FDA Updates Labeling for Viagra, Cialis and Levitra for Rare Post-Marketing Reports of Eye Problems

The Food and Drug Administration today approved updated labeling for Cialis, Levitra and Viagra to reflect a small number of post-marketing reports of sudden vision loss, attributed to NAION (non arteritic ischemic optic neuropathy), a condition where blood flow is blocked to the optic nerve.

FDA advises patients to stop taking these medicines, and call a doctor or healthcare provider right away if they experience sudden or decreased vision loss in one or both eyes. Further, patients taking or considering taking these products should inform their health care professionals if they have ever had severe loss of vision, which might reflect a prior episode of NAION. Such patients are at an increased risk of developing NAION again.

At this time, it is not possible to determine whether these oral medicines for erectile dysfunction were the cause of the loss of eyesight or whether the problem is related to other factors such as high blood pressure or diabetes, or to a combination of these problems. The new labeling information is available along with additional information for healthcare providers and consumers online at:

Viagra ( http://www.fda.gov/cder/consumerinfo/viagra/vIAGRA.htm)

Levitra http://www.fda.gov/cder/drug/infopage/vardenafil/default.htm

Cialis http://www.fda.gov/cder/drug/infopage/cialis/default.htm

Tissue Engineering for Erectile Dysfunction

New Graft Material Facilitates Nerve Repair 
 
CHICAGO - Researchers at Children's Hospital Boston report an important advance in tissue engineering of the penis, raising hopes that men with severe impotence - due to penile trauma, surgery, cancer, congenital malformations or other conditions - may someday be able to regain sexual function.
These findings, presented at the American Urological Association meeting in Chicago, have implications for men who need reconstruction of the penis, and for men whose penis is intact but has suffered nerve damage - such as men who have undergone radical surgery for prostate cancer.

Although the body of the penis can be grown in the lab through tissue engineering using smooth muscle cells, the organ needs a working network of nerves in order to achieve erection and function sexually. This animal study, led by Anthony Atala, MD, a pediatric urologist and director of Tissue Engineering at Children's Hospital Boston, showed that implantation of engineered tissue made of collagen can coax nerves to regenerate in the penis.

The investigators cut the cavernosal nerves - the two bundles of nerves innervating the penis - in 90 rats. At the injury site, they implanted either a graft of the rats' own nerves, or a graft made from collagen, a natural protein found in connective tissue. Some severed nerves were left untreated. The collagen grafts had been engineered to form a channel shape, similar to the natural sheath of a nerve, and follow-up studies three months later showed that the rats' own nerve cells had regenerated and infiltrated this 'scaffolding' material. 'We used the body's own healing abilities to create the tissue,' explains Atala.
 
The degree of nerve regeneration with the collagen grafts equaled that of both normal, undamaged nerves, and the grafts consisting of the rats' own nerves. The severed nerves that were left untreated showed no signs of regeneration.
Atala's lab previously showed that the tissue making up the body of the penis can be successfully grown in the lab, and successfully used to reconstruct the penises of rabbits that had part of the organ surgically removed. This new study takes penile reconstruction a step further; showing that the nerves required for erectile function can be induced to grow through tissue engineering.