Testosterone Heptanoate
Testosterone Heptanoate Uses, Dosage, Side Effects, Food Interaction and all others data.
Testosterone Heptanoate is an esterified variant of testosterone that comes as an injectable compound with a slow release rate. It is the first injectable ester preparation of testosterone. This slow release is achieved by the presence of the enanthate ester functional group attached to the testosterone molecule. This testosterone derivative was first approved on December 24, 1953.
In 2017, about 6.5 million retail prescriptions for testosterone therapy were filled . The majority of the prescriptions written were for injectable (66%) and topical (32%) testosterone products. As recent as 1 October 2018, the US FDA approved Antares Pharma Inc.'s Xyosted - a subcutaneous testosterone enanthate product for once-weekly, at-home self-administration with an easy-to-use, single dose, disposable autoinjector . As the first subcutaneous autoinjector product designed for testosterone replacement therapy, this innovative formulation removes transfer concerns commonly associated with testosterone gels and potentially reduces the need for in-office/in-clinic injection procedures that may inconvenience patients with frequent visits to the clinic .
Testosterone Heptanoate presents the same properties as its analog testosterone with the advantage that this molecule has a longer release rate and half-life. Administration of ester derivatives of testosterone as testosterone enanthate generates an increase in serum testosterone to levels reaching 400% from the baseline within 24 hours of administration. These androgen levels remain elevated for 3-5 days after initial administration. Continuous administration of testosterone enanthate shows a significant suppression of dihydrotestosterone, serum PSA, HDL and FSH, as well as a slight increase in serum estradiol. The levels of dihydrotestosterone and FSH can remain suppressed even 14 days after treatment termination. There are no changes in mood and sexual activity by the presence of testosterone enanthate.
| Trade Name | Testosterone Heptanoate |
| Generic | Testosterone enanthate |
| Testosterone enanthate Other Names | Testosterone enanthate, Testosterone heptanoate |
| Type | |
| Formula | C26H40O3 |
| Weight | Average: 400.594 Monoisotopic: 400.297745146 |
| Protein binding | Circulating testosterone is primarily bound in serum to sex hormone-binding globulin (SHBG) and albumin. Approximately 40% of testosterone in plasma is bound to SHBG, 2% remains unbound (free), and the rest is loosely bound to albumin and other proteins. |
| Groups | Approved |
| Therapeutic Class | |
| Manufacturer | |
| Available Country | |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
Testosterone Heptanoate is an androgen used to treat low or absent testosterone.
Testosterone Heptanoate in males is indicated as a replacement therapy in conditions associated with a deficiency or absence of endogenous testosterone. Some of the treated conditions are 1) primary hypogonadism, defined as testicular failure due to cryptorchidism, bilateral torsion, orchitis, vanishing testis syndrome or orchidectomy; 2) hypogonadotropic hypogonadism due to an idiopathic gonadotropin or luteinizing hormone-releasing hormone deficiency or due to a pituitary-hypothalamic injury from tumors, trauma or radiation, in this case it is important to accompany the treatment with adrenal cortical and thyroid hormone replacement therapy; 3) to stimulate puberty in patients with delayed puberty not secondary to a pathological disorder. If the conditions 1 and 2 occur prior to puberty, the androgen replacement therapy will be needed during adolescent years for the development of secondary sexual characteristics and prolonged androgen treatment might be needed it to maintain sexual characteristics after puberty.
In females, testosterone enanthate is indicated to be used secondarily in presence of advanced inoperable metastatic mammary cancer in women who are from one to five years postmenopausal. It has also been used in premenopausal women with breast cancer who have benefited from oophorectomy and are considered to have a hormone-responsive tumor.
Testosterone Heptanoate injections that are currently formulated for subcutaneous use are specifically indicated only for primary hypogonadism and hypogonadotropic hypogonadism . The use of such formulations is limited because the safety and efficacy of these subcutaneous products in adult males with late-onset hypogonadism and males less than 18 years old have not yet been established . Moreover, subcutaneously administered testosterone enanthate is indicated only for the treatment of men with hypogonadal conditions associated with structural or genetic etiologies, considering the medication could cause blood pressure increases that can raise the risk of major adverse cardiovascular events like non-fatal myocardial infarction, non-fatal stroke, and cardiovascular death .
Testosterone Heptanoate is also used to associated treatment for these conditions: Hypergonadotropic Hypogonadism, Hypogonadotrophic Hypogonadism, Puberty, Delayed, Inoperable, advanced, metastatic Breast Cancer
How Testosterone Heptanoate works
The effects of testosterone in humans and other vertebrates occur by way of two main mechanisms: by activation of the androgen receptor (directly or as DHT), and by conversion to estradiol and activation of certain estrogen receptors. Free testosterone (T) is transported into the cytoplasm of target tissue cells, where it can bind to the androgen receptor, or can be reduced to 5α-dihydrotestosterone (DHT) by the cytoplasmic enzyme 5α-reductase. DHT binds to the same androgen receptor even more strongly than T, so that its androgenic potency is about 2.5 times that of T. The T-receptor or DHT-receptor complex undergoes a structural change that allows it to move into the cell nucleus and bind directly to specific nucleotide sequences of the chromosomal DNA. The areas of binding are called hormone response elements (HREs), and influence transcriptional activity of certain genes, producing androgen effects.
Such activities are useful as endogenous androgens like testosterone and dihydrotestosterone are responsible for the normal growth and development of the male sex organs and for maintenance of secondary sex characteristics . These effects include the growth and maturation of the prostate, seminal vesicles, penis, and scrotum; the development of male hair distribution, such as facial, pubic, chest, and axillary hair; laryngeal enlargement, vocal cord thickening, and alterations in body musculature and fat distribution .
Male hypogonadism, a clinical syndrome resulting from insufficient secretion of testosterone, has two main etiologies . Primary hypogonadism is caused by defects of the gonads, such as Klinefelter’s syndrome or Leydig cell aplasia, whereas secondary hypogonadism is the failure of the hypothalamus (or pituitary) to produce sufficient gonadotropins (FSH, LH) .
Toxicity
Testosterone Heptanoate has been tested in preclinical carcinogenesis trials. In this studies, it is suggested that the exposure to this drug may increase the susceptibility to hematoma as well as the number of tumors and decrease the degree of differentiation of chemically induced carcinomas of the liver.
Testosterone Heptanoate is not indicated for use in females and is contraindicated in pregnant women. Testosterone is teratogenic and may cause fetal harm when administered to a pregnant woman based on data from animal studies and its mechanism of action.
During treatment with large doses of exogenous androgens, including testosterone enanthate, spermatogenesis may be suppressed through feedback inhibition of the hypothalamic-pituitary-testicular axis . Reduced fertility is observed in some men taking testosterone replacement therapy and the impact on fertility may be irreversible .
Safety and effectiveness of testosterone enanthate in pediatric patients less than 18 years old have not been established . Improper use may result in the acceleration of bone age and premature closure of epiphyses .
Geriatric patients treated with androgens may also be at risk for worsening of signs and symptoms of Benign Prostatic Hyperplasia .
Food Interaction
No interactions found.Volume of Distribution
The volume of distribution following intravenous administration of testosterone is of approximately 1 L/kg.
Elimination Route
The pharmacokinetic profile of testosterone enanthate was studied in a regime of multiple dosing and the testosterone level was reported to present a Cmax above 1200 ng/dl after 24 hours of the last dose. The concentration decreased sequentially until it reached 600 ng/dl after one week. The pharmacokinetic profile of testosterone enanthate presented differences depending on the administered dose in which the tmax was shifted to a range of 36-48 hours. The plasma testosterone level plateaued below the therapeutic range after 3-4 weeks. This reports showed that the different formulation of testosterone enanthate and testosterone cypionate generates a different profile and thus, they are not therapeutically equivalent.
Half Life
Testosterone Heptanoate presents a long half-life in the range of 7-9 days.
Elimination Route
About 90% of a dose of testosterone given intramuscularly is excreted in the urine as glucuronic and sulfuric acid conjugates of testosterone and its metabolites; about 6% of a dose is excreted in the feces, mostly in the unconjugated form. The inactivation of testosterone occurs primarily in the liver.
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