Dydrogesterone

• Menstrual Disorders:
  Treatment of menstrual irregularities such as amenorrhea, irregular menstruation, and dysfunctional uterine bleeding due to luteal phase deficiency.
• Secondary Amenorrhea:
  For restoration of menstrual cycles in women with secondary amenorrhea related to progesterone deficiency.
• Infertility Related to Luteal Phase Defect:
  Support of the luteal phase in assisted reproductive technologies and infertility treatments.
• Threatened or Habitual Miscarriage:
  Prevention and treatment of threatened miscarriage and recurrent pregnancy loss related to progesterone insufficiency.
• Endometriosis:
  Management of endometriosis symptoms and lesion regression.
• Hormone Replacement Therapy (HRT):
  Used in combination with estrogens to oppose estrogen-induced endometrial hyperplasia in menopausal hormone therapy.
• Other Off-label Uses:
  Treatment of premenstrual syndrome and dysmenorrhea.

• Adults:
• Menstrual Disorders:
  10–20 mg daily in divided doses, typically from day 14 to 25 of the menstrual cycle.
• Secondary Amenorrhea:
  10 mg twice daily for 10 days; may be repeated if no withdrawal bleeding.
• Luteal Phase Support:
  10–20 mg daily, usually starting mid-cycle until pregnancy is confirmed or during early pregnancy as indicated.
• Threatened Miscarriage:
  30–40 mg daily, divided doses, continuing up to 12 weeks gestation or as clinically required.
• Endometriosis:
  10 mg twice daily continuously or as directed by physician.
• Hormone Replacement Therapy:
  10 mg daily, usually for 12 to 14 days per cycle, combined with estrogen therapy.
• Pediatrics:
  Safety and efficacy not established.
• Elderly:
  Generally not indicated.
• Administration:
  Oral tablets taken with or without food.
• Renal/Hepatic Impairment:
  No specific dose adjustment; caution advised in severe hepatic impairment.

Dydrogesterone is a synthetic retroprogesterone that acts as a selective progesterone receptor agonist. It binds to progesterone receptors in target tissues such as the endometrium, modulating gene expression to promote secretory transformation of the endometrium, maintain pregnancy, and regulate the menstrual cycle. Unlike natural progesterone, dydrogesterone has minimal androgenic, estrogenic, or glucocorticoid activity, resulting in fewer side effects. It effectively mimics endogenous progesterone's role in preparing and maintaining the uterine lining and supporting pregnancy.

• Absorption:
  Well absorbed orally with high bioavailability.
• Distribution:
  Widely distributed; plasma protein binding approximately 96%.
• Metabolism:
  Extensively metabolized in the liver to inactive metabolites via reduction and hydroxylation.
• Half-life:
  Approximately 5–7 hours.
• Elimination:
  Excreted mainly in urine as metabolites; minor biliary excretion.

• Pregnancy:
  Classified as FDA Category B; considered relatively safe for use in pregnancy for luteal support and prevention of miscarriage under medical supervision.
• Lactation:
  Limited data; likely excreted in breast milk in small amounts. Use with caution during breastfeeding.

• Primary Therapeutic Class: Progestogen
• Subclass: Synthetic retroprogesterone derivative

• Known hypersensitivity to dydrogesterone or any excipients.
• Undiagnosed vaginal bleeding.
• Active thrombophlebitis or thromboembolic disorders.
• Severe hepatic dysfunction or liver disease.
• Breast carcinoma or other hormone-dependent cancers.

• Thromboembolic Disorders:
  Use with caution in patients with history or risk factors for venous thromboembolism.
• Hormone-sensitive Tumors:
  Monitor carefully in patients with breast or other hormone-dependent cancers.
• Liver Disease:
  Avoid in severe hepatic impairment.
• Depression:
  May exacerbate pre-existing depression.
• Fluid Retention:
  Use cautiously in patients with conditions aggravated by fluid retention (e.g., cardiac or renal impairment).

Common:

• Headache
• Breast tenderness or pain
• Nausea
• Menstrual irregularities
• Bloating or fluid retention

Less Common/Rare:

• Allergic reactions (rash, pruritus)
• Mood changes, depression
• Thromboembolism (very rare)
• Weight changes

• No major clinically significant drug interactions reported.
• Enzyme inducers such as rifampicin, carbamazepine may reduce dydrogesterone efficacy.
• Caution with other hormonal therapies or drugs affecting coagulation.

• Endorsed by international gynecological guidelines for luteal phase support in assisted reproduction.
• Recent studies confirm safety in pregnancy for threatened miscarriage management.
• No significant changes in dosing recommendations in recent guidelines.

• Store at 20°C to 25°C (68°F to 77°F).
• Protect from moisture and light.
• Keep tablets in original container tightly closed.
• Keep out of reach of children.