This group did not show the risks demonstrated in the combination hormone study, and the estrogen-only study was not halted in 2002. However, in February 2004 it, too, was halted. While there was a 23% decreased incidence of breast cancer in the estrogen-only study participants, risks of stroke and pulmonary embolism were increased slightly, predominantly in patients who began HRT over the age of 60.Several other large studies and meta-analyses have reported reduced mortality for HRT in women younger than age 60 or within 10 years of menopause, and a debatable or absent effect on mortality in women over 60.Though research thus far has been substantial, further investigation is needed to fully understand differences in effect for different types of HRT and lengths of time since menopause. Available forms
There are five major human steroid hormones: estrogens, progestogens, androgens, mineralocorticoids, and glucocorticoids. Estrogens and progestogens are the two most often used in menopause. They are available in a wide variety of FDA approved and non–FDA-approved formulations.In women with intact uteruses, estrogens are almost always given in combination with progestogens, as long-term unopposed estrogen therapy is associated with a markedly increased risk of endometrial hyperplasia and endometrial cancer. Conversely, in women who have undergone a hysterectomy or do not have a uterus, a progestogen is not required, and estrogen can be used alone. There are many combined formulations which include both estrogen and progestogen.
The substance is the same under both trade names.In 1992, Pfizer filed a patent covering the substance sildenafil and its use to treat cardiovascular diseases. This would be marketed as Revatio. The patent was published in 1993 and expired in 2012. The patent on Revatio (indicated for pulmonary arterial hypertension rather than erectile dysfunction) expired in late 2012. Generic versions of this low-dose form of sildenafil have been available in the U.S. from a number of manufacturers, including Greenstone, Mylan, and Watson, since early 2013. Health care providers may prescribe generic sildenafil for erectile dysfunction. However, the generic is not available in the same dosages as branded Viagra, so using dosages typically required for treating ED requires patients to take multiple pills.In 1994, Pfizer filed a patent covering the use of sildenafil to treat erectile dysfunction. This would be marketed as Viagra. This patent was published in 2002 and will expire in 2019. Teva sued to have the latter patent invalidated, but Pfizer prevailed in an August 2011 federal district court case. An agreement with Pfizer allowed Teva to begin to provide the generic drug in December 2017. References
External links

"Sildenafil". Drug Information Portal. U.S. National Library of Medicine. "Sildenafil citrate". Drug Information Portal. U.S. National Library of Medicine. Viagra at The Periodic Table of Videos (University of Nottingham)