Pharmacokinetics of testosterone therapies in relation to diurnal variation of serum testosterone levels as men age

Safety, efficacy, and pharmacokinetics of oral testosterone undecanoate in males with hypogonadism

BACKGROUND

Testosterone deficiency results from insufficient testosterone production. Testosterone therapy may require dose titration to reach eugonadal serum testosterone concentrations.

OBJECTIVE

The primary objective was the efficacy of oral testosterone undecanoate (TLANDO; Antares Pharma Inc.) in male patients with documented hypogonadism. Secondary objectives included a comparison of oral testosterone undecanoate safety and quality-of-life assessments to 1.62% topical testosterone gel (AndroGel 1.62%; AbbVie).

MATERIALS AND METHODS

In this phase 3 study, 315 patients were randomized 2:1 to oral testosterone undecanoate or 1.62% topical testosterone gel (NCT02081300). Patients received 225 mg oral testosterone undecanoate twice daily, and doses were adjusted by 75 mg/dose at weeks 4 and 8 based on average serum total testosterone concentration and maximum observed serum concentration. The primary endpoint was the proportion of patients receiving oral testosterone undecanoate with serum total testosterone concentration within the eugonadal reference range (300-1140 ng/dL). Secondary endpoints included the proportion of patients with maximum serum total testosterone concentrations within predetermined limits, safety parameters, and quality-of-life endpoints including the Short Form-36v2 Health Survey, Psychosexual Daily Questionnaire, and International Prostate Symptom Score.

RESULTS

Overall mean ± SD baseline testosterone was 205.7 ± 71.6 ng/dL. For patients receiving oral testosterone undecanoate, 87.4% demonstrated a 24-h average serum total testosterone concentration within the reference range following titration. Oral testosterone undecanoate demonstrated a nominal statistically significantly greater mean change from baseline than 1.62% topical testosterone gel for Short Form-36v2 Health Survey measures of mental health (2.91 vs. -0.10; p = 0.035), and mental component summary (3.82 vs. 0.55; p = 0.009); and Psychosexual Daily Questionnaire measure of weekly negative mood (-0.57 vs. -0.20; p = 0.021). Safety endpoints were comparable between therapies. No deaths or treatment-related serious adverse events were reported.

DISCUSSION AND CONCLUSION

Male patients with hypogonadism receiving oral testosterone undecanoate 225 mg twice daily demonstrated improvements in libido and sexual frequency. Serum testosterone concentrations were within the reference range in 87% of patients without dose titration.

Regulation of testosterone synthesis by circadian clock genes and its research progress in male diseases

ABSTRACT

The circadian clock is an important internal time regulatory system for a range of physiological and behavioral rhythms within living organisms. Testosterone, as one of the most critical sex hormones, is essential for the development of the reproductive system, maintenance of reproductive function, and the overall health of males. The secretion of testosterone in mammals is characterized by distinct circadian rhythms and is closely associated with the regulation of circadian clock genes. Here we review the central and peripheral regulatory mechanisms underlying the influence of circadian clock genes upon testosterone synthesis. We also examined the specific effects of these genes on the occurrence, development, and treatment of common male diseases, including late-onset hypogonadism, erectile dysfunction, male infertility, and prostate cancer.

Late-onset hypogonadism: current methods of clinical diagnosis and treatment in Japan

ABSTRACT

Testosterone affects several organs in the body and is very important for male well-being. Aging men with late-onset hypogonadism (LOH) experience physiologic, psychiatric, and sexual symptoms related to a decline in the serum concentration of testosterone with age. However, it is well-known that the extent of the decline in testosterone concentration does not correlate with the severity of LOH-related symptoms. Therefore, it is difficult to diagnose and treat patients with LOH. In addition, the symptoms, response to testosterone replacement therapy (TRT), and medical insurance coverage differ among ethnicities and countries. The evaluation of testosterone is essential for the diagnosis and treatment of LOH. The effects of testosterone are determined not only by the serum testosterone concentration but also by the androgen receptor sensitivity. A low number of glutamine repeats is indicative of high androgenic activity, and the number shows ethnicity-related differences (fewer in African American than in Caucasian people and more in East Asian people). The diagnosis of LOH is typically made using subjective symptoms and the serum testosterone concentration. The Aging Male Symptoms scale is widely used to evaluate the symptoms. The normal range of total testosterone concentration varies around the world; therefore, clinicians should follow the guidelines of their regional academic society. The principal treatment for LOH is TRT. There are many types of TRT and other treatment strategies are also available. Thus, physicians should treat LOH according to each patient's situation, considering related disorders, such as diabetes, osteoporosis, metabolic syndrome, and depression.

Age-related impairment in testosterone elevation after anterior fibromuscular stroma preserved enucleation

OBJECTIVES

This study aims to evaluate the impact of anterior fibromuscular stroma preserved enucleation (AFSPE) of the prostate on serum testosterone levels in patients with benign prostatic obstruction (BPO) and to explore age-related differences in postoperative testosterone elevation.

METHODS

In a retrospective analysis, 304 patients from a pool of 560 who underwent AFSPE at Linkou Chang Gung Memorial Hospital between January 2018 and December 2021 were evaluated. Patients were stratified based on preoperative testosterone levels into low (<3.5 ng/mL) and normal (≥3.5 ng/mL) groups. Serum testosterone levels were measured preoperatively, at 1.5 and 3-6 months postoperatively. Age and other demographic data were analyzed as potential factors influencing testosterone changes.

RESULTS

The low-testosterone group (n = 90) showed significant testosterone increases, from an average of 2.61 ng/mL preoperatively to 3.3 ng/mL at 1.5 months and 3.59 ng/mL at 3-6 months postoperatively (p < 0.0001). The normal-testosterone group (n = 214) maintained stable testosterone levels at 1.5 months but exhibited a significant rise to 6.06 ng/mL by 3-6 months (p = 0.0079). Older age was inversely associated with postoperative testosterone elevation in both groups. Improvements in nocturia were notable in both groups.

CONCLUSIONS

AFSPE of the prostate significantly elevates serum testosterone levels in men with BPO, particularly benefiting those initially with low levels. Age is a crucial factor influencing postoperative testosterone changes, indicating that younger patients may benefit more from this intervention. AFSPE offers a promising approach for improving hormonal health in BPO patients, alongside alleviating urinary symptoms.

Falsely elevated serum testosterone measurements resulting from testosterone topical gel contamination of the venipuncture site: Case Series and retrospective review

Testosterone as replacement therapy for male hypogonadism or as gender-affirming hormone therapy for transgender and non-binary patients has increased worldwide. Commonly used formulations of testosterone include intramuscular, transdermal patch, and topical gel, each of which has differing pharmacokinetics and practical challenges. In monitoring testosterone serum concentrations, contamination of the phlebotomy site by testosterone topical gel can lead to supraphysiologic (>1000 ng/dL or 34.7 nmol/L) serum concentrations of testosterone, as demonstrated in a few published case reports. The frequency of this issue is currently not known. The present study involves a retrospective search over a 13-year period across all clinical sites at an academic medical center. Out of 578 unique patients using testosterone topical gel, a total of 48 patients had at least 1 testosterone serum concentration exceed 1000 ng/dL. Documentation in the electronic health record revealed 7 patients where contamination of the phlebotomy site by topical gel was strongly supported as the cause of supraphysiologic testosterone serum concentrations. These included 5 males with primary hypogonadism, 1 male with panhypopituitarism, and a non-binary patient with gender dysphoria. The high testosterone concentrations prompted further work-up, including retesting and endocrinology consultation. There were additional cases of high testosterone serum concentration that may have been falsely elevated due to gel contamination but without sufficient supporting evidence available in the health record. Overall, we present 7 cases of spuriously high testosterone concentrations strongly suspected to be due to venipuncture performed near or at the location of prior testosterone gel application. Gel contamination should be considered as a possible cause of otherwise unexplained high testosterone serum concentration in patients receiving topical testosterone gel formulations. Patient counseling and provider awareness of this potential cause of spuriously high testosterone serum concentrations is important.

Two Transgender Men Receiving Subdermal Testosterone Pellets for Gender Affirmation

Background/Objective

Testosterone treatment is employed in transgender men to help them affirm their gender. Our objective is to report the cases of 2 transgender men who received subdermal testosterone pellets as the mode of testosterone administration.

Case Report

Both patients presented for discussion of testosterone therapy. Patient 1 was a 47-year-old transgender male. He had bilateral mastectomy and total abdominal hysterectomy with bilateral salpingo-oophorectomy (TAH-BSO). Physical exam was significant for obesity. He was on injectable testosterone for 9 years and experienced voice deepening, facial hair growth, temporal hair thinning, and increased skin oiliness, but was interested in a long-acting testosterone formulation. Pellets were well tolerated, but the patient ultimately chose to return to injections. Patient 2 was a 20-year-old transgender male with no history of gender-affirming surgeries. Physical exam was pertinent for a thin, masculinized individual. He started on testosterone gel, but switched to weekly injections, on which he experienced voice deepening, increased skin oiliness and cessation of menses. Due to pain with injections and desire for a long-acting formulation, he elected to try pellets.

Discussion

The dose of testosterone pellets used in transgender men are similar to those employed for testosterone replacement in hypogonadal cisgender men.

Conclusion

Subdermal testosterone pellets may be suitable as a means of delivering testosterone in transgender men, but the 2 cases reported here do not permit firm conclusions. Given the widespread use of testosterone for gender affirmation in transgender men, a prospective controlled study of subdermal testosterone pellets seems indicated.

Trans Dermal Testosterone Compared to Intramuscular Testosterone for Young Males with Delayed Puberty: A PRISMA Guided Systematic Review

Background

Challenges in selecting the right formulation of testosterone (TE) for young males with delayed puberty (DP) arise from the fact that there is limited evidence based guidelines in recommending the most efficient and safe formulation of TE.

Objective

To evaluate the existing evidence and systematically review the interventional effects of transdermal TE to other modes of TE administration for the treatment of DP among young and adolescent males.

Methods

All types of methodologies published in English were searched from the data sources including MEDLINE, Embase, Cochrane Reviews, Web of Science, AMED and Scopus from 2015 till 2022. Boolean operators with keywords "types of TE", "modes of TE administration", "DP", "transdermal TE", "constitutional delay of growth and puberty, (CDGP)" "adolescent boys" and "hypogonadism" to optimize the search results. The main outcomes of concern were optimal serum TE level, body mass index, height velocity, testicular volume, pubertal stage (Tanner), The secondary outcomes included in this study were adverse events and patient satisfaction.

Results

After screening 126 articles, 39 full texts were reviewed. Only five studies could be included after careful screening and rigid quality assessments. Most studies were at high or unclear risk of bias with short duration and follow up periods. Only one study was a clinical trial covering all the outcomes of interests.

Conclusion

This study points out the favorable effects of transdermal TE treatment for DP in boys, while the existence of the vast gap in research needs to be acknowledged. Despite the utmost demand in an appropriate TE treatment for young males with DP, scarce efforts and trials are being undertaken to provide clear clinical guidance of treatment. Quality of life, cardiac events, metabolic parameters, coagulation profiles are important aspects of the treatment are overlooked and under evaluated in most studies.

Systematic Review Registration

PROSPERO CRD 42022369699.

Does Patient-Applied Testosterone Replacement Therapy Pose Risk for Blood Pressure Elevation? Circadian Medicine Perspectives

We reviewed medication package inserts, US Food and Drug Administration (FDA) reports, and journal publications concerning the 10 nonbiosimilar patient-applied (PA) testosterone (T) replacement therapies (TRTs) for intraday serum T patterning and blood pressure (BP) effects. Blood T concentration is circadian rhythmic in young adult eugonadal males, being highest around awakening and lowest before bedtime. T level and 24 h variation are blunted in primary and secondary hypogonadism. Utilized as recommended, most PA-TRTs achieve nonphysiologic T 24 h patterning. Only Androderm^® , an evening PA transdermal patch, closely replicates the normal T circadian rhythmicity. Accurate determination of risk for BP elevation and hypertension (HTN) by PA-TRTs is difficult due to limitations of office BP measurements (OBPM) and suboptimal methods and endpoints of ambulatory BP monitoring (ABPM). OBPM is subject to "White Coat" pressor effect resulting in unrepresentative BP values plus masked normotension and masked HTN, causing misclassification of approximately 45% of trial participants, both before and during treatment. Change in guideline-recommended diagnostic thresholds over time causes misclassification of an additional approximately 15% of participants. ABPM is improperly incorporated into TRT safety trials. It is done for 24 h rather than preferred 48 h; BP is oversampled during wakefulness, biasing derived 24 h mean values; 24 h mean systolic and diastolic BP (SBP, DBP) are inappropriate primary outcomes, because of not being best predictors of risk for major acute cardiovascular events (MACE); "daytime" and "nighttime" BP means referenced to clock time are reported rather than biologically relevant wake-time and sleep-time BP means; most importantly, asleep SBP mean and dipping, strongest predictors of MACE, are disregarded. © 2022 American Physiological Society. Compr Physiol 12: 1-20, 2022.