Total T Levels Research Articles

Pharmacokinetic Evaluation and Dosing of Subcutaneous Testosterone Pellets

Subcutaneous testosterone (T) pellets are a viable treatment modality for hypogonadism. Optimal dosing, frequency of reimplantation, and long-term safety of T pellets remain incompletely elucidated parameters. A retrospective review of 273 patients treated for hypogonadism using subcutaneous T pellets was performed. Serum total T (TT), free T (FT), and estradiol (E2) levels were analyzed as a function of time from implantation, number of pellets implanted (6-9 or 10-12), body mass index (BMI; <25 or ≥ 25 kg/m(2)), number of implantations (≤ 4 rounds, 501 insertions), and preimplantation T levels (<300 or ≥ 300 ng/dL). T decay was determined using linear regression and TT levels immediately postimplantation and the time for TT levels to reach 300 ng/dL extrapolated for all variables. Mean patient age ± SD was 56 ± 12.6 years. Baseline TT level was 328 ± 202 ng/dL, FT 9.49 ± 27.8 pg/mL, and E2 25.1 ± 17.3 pg/mL. Extrapolated TT and FT peaks were lower in men receiving 6 to 9 pellets than men receiving 10 to 12, although decay rates differed insignificantly. E2 levels rose significantly in men receiving 10 to 12 but not 6 to 9 pellets. Men with BMI ≥ 25 kg/m(2) attained lower TT peaks with slower decay than men with BMI <25 kg/m(2) receiving 10 to 12 pellets, although 300 ng/dL TT levels were reached at approximately 100 days in both groups. No differences were seen in decay rates for men with multiple implant rounds, and no differences in T peaks or decay rates were seen in men with preimplant T level <300 or ≥ 300 ng/dL. One patient developed erythrocytosis, and no prostate-specific antigen recurrences were observed in men with prostate cancer treated with T pellets. Men with BMI <25 kg/m(2) should receive fewer pellets, and reimplantation for all men should occur 100 to 120 days after prior implantation. Men receiving 10 to 12 pellets have higher E2 levels, potentially reflecting increased aromatization of T. Reimplantation and preimplantation TT levels do not affect pellet decay kinetics.

1494 PHARMACOKINETIC EVALUATION AND DOSING OF SUBCUTANEOUS TESTOSTERONE PELLETS

You have accessJournal of UrologySexual Function/Dysfunction/Andrology: Medical and Non-Surgical Therapy1 Apr 20121494 PHARMACOKINETIC EVALUATION AND DOSING OF SUBCUTANEOUS TESTOSTERONE PELLETS Alexander W. Pastuszak, Harsha Mittakanti, Lissette Gomez, Joceline S. Liu, Larry I. Lipshultz, and Mohit Khera Alexander W. PastuszakAlexander W. Pastuszak Houston, TX More articles by this author , Harsha MittakantiHarsha Mittakanti Houston, TX More articles by this author , Lissette GomezLissette Gomez Houston, TX More articles by this author , Joceline S. LiuJoceline S. Liu Chicago, IL More articles by this author , Larry I. LipshultzLarry I. Lipshultz Houston, TX More articles by this author , and Mohit KheraMohit Khera Houston, TX More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.2016AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Subcutaneous testosterone (T) pellets are a viable treatment modality for hypogonadism. Optimal dosing, frequency of reimplantation, long-term safety, and post-implantation physiologic decay of hormone levels resulting from T pellets remain incompletely elucidated parameters. METHODS A retrospective review of 273 patients treated for hypogonadism using subcutaneous T pellets between 2008-2011 was performed. Sixty-five of these patients had a history of prostate cancer (CaP). Serum total T (TT), free T (FT), and estradiol (E) levels were analyzed as a function of time, number of pellets implanted (6-9 or 10-12), body mass index (BMI) (<25 or ≥25), number of implantations (up to 4 rounds, 501 insertions) and pre-implantation T levels (<300 or ≥300ng/dL). Linear regression analysis of the Log of hormone levels was used to determine curve fit equations, which were subsequently used to extrapolate decay curves for serum hormone levels. Hemoglobin (Hgb), hematocrit (Hct), and PSA levels were also assessed and analyzed as a function of time after implantation. RESULTS Mean±SD subject age was 56±12.6 years. Baseline TT was 328±202 ng/dL, FT 9.49±27.8 pg/mL and E 25.1±17.3 pg/mL. Extrapolated TT and FT peaks were significantly lower in men receiving 6-9 pellets than 10-12, though decay rates differed insignificantly. E levels rose significantly in men receiving 10-12, but not 6-9 pellets. Men with BMI≥25 attained lower TT peaks with slower decay than those with BMI<25 receiving 10-12 pellets, though 300ng/dL TT levels were reached at ∼100 days in both groups. No differences were seen in rates of decay for men receiving multiple implants, and no differences in T peaks or rates of decay were seen in men with pre T <300 or ≥300ng/dL. Increases in both Hgb (mean increase 0.42±0.94 g/dL, p<0.0001) and Hct (1.97±2.97%, p<0.0001) were observed, and one patient developed erythrocytosis requiring phlebotomy. No significant increases in PSA in men with or without CaP were observed, and no PSA recurrences were observed in men with CaP. CONCLUSIONS Men with lower BMI should receive fewer pellets and re-implantation should occur 100-120 days after prior implantation. More pellets result in increased aromatization of T to E. Serum testosterone levels prior to implantation and at re-implantation do not affect pellet decay kinetics. Importantly, T pellets appear safe, with small effects on Hgb and Hct, and without evidence of significant effects on PSA or progression or recurrence of CaP when used in men with a history of the disease. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e605 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Alexander W. Pastuszak Houston, TX More articles by this author Harsha Mittakanti Houston, TX More articles by this author Lissette Gomez Houston, TX More articles by this author Joceline S. Liu Chicago, IL More articles by this author Larry I. Lipshultz Houston, TX More articles by this author Mohit Khera Houston, TX More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Comparison of salivary versus serum testosterone levels in postmenopausal women receiving transdermal testosterone supplementation versus placebo

Clinical assessment of androgen action and its correlation to testosterone levels in women has been challenging. The current gold standard for measuring biologically active testosterone (T) is serum free T by equilibrium dialysis. Alternative methods are desirable due to the cost, complexity, and limited availability of the equilibrium dialysis method. Salivary testing has been proposed as a possible substitute for serum testing. This study compared salivary versus serum measurements of total T (TT), bioavailable T (BT; consisting of free T [FT] and albumin-bound T), and FT from samples collected simultaneously in women who were either receiving transdermal T patch supplementation (300 microg/d) or a placebo patch. Naturally and surgically postmenopausal women receiving concomitant hormone therapy were recruited to participate in a 24- to 52-week phase III trial of a 300 microg/day transdermal T patch for the treatment of hypoactive sexual desire disorder. Initial analysis demonstrated high correlations between TT, BT, and FT levels (r = 0.776-0.855). However, there was no correlation with salivary T levels for any of the serum T subtypes (r = 0.170-0.261). After log transformation, salivary T correlated modestly with BT (r = 0.436, P < 0.001), FT (r = 0.452, P < 0.001), and TT (r = 0.438, P < 0.001). Although salivary testing of T concentrations is an appealing alternative because it is inexpensive and noninvasive, our results do not support the routine use of salivary T levels in postmenopausal women.

Endocrine environment of benign prostatic hyperplasia: prostate size and volume are correlated with serum estrogen concentration.

Estrogen plays an important role in the development of benign prostatic hyperplasia (BPH), as has been shown in both experimental and clinical studies. T determine the endocrine environment of BPH, serum total testosterone (Total-T), free testosterone (Free-T), and estradiol (E2) conceptions were measured, and the relationship between these levels and prostate size and volume was analyzed. Blood samples were collected from subjects who attended the mass screening for prostate disease performed by our institute. No significant correlations were found between Total-T levels, Free-T levels, and prostate size, as determined by digital rectal examination. However, E2 levels and the ratios for E2 levels and the ratios for E2/Total-T and E2/Free-T were significantly correlated with prostate size. To confirm these relationships, prostate volume was calculated from transrectal ultrasonographic images. E2 levels and these two ratios were, indeed, highly correlated with prostate volume. These results suggest that an estrogen-dominant environment plays an important role in the development of BPH.