Review of Testim® gel

Current topics in testosterone replacement of hypogonadal men

All forms of hypogonadism - primary, secondary and late-onset - require testosterone substitution. The indication is given when the patient presents with symptoms of androgen deficiency and the serum testosterone levels are below normal. Several testosterone preparations and modes of application are available of which those producing physiologic serum levels should be preferred e.g. preferentially transdermal gels and long-acting intramuscular testosterone undecanoate. Testosterone substitution must be monitored at regular intervals, best at 3, 6 and 12 months after initiation and then annually. Parameters for surveillance include well-being, libido and sexual activity, measurement of serum testosterone levels, haemoglobin and haematocrit, PSA and digital rectal examination, and, biannually, bone mineral density. Testosterone has positive effects on comorbidities such as obesity, metabolic syndrome, diabetes type II, cardiovascular diseases and osteoporosis.

Pharmacokinetics and bioavailability of a new testosterone gel formulation in comparison to Testogel® in healthy men

This randomized, open-label, multiple-dose three-way cross-over study compared the pharmacokinetics of a new testosterone gel formulation in two strengths, testosterone gel 1% and testosterone gel 2% (FE 999303), with Testogel® in 11 testosterone-suppressed healthy men. Subjects received one of six treatment sequences; 50 mg of testosterone was administered once daily for 7 consecutive days, with different treatments separated by washout-periods of 6-9 days. Testosterone gel 1% and testosterone gel 2% displayed greater relative bioavailability (2.6- and 1.6-fold, respectively) than Testogel on Day 1, which persisted, to a smaller extent, on Day 7. Initial absorption was highest and most rapid for testosterone gel 1% and 2%, showing apparent first-order absorption kinetics. Maximum serum concentrations (Cmax ) were 6.25 and 2.97 ng/mL, respectively, occurring ∼5-6 hours post-application on Day 1 versus Cmax of 1.71 ng/mL after ∼24 hours with Testogel, showing apparent zero-order absorption kinetics. Similar differences were observed on Day 7. All treatments appeared to reach approximately the same steady-state level within the first 24 hours. No application-site skin reactions occurred with any preparation. In conclusion, the new testosterone formulation showed higher bioavailability, and the ability to deliver more testosterone in a smaller volume.

Transdermal testosterone replacement therapy in men

Androgen deficiency syndrome in men is a frequently diagnosed condition associated with clinical symptoms including fatigue, decreased libido, erectile dysfunction, and metabolic syndrome. Serum testosterone concentrations decline steadily with age. The prevalence of androgen deficiency syndrome in men varies depending on the age group, known and unknown comorbidities, and the respective study group. Reported prevalence rates may be underestimated, as not every man with symptoms of androgen deficiency seeks treatment. Additionally, men reporting symptoms of androgen deficiency may not be correctly diagnosed due to the vagueness of the symptom quality. The treatment of androgen deficiency syndrome or male hypogonadism may sometimes be difficult due to various reasons. There is no consensus as to when to start treating a respective man or with regards to the best treatment option for an individual patient. There is also lack of familiarity with treatment options among general practitioners. The formulations currently available on the market are generally expensive and dose adjustment protocols for each differ. All these factors add to the complexity of testosterone replacement therapy. In this article we will discuss the general indications of transdermal testosterone replacement therapy, available formulations, dosage, application sites, and recommended titration schedule.

Optimal diagnostic measures and thresholds for hypogonadism in men with HIV/AIDS: comparison between 2 transdermal testosterone replacement therapy gels

OBJECTIVES

To determine the incidence of hypogonadism in men with human immunodeficiency virus (HIV)/acquired immunodeficiency virus (AIDS), the most useful serum testosterone measurement and threshold for diagnosing hypogonadism, and the comparative efficacy of 2 testosterone replacement therapy (TRT) 1% gels (AndroGel® [Abbott Laboratories] and Testim® [Auxilium Pharmaceuticals, Inc.]).

DESIGN AND SUBJECTS

This was a 2-stage observational study. In stage 1, patient records from 2 medical practices specializing in HIV/AIDS were reviewed. Eligible patients were aged ≥ 18 years; had HIV-seropositive status confirmed by enzyme-linked immunosorbent assay and western blot test or HIV-1 viremia confirmed by HIV-1 RNA polymerase chain reaction; and had prior baseline testosterone assessments for hypogonadism (ie, presence of signs/symptoms of hypogonadism as well as total testosterone [TT] and free testosterone [FT] level measurements). Stage 2 included the evaluation of patients from stage 1 who were treated with 5 to 10 g/day of TRT. The stage 2 inclusion criteria were a diagnosis of low testosterone (defined as TT level < 300 ng/dL and/or FT level < 50 pg/mL, as per The Endocrine Society guidelines and presence/absence of hypogonadal signs and symptoms); ≥ 12 months of evaluable sign and symptom assessments and TT/FT level measurements while on TRT with either Testim® or AndroGel®; and ≥ 4 weeks on initial TRT if the initial TRT was switched or discontinued.

RESULTS

Four hundred one of 422 patients met the stage 1 inclusion criteria and 167 of 401 patients (AndroGel®, n = 92; Testim®, n = 75) met the stage 2 inclusion criteria. Total testosterone level < 300 ng/dL alone identified 24% (94 of 390) of patients as hypogonadal, but failed to diagnose an additional 111 patients (67.7%) with FT levels < 100 pg/mL and hypogonadal symptoms. Through month 12, AndroGel® increased mean TT levels by +42.8% and FT levels by +66.9%, compared with +178.7% (P = 0.017) and +191% (P = 0.039), respectively, for Testim®. Patients treated with Testim® showed significantly greater improvements in libido, sexual performance, nighttime energy, focus/concentration, and abdominal girth, and trends for greater improvement in fatigue and erectile dysfunction than patients treated with AndroGel®. No patients discontinued therapy due to adverse events.

CONCLUSION

The most useful serum testosterone measurement and threshold for diagnosing hypogonadism in men with HIV/AIDS was FT level < 100 pg/mL, which identified 64% of men as hypogonadal with the presence of ≥ 1 hypogonadal symptom. This is above currently accepted thresholds. Criteria using TT level < 300 ng/dL and FT level < 50 pg/mL only diagnosed 24% and 19% of patients, respectively, as having hypogonadism. Testim® was more effective than AndroGel® in increasing TT and FT levels and improving hypogonadal symptoms.

Topical testosterone supplementation for the treatment of male hypogonadism

Age-related hormonal decline is gradual and less recognized in men than in women. Symptoms are oftentimes ignored and non-specific. Fatigue, lack of concentration, mood swings, decreased sexual desire, erectile dysfunction, infertility, hair loss, reduced muscle and bone mass, and weight gain are a few of the symptoms of male hypogonadism. This disorder is linked to reduction in quality of life, and poorer health outcomes as it may increase the risk for cardiovascular disease, diabetes mellitus, metabolic syndrome, Alzheimer's disease and premature death. Different modalities of testosterone replacement therapy have evolved over 70 years, and sales continue to grow. Each preparation is differentiated by route of delivery, ease of use, cost and pharmacokinetics. Topical/transdermal testosterone replacement therapy, including patches and gels, are the most modern formulations on the market. These are more expensive treatments, but yield more physiological concentrations of testosterone. Restoration of testosterone levels to the eugonadal range reverses signs and symptoms of hypogonadism, except for infertility, and may alleviate co-morbidities associated with hypogonadism. Patient understanding of and compliance with both treatment and monitoring are of utmost importance to achieve clinical success with maximum benefit and minimum risk. The aim of our review is to summarize the indications, contraindications, benefits and risks of testosterone replacement therapy as they relate to transdermal administration. Further, we compare the various testosterone preparations, focusing on the newest topical/transdermal routes of administration that are currently available.

How to help the aging male? Current approaches to hypogonadism in primary care

Hypogonadism is a common condition which occurs more frequently in older men. It is characterized by low testosterone (T) and is associated with symptoms which are often nonspecific. A key symptom is low libido, but it can also be associated with erectile dysfunction, reduced muscle mass and strength, increased body fat, reduced bone mineral density and osteoporosis, reduced vitality, and depressed mood. Hypogonadism is linked with a variety of comorbid conditions including erectile dysfunction, metabolic syndrome, diabetes, obesity, and osteoporosis. However, the condition is often underdiagnosed. T supplementation in hypogonadism is associated with a range of benefits including improved sexual function, increased lean body mass and/or reduced fat mass, and improved bone mineral density. A variety of T supplementation formulations are available. Although there is no evidence of increased risk of initiating prostate cancer with T supplementation, it is contraindicated in men with prostate cancer. It is important that primary care physicians are aware of both the signs and symptoms of hypogonadism, the monitoring and testing that is required and the merits and advantages of the various T preparations to ensure optimal management of the condition with a treatment approach that best suits patients' needs.

Men's health, low testosterone, and diabetes: individualized treatment and a multidisciplinary approach

Testosterone plays a critical role in male reproductive and metabolic functioning. Serum testosterone levels decrease with age, and low testosterone is associated with a variety of comorbidities, including insulin resistance, type 2 diabetes, obesity, metabolic syndrome, and cardiovascular disease. Men with type 2 diabetes have been shown to have significantly lower testosterone levels than men without diabetes. Several forms of testosterone replacement therapy (eg, oral, injectable, buccal, transdermal preparations) are available for use in the United States. The primary goals of testosterone therapy are to restore physiologic testosterone levels and reduce the symptoms of hypogonadism. Testosterone therapy may be a viable option in some men with diabetes and low testosterone; however, clinicians must be aware of contraindications to therapy (eg, prostate cancer and male breast cancer), implement appropriate monitoring procedures, and ensure that patient expectations are realistic regarding treatment outcome. Data suggest that testosterone therapy may have a positive effect on bones, muscles, erythropoiesis and anemia, libido, mood and cognition, penile erection, cholesterol, fasting blood glucose, glycated hemoglobin, insulin resistance, visceral adiposity, and quality of life. Sexual health may be a window into men's health; thus, more effective communication strategies are needed between clinicians and men with diabetes to ensure that sexual health topics are adequately addressed. Diabetes educators can play a key role in screening for low testosterone, providing relevant information to patients, and increasing clinician awareness of the need to address men's sexual health and implement appropriate strategies. Multidisciplinary care and individualized treatment are needed to optimize outcome.