Tibolone

Tibolone is a synthetic steroid medicine primarily used in Hormone Replacement Therapy (HRT) for postmenopausal women.

Here is a detailed breakdown of the information you requested:

1. What is Tibolone (explain in detail/different name)?

• Tibolone is a synthetic steroid that acts as a Selective Tissue Estrogenic Activity Regulator (STEAR), a Selective Estrogen Enzyme Modulator (SEEM), or a Tissue-specific Receptor and Intracrine Mediator (TRIM). More encompassingly, it's also been called a Selective Progestogen, Estrogen, and Androgen Regulator (SPEAR).

• Different Names/Trade Names: The most common brand name is Livial. Other trade names include Tibella, Tibofem, and others. Its code name in development was ORG-OD-14.

• Mechanism: Tibolone is a prodrug that is rapidly metabolized in the body into three main active metabolites:

  • 3α-hydroxytibolone and 3β-hydroxytibolone: These metabolites primarily exert estrogenic activity, especially in tissues like bone, the brain, and the vagina.

  • Δ4-tibolone (Delta-4-tibolone): This metabolite binds to the progesterone and androgen receptors, providing progestogenic and androgenic activity.

  • This tissue-selective activity allows Tibolone to provide benefits similar to combined HRT (estrogen + progestogen) but with a different safety profile, particularly in the breast and endometrium.

2. Side Effects and Benefits (Pros and Cons)

3. Dosage with What Frequency?

• Standard Dosage: 2.5 mg

• Frequency: One tablet daily (taken orally), usually at the same time each day, without interruption.

• Note: It is generally recommended to use the lowest effective dose for the shortest duration necessary to control symptoms.

4. Half-Life and Detection Time (how many days/weeks)?

• Elimination Half-Life: The half-life of the parent drug, Tibolone, is approximately 45 hours. The two major estrogenic metabolites (3α/3β-OH-tibolone) have a shorter half-life of 6 to 8 hours.

• Detection Time: Information on the specific detection window for anti-doping purposes (in days/weeks) is not readily available in general medical literature and would depend on the specific testing method, cut-off levels, and substance tested (parent drug or metabolites). As a synthetic steroid, its use could lead to a positive test in sports if banned.

5. What are Sterogenic Progestronic Prolactin Affects?

Tibolone's effects on these receptors and hormones are complex and tissue-selective:

• Estrogenic Affects (via 3α-OH and 3β-OH metabolites):

  • Acts as an agonist on estrogen receptors (ERs), especially in bone, brain, and vagina. This is responsible for climacteric symptom relief and bone protection.

  • Acts as an antagonist or has minimal effect in the endometrium and breast in many women, which is the basis for its tissue selectivity (though risks remain).

• Progestogenic Affects (via Δ4-tibolone metabolite):

  • Acts as an agonist on the progesterone receptor (PR). This activity provides a protective effect on the endometrium, counteracting the estrogenic effect, which helps to prevent endometrial hyperplasia and cancer.

• Androgenic Affects (via Δ4-tibolone metabolite):

  • Acts as an agonist on the androgen receptor (AR). This contributes to improved libido and potentially beneficial effects on muscle/mood. It also significantly decreases Sex Hormone-Binding Globulin (SHBG) levels, leading to increased levels of free (biologically active) testosterone.

• Prolactin Affects:

  • Tibolone and its metabolites have been shown to elevate prolactin expression in human endometrial stromal cells in in vitro studies, suggesting a progestogen receptor-mediated effect in that specific tissue. The clinical impact on systemic circulating prolactin levels is not consistently a primary focus of its therapeutic profile.

6. What is Anabolic Androgenic Ratio (give number like digits not e/g 1:10)?

• The anabolic:androgenic ratio is a common measurement for classic anabolic-androgenic steroids (AAS).

• While Tibolone has definite androgenic activity (contributing to its effects on libido and muscle), quantitative data expressing a specific, universally accepted anabolic:androgenic ratio (e.g., 5:1) for Tibolone, comparable to those used for AAS, is not typically reported in standard medical literature.

• Its classification is as a tissue-selective steroid with mixed estrogenic, progestogenic, and androgenic effects, rather than a primarily anabolic agent.