Viagra and Levitra are commonly used erectile dysfunction drugs that offer an answer to some men suffering from this condition. Well, researchers at Cedars-Sinai Medical Center looked more closely at these drugs because of the nature of their actions. They are both PDE5 inhibitors because they block an enzyme, phosphodiesterase5 which would normally cause decreased blood flow to the penis and surrounding area and obviously result in ED. So blocking the enzyme means increased blood flow.
In the brain, there is an established "blood-brain barrier" whose role is to prevent anything alien so to speak, from entering the brain and harming it. But in the case of certain brain tumors we need drugs to pass this barrier - and often times they hit this natural road block. Apparently these 2 erectile dysfunction drugs enhance the drug transport of these therapeutic tumor drugs into the brain.
Adriamycin, a commonly used chemotherapy agent had its specific transport enhanced and it more easily crossed the blood-brain barrier when the patient was given an oral dose of a PDE5 drug and then the chemotherapy. Previously a peptide called bradykinin was used to help transport drugs into the brain successfully, but Levitra and Viagra apparently have a longer lasting and sustained impact - obviously a great finding!!
Survival rates of the rats with the brain tumors given adriamycin plus a PDE5 drug (specifically Levitra which out-performed Viagra) exceeded the other rats treated just with adriamycin. How great that a drug used for ED has this other incredible therapeutic impact.
Published On: July 28, 2008