Viagra affects males and females differently in heart failure treatment

A new study has revealed that sildenafil, the erectile dysfunction drug sold as Viagra and now under consideration as a treatment for heart failure, affects males and females very differently.

According to the cardiovascular researchers of Johns Hopkins University, in female mice modeling human heart failure, the benefits of sildenafil ranged from robust to practically nonexistent, depending on the animals' levels of the hormone estrogen.

Lead scientist Eiki Takimoto said that sildenafil generally appears to work well, but only because it targets a different biological process independent of estrogen in males.

He said that the research is especially significant because it offers a mechanism to explain how estrogen affects sildenafil's efficacy and its the first time the actual pathway of a hormone's cause and effect on a drug has been mapped out.

The study was published in The Journal of Clinical Investigation.