PT
● MODULE 14 / 20
Reproductive Hormones & Uterine Drugs
Relate feedback physiology to contraception, hormone treatment, labor and postpartum uterine activity.
Quick revision ↓ Medical Dictionary
FULL CHAPTER EXPLANATION
Deep Learning — Module 14
Read this section in sequence. It moves from drug targets to therapeutic effects, adverse reactions and safe use.
01
Reproductive feedback
Hypothalamic GnRH regulates pituitary LH and FSH, which govern gonadal steroid production and gametogenesis. Pulsatile GnRH can stimulate the axis; continuous agonist exposure eventually suppresses it after an initial flare. GnRH antagonists suppress without that initial agonist stimulation. Testosterone therapy replaces deficiency in selected patients but exogenous androgen can suppress gonadotropins and fertility. Anabolic steroid misuse carries endocrine, hepatic, cardiovascular and behavioral risks.
02
Contraceptive mechanisms
Combined estrogen-progestogen contraception suppresses ovulation and also alters cervical mucus and endometrium. Progestogen-only methods rely on several mechanisms, with ovulation suppression varying by preparation. Estrogen-containing products increase thrombotic risk and require individualized eligibility assessment. Enzyme-inducing drugs may reduce effectiveness of some hormonal methods. Adherence, missed-dose instructions and formulation matter; a single generic rule cannot cover all pills, implants, injections and intrauterine systems.
03
Other hormone therapies
Menopausal hormone therapy is selected for specific symptoms and individual risk; systemic estrogen generally requires endometrial protection with a progestogen when the uterus is present. Selective estrogen receptor modulators have tissue-dependent agonist and antagonist actions. Tamoxifen antagonizes estrogen effects in breast tissue but can stimulate the endometrium. Aromatase inhibitors reduce estrogen synthesis. Hormone-responsive cancers require receptor-informed, specialist treatment rather than nonspecific hormonal supplementation.
04
Uterotonics
Oxytocin activates uterine smooth-muscle receptors and promotes contraction. Excessive stimulation during labor can compromise fetal oxygenation and requires monitoring. Ergometrine increases uterine tone but can provoke hypertension and vasoconstriction. Prostaglandin agents have obstetric uses that depend on formulation and context. Uterotonics are not interchangeable: maternal blood pressure, asthma, gestation and the indication may change suitability. Postpartum hemorrhage management also requires assessment of cause and resuscitation.
05
Tocolysis and practical reasoning
Tocolytics aim to delay selected preterm labor situations long enough for other interventions; they do not guarantee prevention of preterm birth. Nifedipine reduces calcium entry into smooth muscle, and other agents have different mechanisms and contraindications. Drug decisions depend on gestation, membranes, infection and maternal-fetal status. Separate contraception, fertility treatment, pregnancy support, labor induction and hemorrhage treatment as distinct therapeutic goals with different benefit-risk balances.
High-Yield Revision
- Continuous and pulsatile GnRH exposure can have opposite long-term effects.
- Hormonal contraceptive interactions are formulation specific.
- Uterotonics require indication-specific maternal and fetal assessment.
Common Exam & Concept Pitfalls
- Exogenous testosterone is not a general treatment for male infertility.
- Do not assume all uterotonics have the same contraindications.
Sources & Further Reading
Curriculum scope checked 23 September 2026. These original study notes summarize established principles; current institutional guidance and product information govern clinical use. Faculty review is pending.
RAHBAR study structure: target → drug action → therapeutic use → adverse effects → monitoring. Use institutional curriculum and faculty guidance for local sequencing, practical requirements and assessment specifications.