none seemed to have an effect. More than a year later, the problem remained.
According to the researchers, the man suffered damage to the cone receptors in his retina, which are responsible for colour vision. While eye problems are a potential side effect of the drug, they also note that because it was bought online, it may have been contaminated with some other substance as well or been at a higher-than-expected concentration.
Still, they wanted to let people know that high doses of Viagra or sildenafil citrate can cause permanent damage.
“People live by the philosophy that if a little bit is good, a lot is better. This study shows how dangerous a large dose of a commonly used medication can be,” said lead investigator Dr. Richard Rosen, director of retina services at the New York Eye and Ear Infirmary of Mount Sinai, in a press release.
“People who depend on colored vision for their livelihood need to realize there could be a long-lasting impact of overindulging on this drug.”