FEMIGEL

Dosage

Children: Refer to the BNF for Children for specific dosing recommendations.

Adults: Refer to the BNF for specific dosing recommendations.

Mechanism of action

The exact mechanism of action for Hemi is not explicitly detailed in the available resources, but compounds with similar structure may act by modulating neurotransmitter levels, inhibiting enzymes, or affecting cellular signaling pathways.

Pharmacodynamics

Hemi may exhibit pharmacodynamic properties that include modulation of neural activity or inhibition of specific biochemical pathways. Its effects could be dose-dependent and vary based on the therapeutic context.

Pharmacokinetics

The pharmacokinetic profile of Hemi, including absorption, distribution, metabolism, and excretion, is not well-documented in the provided resources. Generally, compounds in this class may undergo first-pass metabolism and have a variable half-life.

Dosage

Children: Refer to the specific formulation or active ingredient for dosing information.

Adults: Refer to the specific formulation or active ingredient for dosing information.

Mechanism of action

The mechanism of action of hemihydrate forms of drugs can vary widely depending on the specific compound. In many cases, the hemihydrate form enhances the solubility of the active ingredient, which facilitates its dissolution and absorption in the gastrointestinal tract.

Pharmacodynamics

Pharmacodynamics of hemihydrate compounds generally relates to the pharmacological effects that arise from the active drug once it is absorbed. The effects may vary based on the specific drug and its therapeutic target, but overall, the hemihydrate form aims to improve efficacy by ensuring adequate plasma concentrations are achieved more effectively than non-hydrated forms.

Pharmacokinetics

The pharmacokinetics of hemihydrate drugs typically demonstrate improved dissolution rates due to the presence of water, which can lead to increased absorption. This may result in quicker onset of action and modified half-lives. The specifics of absorption, distribution, metabolism, and excretion will depend on the active ingredient and its properties.

Pregnancy

Safety in pregnancy has not been established. Use only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

It is not known whether this drug is excreted in human milk. Caution should be exercised when administered to a nursing mother.

Storage

Store at room temperature, away from moisture and heat. Keep container tightly closed.

Indications

• Menopausal symptoms
• Hormone replacement therapy
• Osteoporosis prevention

Mechanism of action

Oestradiol functions by binding to estrogen receptors, specifically estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ), as well as the G Protein-coupled estrogen receptor (GPER). Upon binding, the receptor-ligand complex translocates to the nucleus, where it regulates gene transcription and the formation of messenger RNA. This process leads to the synthesis of specific proteins that mediate the effects of estradiol, including relief from vasomotor symptoms and urogenital atrophy, as well as beneficial impacts on bone density and lipid profiles.

Pharmacodynamics

Oestradiol alleviates vasomotor symptoms such as hot flashes and urogenital symptoms like vaginal dryness and dyspareunia. It positively influences bone density by inhibiting bone resorption, and it can enhance the plasma lipid profile. Additionally, estradiol stimulates hepatic synthesis of proteins like sex hormone-binding globulin (SHBG) and thyroid-binding globulin (TBG), while also suppressing follicle-stimulating hormone (FSH) production in the anterior pituitary gland. However, oestradiol can induce a hyper-coagulable state, increasing the risk of cardiovascular events, deep vein thrombosis (DVT), and stroke, especially in high-risk patients.

Pharmacokinetics

Oestradiol is rapidly absorbed after oral administration, with peak plasma concentrations reached within a few hours. It undergoes extensive first-pass metabolism in the liver, leading to a shorter half-life. Oestradiol is primarily metabolized via the cytochrome P450 enzyme system. It is excreted primarily in the urine as conjugated metabolites. The pharmacokinetics may vary based on the route of administration and the formulation used.

Contra-indications

• Known hypersensitivity to estradiol or any excipients in the formulation
• Current or history of thromboembolic disorders
• Severe liver disease
• Estrogen-dependent tumors
• Undiagnosed abnormal genital bleeding
• Pregnancy

Adverse effects

• Nausea
• Vomiting
• Headache
• Breast tenderness
• Mood changes
• Weight gain
• Vaginal bleeding
• Increased risk of thromboembolic events
• Hypertension

Interactions

• CYP450 enzyme inducers (e.g., rifampicin, carbamazepine) may decrease estradiol levels
• Anticonvulsants may affect estrogen metabolism
• Certain antibiotics may alter the efficacy of estrogen therapy
• Other hormone therapies may interact with estradiol

Precautions

• Monitor patients for signs of thromboembolic events
• Caution in patients with a history of hormone-dependent cancers
• Regular monitoring of blood pressure is recommended
• Consideration of risks in patients with cardiovascular disease

Pregnancy

Estradiol should not be used during pregnancy due to potential harm to the fetus.

Breast-feeding

Estradiol may pass into breast milk; caution is advised when administered to nursing mothers.

Storage

Store at room temperature, away from light and moisture. Keep out of reach of children.

Formulations

• Tablets
• Transdermal patches
• Injectable forms
• Topical gels

Mechanism of action

Estrogen is found in the the breast, uterine, ovarian, skin, prostate, bone, fat, and brain tissues. The main source of estrogen in adult women during the reproductive period of life is the ovarian follicle, which secretes 70 to 500 mcg of estradiol each day. After menopause, however, the majority of endogenous estrogen is produced by transformation of androstenedione (which is secreted by the adrenal cortex) to estrone in the peripheral tissues. Both estrone and its sulphate conjugated form, estrone sulphate, represent the most abundant estrogens found in postmenopausal women. Estradiol, however, is considerably more potent than estrone and estriol at the estrogen receptor (ER). As a result, the higher estrone concentration in postmenopausal population, can cause various undesirable effects. These effects may include hot flashes, chills, vaginal dryness, mood swings, irregular menstruation, and chills, in addition to sleep problems. Estradiol workings by binding to subtypes of the estrogen receptor: estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ). It also exerts potent agonism of G Protein-coupled estrogen receptor (GPER), which is recognized an important regulator of this drug's rapid effects. Once the estrogen receptor has bound to its ligand, it enters the nucleus of the target cell, regulating gene transcription and formation of of messenger RNA. This mRNA makes contact with ribosomes producing specific proteins that express the effect of estradiol upon the target cell. Agonism of estrogen receptors increases pro-estrogenic effects, leading to the relief of vasomotor and urogenital symptoms of a postmenopausal or low estradiol state. Endogenous estrogens are largely responsible for the development and maintenance of the female reproductive system and secondary sexual characteristics. Although circulating estrogens exist in a dynamic equilibrium of metabolic interconversions, estradiol is the principal intracellular human estrogen and is substantially more potent than its metabolites, estrone and estriol at the receptor level. ... After menopause, most endogenous estrogen is produced by conversion of androstenedione, secreted by the adrenal cortex, to estrone by peripheral tissues. Thus, estrone and the sulfate conjugated form, estrone sulfate, are the most abundant circulating estrogens in postmenopausal women. Estrogens act through binding to nuclear receptors in estrogen-responsive tissues. To date, two estrogen receptors have been identified. These vary in proportion from tissue to tissue. Circulating estrogens modulate the pituitary secretion of the gonadotropins, luteinizing hormone (LH) and follicle stimulating hormone (FSH), through a negative feedback mechanism. Estrogens act to reduce the elevated levels of these hormones seen in postmenopausal women. Estrogens have an important role in the reproductive, skeletal, cardiovascular, and central nervous systems in women, and act principally by regulating gene expression. Biologic response is initiated when estrogen binds to a ligand-binding domain of the estrogen receptor resulting in a conformational change that leads to gene transcription through specific estrogen response elements (ERE) of target gene promoters; subsequent activation or repression of the target gene is mediated through 2 distinct transactivation domains (ie, AF-1 and AF-2) of the receptor. The estrogen receptor also mediates gene transcription using different response elements (ie, AP-1) and other signal pathways. Recent advances in the molecular pharmacology of estrogen and estrogen receptors have resulted in the development of selective estrogen receptor modulators (eg, clomiphene, raloxifene, tamoxifen, toremifene), agents that bind and activate the estrogen receptor but that exhibit tissue-specific effects distinct from estrogen. Tissue-specific estrogen-agonist or -antagonist activity of these drugs appears to be related to structural differences in their estrogen receptor

Pharmacodynamics

Estradiol acts on the on the estrogen receptors to relieve vasomotor systems (such as hot flashes) and urogenital symptoms (such as vaginal dryness and dyspareunia). Estradiol has also been shown to exert favorable effects on bone density by inhibiting bone resorption. Estrogen appears to inhibit bone resorption and may have beneficial effects on the plasma lipid profile. Estrogens cause an increase in hepatic synthesis of various proteins, which include sex hormone binding globulin (SHBG), and thyroid-binding globulin (TBG). Estrogens are known to suppress the formation of follicle-stimulating hormone (FSH) in the anterior pituitary gland. **A note on hyper-coagulable state, cardiovascular health, and blood pressure** Estradiol may cause an increased risk of cardiovascular disease, DVT, and stroke, and its use should be avoided in patients at high risk of these conditions. Estrogen induces a hyper-coagulable state, which is also associated with both estrogen-containing oral contraceptive (OC) use and pregnancy. Although estrogen causes an increase in levels of plasma renin and angiotensin. Estrogen-induced increases in angiotensin, causing sodium retention, which is likely to be the mechanism causing hypertension after oral contraceptive treatment.