FDA Approves Gel to Treat Low Testosterone Levels
"In none of the partners of the individuals who were treated with testosterone were there any significant clinical problems," Swerdloff tells WebMD. "Because there is a potential for testosterone transfer, the recommendation is that patients shower before intimate contact or wear a shirt over the area to which the drug is applied. The testosterone is driven into the skin, so showering doesn't alter the effectiveness of the testosterone."
To assess the effectiveness of AndroGel, researchers studied 227 men with low testosterone levels. The men received either AndroGel in varying doses, or testosterone through a skin-patch delivery system. After 60 days, their blood levels of testosterone were checked and the doses were adjusted. Of the 129 men who were appropriately adjusted, 87% achieved normal levels of testosterone that were maintained for the remaining three months of the trial. In this and other trials, side effects were moderate but infrequent -- mostly skin reactions to the gel, including acne; prostate and urinary problems; and swelling.
"We were able to put the testosterone into the normal blood range in the majority of the people. It's simply a matter of adjusting the amount of gel that's applied. So everybody could be treated once a proper dosage [is] determined," Swerdloff says. The manufacturer recommends checking the blood two weeks after starting.
"The positive effects were on sexual drive and on mood," Swerdloff says. "People had less depressive symptoms. There was an improvement in the lean body mass and muscle strength. ... It was surprising to us that within six months of treatment, there was a significant increase of bone mineral density."
Swerdloff tells WebMD that there are many potential applications for testosterone. It is being studied in combination with other hormones as a male contraceptive. Many researchers are looking at giving androgen replacement therapy in men over 65. Testosterone may also one day be used in women to improve libido, or added to conventional hormonal therapy to help improve bone mineral density. AndroGel is only approved for men and has not been studied in those over age 65.