Sildenafil, commonly known to us as Viagra, is a very famous drug for the treatment of Impotence. In 2005, Dr Howard Pomeranz, director Neuro-ophthalmology from the University of Minnesota Medical School published a paper that confirmed the existence of the link between the blindness that occurs in users of Viagra, and the drug itself. The main cause of this blindness is a phenomenon known as non-arteritic ischemic optic neuropathy (NAION). It usually affects one eye, & can be temporary or permanent. A similar side effect is also seen with another drug Cialis, used for the treatment of ED (Erectile Dysfunction) but to a much lesser extent. According to Health Canada, the users of the three erectile dysfunction drugs Viagra (sildenafil), Cialis (tadalafil) and Levitra (vardenafil) are advised to seek immediate medical assistance if they suffer sudden vision loss or other vision-related problems on taking these medications.
In 2005, an alert was issued by the FDA of United States of America, according to which there were a few cases reporting of loss of vision in one eye after taking drugs like Levitra, Viagra, or Cialis. This vision loss is known as non-arteritic anterior ischemic optic neuropathy (NAION). NAION results in a sudden loss of eyesight because flow of blood is impaired to the optic nerve. NAION also affects men who do not use these drugs.
The FDA of United States of America also discovered that most of the patients who suffered from loss of eyesight had diabetes and cardiovascular problems too. According to the Australian official patient information regarding Viagra (the Consumer Medical Information or CMI) its not definite still if the cause of NAION is Viagra or similar drugs used for the treatment of ED- Erectile Dysfunction. Loss of eyesight in one or both eyes should be dealt as a medical emergency."
Warnings stated in the Cialis and Levitra CMIs are somewhat similar. Recently a report stated that these drugs may also cause hearing loss.
This side effect has been observed with almost all of the PDE5 inhibitors Viagra, Levitra, Cialis, which are being used today for the treatment of erectile dysfunction, also known as impotence commonly. Tinnitus and dizziness have also been reported to coexist in some cases along with hearing loss. However, it’s hard to comment whether are these problems side effects of these drugs, or because of drug-drug interactions between other drugs being used at the same time and these PDE5 inhibitors, or are these medical ailments due to some other reason. The US drug information was changed in November 2007 and this side effect of hearing loss also included. However, this has still not been mentioned in any of the Australian CMIs as a side effect of drugs being used to treat impotence.
Other side effects of these drugs are headache and abdominal discomfort, but they are so slight that they are usually beared by the patient. However, exceptional cases can exist. Viagra is manufactured by Pfizer Pharmaceuticals, New York and is a diamond shaped tablet, available for 12 dollars in the United States.
