GYNAECOSID TABLET

Indications

• Hormone replacement therapy in postmenopausal women
• Management of menopausal symptoms such as hot flashes and vaginal atrophy
• Contraceptive use in combination with progestins

Dosage

Children: Refer to the BNF for Children for specific paediatric dosing information.

Adults: Refer to the BNF for specific adult dosing guidelines based on the indication.

Mechanism of action

Methyloestradiol exerts its effects by binding to estrogen receptors (ERs) in target tissues, leading to the activation of estrogen-responsive genes. This interaction promotes the development and maintenance of female reproductive tissues, as well as influencing other physiological processes associated with estrogen, including bone density and lipid metabolism. The mechanism involves complex intracellular signaling pathways that modulate gene expression related to cell proliferation and differentiation.

Pharmacodynamics

Methyloestradiol demonstrates typical estrogen-like effects, influencing a variety of tissues including the uterus, breast, and bone. It plays a critical role in regulating the menstrual cycle, promoting endometrial growth, and maintaining secondary sexual characteristics. Additionally, it has protective effects on bone density, reducing the risk of osteoporosis post-menopause.

Pharmacokinetics

Methyloestradiol is well absorbed following oral administration. It undergoes extensive hepatic metabolism, primarily via conjugation, resulting in various metabolites. The drug's half-life is approximately 10 to 20 hours, allowing for once-daily dosing in many cases. It is excreted mainly in urine as metabolites. The pharmacokinetics may vary based on individual patient factors including hepatic function.

Contra-indications

• Known or suspected pregnancy
• Active venous thromboembolism
• Severe hepatic impairment
• History of hormone-related cancers
• Uncontrolled hypertension
• Severe migraines or migraine with aura
• Hypersensitivity to methyloestradiol or any of its components

Adverse effects

• Nausea
• Breast tenderness
• Headache
• Mood changes
• Weight gain
• Edema
• Thromboembolic events
• Increased risk of endometrial hyperplasia
• Vaginal bleeding

Interactions

• Anticonvulsants (e.g., phenytoin, carbamazepine) may decrease effectiveness
• Antibiotics may affect the metabolism of methyloestradiol
• Rifampicin may decrease plasma levels of methyloestradiol
• St. John's Wort may reduce efficacy

Precautions

• Monitor for signs of thromboembolism
• Regular gynecological examinations recommended
• Use with caution in patients with a history of depression
• May affect glucose tolerance
• Caution in patients with a history of liver disease

Pregnancy

Methyloestradiol is contraindicated in pregnancy due to potential risks to the fetus.

Breast-feeding

Methyloestradiol is excreted in breast milk, and caution is advised when administering to nursing mothers.

Storage

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

Formulations

• Tablets containing 0.5 mg methyloestradiol
• Tablets containing 1 mg methyloestradiol

Indications

• Anemia
• Cachexia
• Severe weight loss
• Muscle wasting diseases

Dosage

Children: Refer to BNF for Children for specific paediatric dosing.

Adults: Refer to BNF for specific dosing guidelines.

Mechanism of action

Methyloestrenolone functions by binding to androgen receptors in target tissues, which subsequently activates specific genes responsible for protein synthesis. This anabolic action enhances muscle growth and nitrogen retention, leading to increased muscle mass and strength.

Pharmacodynamics

As an anabolic steroid, methyloestrenolone exhibits potent anabolic effects that include promoting protein synthesis, enhancing nitrogen retention, and stimulating erythropoiesis. These properties make it beneficial for patients needing to gain weight or improve their physical condition following illness or injury.

Pharmacokinetics

Methyloestrenolone is well-absorbed when taken orally and undergoes extensive hepatic metabolism. It has a relatively long half-life, allowing for once-daily dosing in some cases. The drug is metabolized primarily in the liver, and its metabolites are excreted through urine. Its pharmacokinetic profile supports its effectiveness as an anabolic agent.

Contra-indications

• Pregnancy
• Breastfeeding
• History of thromboembolic disorders
• Active liver disease
• Hormone-sensitive cancers
• Severe hypertension

Adverse effects

• Nausea
• Vomiting
• Abdominal cramps
• Weight gain
• Fluid retention
• Menstrual irregularities
• Increased risk of thromboembolic events
• Changes in mood or behavior

Interactions

• Anticoagulants - may increase the risk of bleeding
• Corticosteroids - may increase the risk of fluid retention
• Cyclosporine - may increase serum concentrations of cyclosporine
• Antiepileptics - may affect hormone levels and efficacy of contraceptives

Precautions

• Monitor for signs of thromboembolic events
• Evaluate liver function prior to treatment and periodically during treatment
• Consider risks versus benefits in patients with cardiovascular disease
• Use with caution in patients with diabetes or a history of depression

Pregnancy

Methyloestrenolone is contraindicated in pregnancy due to potential harm to the fetus.

Breast-feeding

Methyloestrenolone is contraindicated during breastfeeding as it may affect milk production and composition.

Storage

Store in a cool, dry place, away from direct sunlight. Keep out of reach of children.

Formulations

• Oral tablets