Sildenafil
Originally intended to treat pulmonary hypertension, angina, and other cardiovascular diseases, sildenafil citrate was unintentionally discovered to be useful in males suffering from erectile dysfunction (ED). Prior to the discovery of its therapeutic effects in the treatment of ED, this condition was thought to be an unavoidable component of aging in men or the result of underlying psychological problems. After being approved by the U.S. Food and Drug Administration in 1998 for the treatment of ED, sildenafil citrate’s popularity has skyrocketed over the last few decades, with health care providers generally recommending this medication as first-line therapy in the management of erectile dysfunction in men. Other aspects that contribute to its attraction and popularity include the fact that sildenafil citrate can be taken orally on demand and is generally well tolerated with little side effects. 1

Sildenafil citrate is a vasoactive medicine that belongs to the pharmacologic class of PDE-5 inhibitors; it is a competitive antagonist of this enzyme. PDE-5 is distributed throughout the human body, particularly in the corpus cavernosum within the penis, striated and smooth muscle, and platelets. However, PDE-5 is more prevalent in the penile corpus cavernosum, which explains why sildenafil citrate can function selectively in this area of the body. 2

Sildenafil citrate is often used orally. It can, however, be given intravenously or sublingually. Although its most common therapeutic application is for the treatment of erectile dysfunction, it is also used to treat pulmonary hypertension, infant pulmonary hypertension, Raynaud’s phenomenon refractory to other vasodilators, and to prevent pulmonary edema at high altitudes. Following oral administration, sildenafil citrate is rapidly absorbed, primarily in the small intestine, and is then carried through the bloodstream to its site of action. The hepatic isoenzymes cytochrome P450 3A4 and cytochrome P450 2C9 metabolize sildenafil citrate in the liver. Following hepatic metabolism, metabolites are primarily eliminated in the stool and, to a lesser extent, in the urine. 234

The Food and Medication Administration classifies sildenafil citrate as a pregnancy category B drug. Studies have found no definitive dangers to fetuses when sildenafil is given to pregnant women. There are currently no proven clinical indications for the use of sildenafil citrate in women. To yet, no studies have shown that sildenafil citrate has the same benefits in women as it does in men. Other trials, however, are still continuing, and the results may provide additional insight into the usability and benefits of sildenafil in women.

Testosterone
The predominant androgen present in the body is testosterone. Cells in the testis, ovary, and adrenal cortex produce endogenous testosterone. In the treatment of hypogonadism, either congenital or acquired, testosterone is employed. Testosterone is also the most effective exogenous androgen for the palliative treatment of postmenopausal women with breast cancer. Testosterone was first used in 1938, and the FDA approved it in 1939. Anabolic steroids, which are testosterone derivatives, have been used illegally and are now restricted substances. In 1991, testosterone, like many anabolic steroids, was designated as a restricted substance. Uniumed Pharmaceuticals developed testosterone cream as AndroGel in the United States, and it was FDA approved in 2000 for the treatment of testosterone deficiency, which often results in a variety of hypogonadic conditions ranging from mood and energy to sexual dysfunctions, as well as a treatment for several injury-related conditions such as those experienced by severe burn and accident victims. AndroGel is a very popular form of testosterone that is sold around the world under a few less well-known brand/trade names, most notably Testogel (manufactured in the UK by Laboratoires Besins and distributed by Bayer), Testim (manufactured in the US by Auxilium Pharmaceuticals, Inc.), and various generic versions often sold under the name testosterone cream or gel.

The transdermal testosterone cream delivery technique targets the same, or very comparable, body locations as injections and other kinds of testosterone. More specifically, maximum absorption of testosterone cream is attained when it is applied to heavily muscled bodily regions (as with injectable testosterone). Because more muscle at the area of application correlates to a greater number of testosterone-absorbing capillaries, testosterone may be shuttled into the bloodstream more quickly. 5