Viagra, anti-cancer drug combo shrinks tumours: Study

Viagra when combined with doxorubicin, a powerful anti-cancer drug, enhances its anti-tumour efficacy in prostate cancer, and also lessens the damage to the heart, suggests a new study.

For more than four decades, the chemotherapeutic agent doxorubicin has been used to treat a number of human cancers, including that of the prostate.

Virginia Commonwealth University School of Medicine and VCU Massey Cancer Centre researchers, using a variety of powerful in-vitro and in-vivo approaches, have shown that a combination of Viagra, generically known as sildenafil, and doxorubcin significantly enhances the generation of reactive oxygen species that trigger cell death, or apoptosis, in prostate cancer cells.

They also observed that the combination did not harm the normal, healthy prostate epithelial cells.

"We believed that sildenafil could be an excellent candidate for incorporation into cancer treatment protocols — with the potential of enhancing the anti-tumour efficacy while protecting the heart against both short-term and long-term damage from doxorubicin," said Rakesh C Kukreja, principal investigator of the study.

Kukreja's laboratory is one of the first to explore the area of pre-conditioning. This pre-conditioning effect was modelled in his lab by 'pre-treating' mice with doses of sildenafil, which also increased therapeutic levels of nitric oxide in the heart.

The study was published online in the journal Proceedings of the National Academy of Sciences.