Androgen Replacement Therapy: Treatment Advances and Clinical Implications

Discussion in 'Articles' started by PillarofBalance, Apr 12, 2012.

  1. PillarofBalance

    PillarofBalance Strength Pimp Staff Member

    Feb 27, 2011
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    Randall B Meacham, MD
    Division of Urology, University of Colorado School of Medicine, Denver, CO
    Dr Meacham serves on the Speakers’ Bureau and Advisory Boards of Solvay Pharmaceuticals and Auxilium Pharmaceuticals.

    Over the past several years, a great deal of attention has been focused on the progressive decline of circulating testosterone levels as a function of male aging. A recently published longitudinal study demonstrated the incidence of hypogonadism to be 12% among men in their fifties, 19% among men in their sixties, 28% among men in their seventies, and 49% among men in their eighties.1 This decline in testosterone has been linked to a series of symptoms collectively referred to as androgen deficiency in the aging male (ADAM). Symptoms include decreased muscle mass and strength, decreased ratio of lean body mass to adipose tissue, osteoporosis, decreased sexual function, decreased hematocrit, impaired cognition, and mood disorders. It has been demonstrated that many of these conditions can be partially alleviated through androgen replacement therapy.2
    These findings have generated interest in identifying improved methods of administering supplemental testosterone. The longest established method, intramuscular injection of depot testosterone, requires repeated deep-muscular injections and is associated with nonphysiologic swings in serum testosterone levels. Following injection, serum testosterone levels spike sharply and then progressively decline, often falling below the normal range before the next injection is given. The advent of transdermal testosterone patches constituted an improvement, providing a less invasive method of delivery with less variation in serum androgen levels between doses. Subsequent development of a transdermal gel further expanded and improved the options for androgen replacement, reducing skin irritation and obviating the need to wear a patch. Recently, an additional testosterone gel formulation, which appears to have unique characteristics, has been approved by the US Food and Drug Administration.

    A Novel Testosterone Gel Formulation Normalizes Androgen Levels in Hypogonadal Men, With Improvements in Body Composition and Sexual Function
    McNicholas TA, Dean H, Mulder C, et al.
    BJU Int. 2003;91:69–74. [PubMed].
    This report compares the administration of a newly developed androgen-replacement gel (Testim™, Auxilium Pharmaceuticals, Norristown, Pa), at 2 dosing strengths, with a permeation-enhanced testosterone patch (Andropatch®, GlaxoSmithKline, Middlesex, UK) in a group of 208 hypogonadal men. The gel was administered once daily at doses of 50 mg or 100 mg, delivering 5 mg or 10 mg of testosterone, respectively. The patch was administered as two 2.5-mg patches per day, each containing 12.2 mg of testosterone. All 3 treatments were administered for 90 days.
    The gel produced dose-dependent increases in serum testosterone that were significantly greater than with the patch. The 100-mg gel dose generated an increase in serum testosterone twice that seen with the 50-mg dose and 3 times that seen with the patch. The gel was better tolerated than the patch: 13% of patients who received the patch withdrew from the study because of skin reactions at the application site, compared with study withdrawal rates of 4% and 0% in the patients who received 50-mg and 100-mg doses of the gel, respectively.
    During the course of treatment, patients in all 3 groups exhibited improved sexual motivation, desire, and performance. Subjects who received either dose of the gel experienced a statistically significant increase in spontaneous erections during the study period, whereas those who received the patch did not. Patients in all treatment groups experienced an increase in lean body mass; those in the 100-mg gel group also experienced a decrease in percent body fat. Subjects who received the gel were noted to have an improvement in overall mood, whereas those who received the patch did not.
    The authors noted that treatment with this novel gel formulation generated significantly greater changes in serum testosterone than did treatment administered via patch. In this study, testosterone replacement was associated with improved sexual function, mood, and lean body mass. Furthermore, a more favorable response was noted among subjects who received the gel formulation versus the patch in regard to mood, reduction in body fat, and spontaneous erections. It may be that the increase in testosterone levels achieved with this new gel accounts for the improved response seen in patients in whom testosterone is administered in this manner.
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    Prostate-Specific Antigen Changes in Hypogonadal Men Treated With Testosterone Replacement
    Gerstenbluth RE, Maniam PN, Corty EW, Seftel AD
    J Androl. 2002;23:922–926. [PubMed].
    One concern that has been expressed regarding androgen replacement therapy is its potential impact on the development or acceleration of prostate cancer. Such concern is based on the principles that prostate cancer is typically an androgen-dependent malignancy and that patients who are candidates for androgen replacement are often in an age group for which occult prostate cancer is relatively common. Moreover, a report by Morgentaler and colleagues3 indicates that occult prostate cancer may be more prevalent among hypogonadal men than in the general population.
    In an effort to shed additional light on this subject, Gerstenbluth and colleagues reviewed the effect of androgen replacement therapy on the serum prostate-specific antigen (PSA) levels of 54 hypogonadal men and their corresponding development of prostate cancer. All subjects received intramuscular injections of testosterone. Dosing schedules varied based on clinical response. At 30.2 months, mean follow-up was longer than in many studies addressing this issue. Mean testosterone levels increased from 189 ng/dL pretreatment to 974 ng/dL during therapy. Mean serum PSA values increased from 1.86 ng/mL to 2.82 ng/mL (mean PSA change, 0.96 ng/mL). Six patients underwent prostate biopsy based on elevation of serum PSA. One of these patients was found to have prostate cancer. This patient’s pretreatment PSA level was 3.70 ng/mL and, after 15 months of treatment, rose to 5.90 ng/mL.
    The authors concluded that androgen replacement therapy in this group of hypogonadal men resulted in a relatively limited increase in serum PSA level and that there did not appear to be a significant increase in the short-term risk of prostate cancer.
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    Summary
    It has been estimated that roughly 5 million men in the United States are hypogonadal. As our population ages, this number will certainly increase. This demographic trend is accompanied by an understandable interest in the preservation of vitality and physical function well into old age, and a number of reports have indicated that androgen replacement offers real benefit to hypogonadal men.
    As the baby boom generation reaches their sixties and seventies, the demand for solutions to the various ailments associated with aging will undoubtedly take on additional stridence. One demand will be the provision for more convenient and effective methods of achieving androgen replacement. Of equal importance, however, is the need to identify those individuals who will benefit most from replacement therapy and to assess the possible detrimental effects of such therapy. A normal androgen milieu is important for prostatic growth and the production of PSA. It stands to reason, therefore, that hypogonadal men might present with decreased serum PSA levels and that androgen replacement would increase PSA values in comparison to those seen in eugonadal men. Whether such replacement therapy might increase the risk of detectable prostate cancer remains a topic of discussion. The report reviewed here, however, suggests that, in the short term, this does not appear to be the case.
    References
    1. Harman SM, Metter EJ, Tobin JD, et al. Longitudinal effects of aging on serum total and free testosterone levels in healthy men. J Clin Endocrinol Metab. 2001;86:724–731. [PubMed]
    2. Tenover JL. Testosterone replacement therapy in older adult men. Int J Androl. 1999;22:300–306. [PubMed]
    3. Morgentaler A, Bruning CO, 3rd, DeWolf WC. Occult prostate cancer in men with low serum testosterone levels. JAMA. 1996;276:1904–1906. [PubMed]
     
  2. DaSarge

    DaSarge VIP Member

    Nov 20, 2014
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    Great read. Thanks for posting.
     

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