Erectile Dysfunction Drugs Linked to Vision Loss
NAION occurs because blood flow to the optic nerve is disrupted. It is about 6 times more common than arteritic anterior ischemic optic neuropathy (AAION), a type of inflammatory arteritis. 3 NAION affects roughly 1 in 50 000 to 1 in 10 000 white people over the age of 50 every year (data are unavailable for other races). 3 The cause of NAOIN is unknown, and it is unclear why a vasodilator might cause such vascular damage. Animal models are lacking. Other medications associated with NAION include sumatriptan, amiodarone and nasal decongestants. 3
Viagra & Cialis Don’t Cause Eye Damage
Erectile dysfunction (ED) drugs, specifically Viagra (sildenafil citrate, Pfizer) and Cialis (tadalafil, Lilly), cause no vision problems or retinal abnormalities, at least over a six-month period, according to a study in Aprils Archives of Ophthalmology .
ED drugs are known as selective phodiesterase type 5 (PDE5) inhibitors because they treat erectile dysfunction by interfering with the action of the compound PDE5 on the blood vessels in the penis.
However, PDE5 inhibitors may also act on similar compounds in the retina. Mild and transient blurred vision, blue-tinged vision and altered light perception have been reported by men taking these drugs, and some visual complications of long-term use have been reported. Cases of nonarteritic anterior ischemic optic neuropathy (NAION), central serous chorioretinopathy and vascular events have also been linked to ED drugs.
Visual side effects probably occur as a consequence of off-target inhibition of PDE6, which is structurally similar to PDE5 and is involved in regulating phototransduction, the authors say. Visual effects of PDE5 inhibitors are typically mild and transient. However, visual complications of long-term use have been suggested, the authors add. These have been infrequent and of unclear cause because many men who use PDE5 inhibitors have comorbid diseases that predispose them to visual complications, they say.
To further understand the safety of these drugs, researchers at Lilly Research Laboratories, of Eli Lilly and Company, conducted a randomized placebo-controlled study to assess changes in the retina among men taking tadalafil or sildenafil. In the study, 244 male subjects between the ages of 30 to 65 were randomized to take a placebo, 5mg of tadalafil or 50mg of sildenafil daily for six months. Study participants were healthy or had mild erectile dysfunction and had no baseline ophthalmologic abnormalities or risk factors for eye problems.
The results: Among the 194 men (79.5%) who completed the study, no significant differences were found between treatment and placebo groups on electroretinography, visual function tests, measurements of IOP or assessments of the anatomy of the eye.
Our results indicate that there is no cumulative damage or effect of clinical significance for either 5mg of tadalafil or 50mg of sildenafil taken daily for six months, they conclude.
Cordell WH, Maturi RK, Costigan TM, et al; ERG Testing During Chronic PDE5 Inhibitor Administration (ERG-PDE5i) Consortium. Retinal effects of 6 months of daily use of tadalafil or sildenafil. Arch Ophthalmol 2009 Apr;127(4):367-73.
Erectile Dysfunction Drugs Linked to Vision Loss
Routine use of drugs like Viagra is associated with an increased risk of developing several types of eye problems that can lead to sudden vision loss and blindness, a new study suggests.
Older men who regularly use erectile dysfunction drugs may be more likely to develop serious side effects that can lead to vision loss and blindness, a new study suggests.
Some isolated case reports and small studies have previously linked erectile dysfunction drugs to serious vision-related side effects. These include retinal detachment, when the retina lifts away from the back of the eye; retinal vascular occlusion, when clots block veins in the eye; and ischemic optic neuropathy, when blood stops flowing to the optic nerve. These conditions can come on suddenly, and lead to permanent vision loss if they aren’t treated quickly.
For the new study, researchers wanted to assess the risks seen in these smaller studies by examining a much larger group of men over an average follow-up period of about four years. They analyzed health insurance claims data on more than 213,000 men who received new prescriptions for one of four erectile dysfunction drugs in a family of medicines known as phosphodiesterase type 5 inhibitors (PDE5Is): sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra, Staxyn), and avanafil (Stendra). The analysis compared eye-related side effects for men who used these drugs with men who did not.
Overall, men who regularly used erectile dysfunction drugs were 85 percent more likely to develop serious vision-related side effects than men who didn’t take these medicines, researchers report in JAMA Ophthalmology.
When researchers looked at each type of ocular side effect in isolation, they found regular erectile dysfunction drug use associated with a 2.8 times greater risk of serious retinal detachment, a doubled risk of ischemic optic neuropathy, and a 44 percent increased risk of retinal vascular occlusion.
“The findings suggest individuals who regularly use PDE5Is need to be cognizant of ocular adverse events associated with these drugs and alert their physicians if they experience any visual deficits,” the researchers concluded.
Researchers defined regular erectile dysfunction drug use as filling at least one prescription every three months. One limitation of the study is that this only told researchers how often men picked up bottles of pills, not how often men actually used the pills.
The study also wasn’t a controlled experiment designed to prove whether or how erectile dysfunction drugs might directly cause eye-related side effects.
There are, however, some plausible explanations for why the drugs might cause these side effects, Brian VanderBeek, MD, MPH, and Maureen Maguire, PhD, of the department of ophthalmology at the University of Pennsylvania in Philadelphia, wrote in an editorial accompanying the study.
For example, ischemic optic neuropathy can develop in people who have unusually low blood pressure at night, the editorial authors write. Erectile dysfunction drugs are often used at night, and are known to lower blood pressure, they note.
In addition, erectile dysfunction drugs can cause thickening of tissue in the middle layer of the wall of the eye, a condition that is associated with retinal detachment, the editorial authors point out. The possible mechanisms for these drugs to cause retinal vascular occlusion aren’t as clear, they write, but it’s possible these medicines might have a negative effect on blood flow within the eyes.
Visual loss with erectile dysfunction medications
Reason for posting: Phosphodiesterase type 5 (PDE5) inhibitors, including sildenafil (Viagra), tadalafil (Cialis) and vardenafil (Levitra), are drugs used to treat erectile dysfunction that have long been recognized to cause temporary, minor visual changes in less than 10% of users. 1 However concerns were raised in 2005 after a small case series was published describing several sildenafil users who experienced sudden, severe visual loss. Health Canada recently issued a warning that the condition known as nonarteritic ischemic optic neuropathy (NAION; see Box 1 ) has been reported in users of all the PDE5 inhibitors. 2
The drugs: PDE5 inhibitors cause smooth-muscle relaxation in the cavernosal arteries, allowing penile vasodilation and erection in response to sexual stimuli. Sildenafil is also used in some patients with pulmonary hypertension because of the drug’s vasodilatory properties. PDE5 inhibitors, particularly sildenafil, cause minor visual changes (e.g., increased perception of light, blurred vision and distorted blue–green colour perception) that are transient, dose-related and likely due to cross-inhibition of retinal PDE6. As of June 2006, Health Canada received 5 domestic reports of NAION associated with PDE5 inhibitor use, but dozens of cases have been reported internationally.
NAION occurs because blood flow to the optic nerve is disrupted. It is about 6 times more common than arteritic anterior ischemic optic neuropathy (AAION), a type of inflammatory arteritis. 3 NAION affects roughly 1 in 50 000 to 1 in 10 000 white people over the age of 50 every year (data are unavailable for other races). 3 The cause of NAOIN is unknown, and it is unclear why a vasodilator might cause such vascular damage. Animal models are lacking. Other medications associated with NAION include sumatriptan, amiodarone and nasal decongestants. 3
Although clinical details are unavailable for many of the suspected cases, the majority of affected users of PDE5 inhibitors appear to have risk factors for NAION ( Box 1 ), particularly atherosclerotic risk factors. 1 They are typically between the ages of 50 and 69, and although causality cannot be proven, visual symptoms typically develop within 6–36 hours after use of the drugs. 4
What to do: Patients should be warned of this very rare but potentially serious and often irreversible adverse effect. Patients with many vascular risk factors (who may also be more likely to have erectile dysfunction) may be at greatest risk. It is not yet clear whether the background population rate of NAION is lower than that seen among PDE5 inhibitor users. The drugs should not be prescribed to people with previous NAION. If symptoms of NAION occur, use of the drug should be stopped and urgent ophthalmologic attention sought. Patients presenting with NAION should be questioned about any history of PDE5 inhibitor use.
REFERENCES
1. Fazio L, Brock G. Erectile dysfunction: management update [review]. CMAJ 2004;170(9):1429-37. [PMC free article] [PubMed]
2. Association of the erectile dysfunction medications Cialis (tadalafil), Levitra (vardenafil hydrochloride) and Viagra (sildenafil citrate) with visual problems [Dear Health Care Professional letter]. Ottawa: Health Canada; 2006 June 19. Available: www.hc-sc.gc.ca/dhp-mps/medeff/advisories-avis/prof/2006/cialis_levitra_viagra_hpc-cps_e.html (accessed 2006 Jul 21).
3. Hellstrom WJG, Kendirci M. PDE-5 inhibitors and NAION. Medscape Urology 2005;6(2). Available: www.medscape.com/viewarticle/508658 (accessed 2006 July 21).
4. Alert for healthcare professionals: sildenafil citrate (marketed as Viagra). Rockville (MD): US Food and Drug Administration; July 2005. Available: www.fda.gov/cder/drug/InfoSheets/HCP/sildenafilHCP.htm (accessed 2006 July 21).
Articles from CMAJ : Canadian Medical Association Journal are provided here courtesy of Canadian Medical Association
Erectile Dysfunction Drugs Such as Viagra, Cialis May Increase Risk of Retinal Detachment and Other Eye Damage
A new study says men using erectile dysfunction medication can develop serious eye problems, including retinal detachment.
The research, led by Mahyar Etminan, PharmD, an associate professor in the Department of Ophthalmology and Visual Sciences at the University of British Columbia, was conducted using data obtained from the PharMetrics Plus database from 2006 to 2020.
The study was published in JAMA Ophthalmology. The participants consisted of 213,000 men who took erectile dysfunction (ED) medication, including sildenafil, tadalafil, vardenafil, and avanafil.
“Mechanistically, studies have found that PDE5Is may be associated with compromised perfusion of the optic nerve,” the study authors wrote. “Moreover, it is postulated that the choroid blood vessels can undergo smooth muscle relaxation through a cyclic guanosine monophosphate pathway that can lead to choroidal congestion.”
The authors noted that in 2020 there were 20 million monthly prescriptions for these drugs in the United States.
“Given the popularity of these drugs and the paucity of data on the magnitude of the risk of SRD (serous retinal detachment), RVO (retinal vascular occultation), and ION (ischemic optic neuropathy), we sought to undertake a large cohort study to quantify the risk for SRD, RVO, and ION associated with use of PDE5Is,” they wrote.
The study authors reported there were 1,146 cases that involved eye health issues. These included 278 cases of SRD, 628 cases of RVO, and 240 cases of ION. The mean age for all participants was almost 65 years.
“Patients with SRD, RVO, and ION were more likely to have hypertension, diabetes, coronary artery disease, and sleep apnea,” the authors noted.
“Findings of this cohort study suggest that regular users of PDE5Is might have an increased risk for SRD, RVO, and ION. Regular users of PDE5Is need to be cognizant of ocular adverse events associated with these drugs and alert their physicians if they experience any visual deficits,” the authors wrote.
The authors said the results of the study, which purports to be the largest of its kind, have been “conflicting.”
“The results of this cohort study confirm the findings from other studies regarding the risk of ION associated with PDE5I use but also quantifies the risk of SRD and RVO associated with use of these drugs, which has not been previously assessed,” the authors wrote.
Dr. Yuna Rapoport, a board-certified ophthalmologist with Manhattan Eye in New York, told Healthline that eye doctors were already aware of some connections between ED use and eye health.
“While it is known that ED drugs like Viagra and Cialis cause some ocular side effects, such as blue tint to everything visible, blurry vision, and light sensitivity, these are all relatively temporary and have to do with inhibitory action against PDE6, which is present exclusively in rod and cone photoreceptors in the retina,” Rapoport said.
“In regard to cyanopsia (blue tint to everything visible), patients typically have temporary red-green color blindness (those colors appear brown) and there is a blue tint to everything,” Rapoport added. “These are temporary. There is one condition- NAION – or non-arteritic ischemic optic neuropathy – that can occur that is permanent and can be triggered by ED meds. Those at risk for NAION (if you have a small cup to disc ratio in the optic nerve, or ‘disk at risk’) taking ED meds lowers the blood pressure by dilating blood vessels.”
“There have been a couple of individual case reports of retinal detachments in supplements for ED such as arginine, in patients who are already predisposed, but in general retinal detachment is not seen as a known side effect of ED meds,” Rapoport noted
A pharmacist who works with ED drugs told Healthline they should never be taken recreationally if the user doesn’t have erectile dysfunction.
“If erectile dysfunction medications are taken under supervision and carefully, after consulting with a practitioner, research found that it does not have permanent toxic effects on chorioretinal tissue and photoreceptors,” said Mat Rezaei, the CEO of Canadian digital pharmacy Upguys. “We do have to make sure that patients do not overdose. Negative side effects can occur when ED meds are taken recreationally.”
