I have rich textbook information. Let me now compile the comprehensive viva-focused drug list from my knowledge and textbook data.
Here is a comprehensive list of drugs in Gynaecology and Obstetrics organized by category, ideal for viva preparation:
Drugs in Gynaecology and Obstetrics - Complete Viva Guide
1. OXYTOCICS (Uterotonic Drugs)
Drugs that stimulate uterine contractions. Used for induction of labour, PPH prevention/treatment.
| Drug | Class | Key Points |
|---|
| Oxytocin | Posterior pituitary hormone | DOC for induction of labour; causes rhythmic contractions; given IV infusion; risk: water intoxication (antidiuretic effect), hypotension |
| Ergometrine (Ergonovine) | Ergot alkaloid | Sustained tonic contraction; used in PPH; NOT used for induction (causes fetal distress); CI: hypertension, pre-eclampsia |
| Syntometrine | Oxytocin + Ergometrine combo | Used for active management of 3rd stage of labour |
| Carboprost (PGF2α) | Prostaglandin | Used in PPH refractory to oxytocin/ergometrine; bronchospasm is main SE; CI: asthma |
| Misoprostol (PGE1) | Prostaglandin | Oral/sublingual/vaginal; used for induction, PPH, medical abortion; heat stable (no cold chain needed) |
| Dinoprostone (PGE2) | Prostaglandin | Cervical ripening and induction of labour |
| Methylergometrine | Ergot alkaloid | Postpartum uterine involution; used orally postpartum |
2. TOCOLYTICS (Drugs to Stop Preterm Labour)
Used to delay delivery to allow corticosteroids to act and/or transfer to tertiary centre.
| Drug | Mechanism | Notes |
|---|
| Nifedipine | Calcium channel blocker | First-line tocolytic; most commonly used; SE: hypotension, headache, flushing |
| Ritodrine | β2-agonist | First approved tocolytic; SE: tachycardia, hypokalemia, pulmonary edema; less used now |
| Terbutaline | β2-agonist | Subcutaneous use; similar SEs to ritodrine |
| Salbutamol | β2-agonist | IV use for tocolysis |
| Indomethacin | COX inhibitor (NSAID) | Used <32 weeks; risk of premature closure of ductus arteriosus and oligohydramnios |
| Atosiban | Oxytocin receptor antagonist | Most selective tocolytic; fewer SEs; expensive |
| Magnesium Sulfate | Calcium antagonist | Used <32 weeks for fetal neuroprotection; monitor for respiratory depression (antidote: calcium gluconate) |
| Nitroglycerin | NO donor | Transdermal patches; used in some protocols |
3. ANTIHYPERTENSIVES IN PREGNANCY
Emergency (Acute Severe Hypertension - BP ≥160/110):
| Drug | Route | Notes |
|---|
| Labetalol | IV | Alpha + beta blocker; drug of choice for acute severe HTN in pregnancy |
| Hydralazine | IV | Vasodilator; older agent; risk of lupus-like syndrome |
| Nifedipine | Oral (IR) | Calcium channel blocker; widely used; monitor for hypotension if combined with MgSO4 |
| Sodium Nitroprusside | IV | Last resort; cyanide toxicity risk to fetus |
Chronic/Maintenance Antihypertensives in Pregnancy:
| Drug | Notes |
|---|
| Methyldopa | DOC for chronic HTN in pregnancy; centrally acting; safe |
| Labetalol | Oral; good safety profile |
| Nifedipine (SR) | Oral; commonly used |
| Amlodipine | Less data but used |
| Atenolol | Avoid - IUGR risk |
| ACE inhibitors (Captopril, Enalapril) | CONTRAINDICATED - fetotoxic (renal agenesis, oligohydramnios, fetal death) |
| ARBs (Losartan etc.) | CONTRAINDICATED |
4. ANTICONVULSANTS IN PREGNANCY (Eclampsia)
| Drug | Notes |
|---|
| Magnesium Sulfate | DOC for eclampsia prophylaxis and treatment; Pritchard regime / Zuspan regime; antidote: calcium gluconate 10%; therapeutic level 4-7 mEq/L; monitor patellar reflex (lost at 7 mEq/L), respiration (depressed at >10), cardiac arrest (>15) |
| Diazepam | Second line; crosses placenta; neonatal respiratory depression |
| Phenytoin | Inferior to MgSO4; teratogenic (fetal hydantoin syndrome) |
5. DRUGS FOR MEDICAL ABORTION
| Drug | Use | Mechanism |
|---|
| Mifepristone (RU-486) | Medical termination | Antiprogesterone (progesterone receptor antagonist); given 48h before misoprostol |
| Misoprostol (PGE1) | With or without mifepristone | Vaginal/sublingual; causes contractions; used alone if mifepristone unavailable |
| Methotrexate | Ectopic pregnancy, early abortion | Folic acid antagonist; used in unruptured ectopic (<3.5 cm, no cardiac activity) |
| Potassium Chloride | Selective fetal reduction | Intracardiac injection |
6. CORTICOSTEROIDS (Fetal Lung Maturity)
| Drug | Dose | Notes |
|---|
| Betamethasone | 12 mg IM × 2 doses 24h apart | Preferred over dexamethasone (less neonatal periventricular leukomalacia) |
| Dexamethasone | 6 mg IM × 4 doses 12h apart | Alternative; used when betamethasone unavailable |
Given 24-34 weeks gestation (some guidelines extend to 36+6 weeks) to reduce RDS, IVH, NEC in neonate.
7. HORMONAL DRUGS IN GYNAECOLOGY
Estrogens
| Drug | Use |
|---|
| Ethinyl estradiol | Combined OCP |
| Conjugated equine estrogens | HRT (Premarin) |
| Estradiol | HRT patches/gels |
| Diethylstilbestrol (DES) | Historical; caused clear cell adenocarcinoma in daughters |
Progestogens
| Drug | Use |
|---|
| Progesterone (natural) | Luteal phase support, threatened abortion, preterm birth prevention |
| Medroxyprogesterone acetate (MPA) | HRT, contraception (Depo-Provera), endometriosis |
| Norethisterone | Combined OCP, dysfunctional uterine bleeding |
| Levonorgestrel | Combined/progestogen-only OCP; IUS (Mirena) |
| Dydrogesterone | Threatened/recurrent abortion; luteal support |
| Hydroxyprogesterone caproate | Preterm birth prevention (weekly IM injection) |
Anti-Progestogens
| Drug | Use |
|---|
| Mifepristone | Abortion, fibroid treatment, uterine priming |
| Ulipristal acetate | Emergency contraception (ella®); uterine fibroids |
Anti-Estrogens / SERMs
| Drug | Use | Notes |
|---|
| Clomiphene citrate | Ovulation induction (PCOS) | Anti-estrogenic at hypothalamus → ↑GnRH → ↑FSH/LH; risk of OHSS and multiple pregnancy |
| Tamoxifen | Breast cancer; ovulation induction | SERM - antagonist in breast, partial agonist in uterus (risk of endometrial Ca) |
| Raloxifene | Osteoporosis | SERM - no uterine stimulation; reduces breast cancer risk |
| Fulvestrant | Metastatic breast cancer | Pure estrogen antagonist |
GnRH Analogues
| Drug | Use | Notes |
|---|
| Leuprolide (Leuprorelin) | Endometriosis, fibroids, IVF down-regulation, precocious puberty | Initial flare → then downregulation; SE: hypoestrogenic effects, hot flashes, bone loss |
| Buserelin | Same as above | |
| Goserelin (Zoladex) | Same; also breast/prostate cancer | SC implant |
| Nafarelin | Intranasal; endometriosis | |
| Cetrorelix / Ganirelix | GnRH antagonist; IVF | Immediate suppression (no flare); used in antagonist IVF protocols |
8. DRUGS FOR ENDOMETRIOSIS
| Drug | Class | Notes |
|---|
| Danazol | Androgen (synthetic) | Pseudomenopause; SE: androgenic (acne, hirsutism, voice change, clitoromegaly), hepatotoxic |
| GnRH agonists | (see above) | Add-back therapy needed to prevent bone loss |
| Combined OCP | Estrogen-progestogen | Continuous use (no pill-free interval); first-line medical Rx |
| Progestogens | MPA, norethisterone, dienogest | |
| Dienogest | Progestogen | Selective progestogen; approved for endometriosis |
| Levonorgestrel-IUS | Local progestogen | Reduces menstrual blood loss and endometriosis pain |
| NSAIDs | COX inhibitors | Pain management |
9. CONTRACEPTIVES
Combined Oral Contraceptive Pills (COCPs)
- Estrogen (ethinyl estradiol) + Progestogen
- Mechanism: Inhibit ovulation (mainly); also thicken cervical mucus, thin endometrium
- CI: WHO MEC 4 - smoker >35 yrs, migraine with aura, thrombophilia, hepatic disease, personal history of breast cancer
- Non-contraceptive benefits: Reduce PID, ovarian/endometrial cancer risk, treat dysmenorrhea, acne, PCOS
Emergency Contraception
| Drug | Mechanism | Timing |
|---|
| Levonorgestrel (Plan B) | Inhibit/delay ovulation | Within 72h (effective up to 120h) |
| Ulipristal acetate (ella) | Selective progesterone receptor modulator | Within 120h; superior at 72-120h |
| Copper IUD | Spermicidal, anti-implantation | Within 5 days; most effective EC |
Long-Acting Reversible Contraception (LARC)
| Method | Drug/Device |
|---|
| Copper IUD | Non-hormonal |
| Levonorgestrel-IUS (Mirena) | 52 mg LNG; lasts 5-7 years |
| Etonogestrel implant (Nexplanon) | Subdermal; lasts 3 years |
| DMPA (Depo-Provera) | Medroxyprogesterone 150 mg IM q12 weeks |
10. DRUGS FOR POLYCYSTIC OVARIAN SYNDROME (PCOS)
| Drug | Use | Mechanism |
|---|
| Metformin | Insulin sensitizer | Reduces hyperinsulinemia → reduces androgens; helps ovulation; used in PCOS-associated infertility |
| Clomiphene citrate | Ovulation induction | Anti-estrogen at hypothalamus |
| Letrozole | Ovulation induction | Aromatase inhibitor; now preferred over clomiphene (better live birth rates) |
| Combined OCP | Regulate cycles, treat hyperandrogenism | |
| Spironolactone | Anti-androgen | Hirsutism, acne in PCOS |
| Cyproterone acetate | Anti-androgen | Hirsutism, acne |
| Eflornithine (Vaniqa) | Hirsutism | Topical; inhibits ornithine decarboxylase in hair follicles |
11. DRUGS FOR OVARIAN STIMULATION / INFERTILITY / ART
| Drug | Class | Use |
|---|
| FSH (Follitropin α/β) | Gonadotropin | Controlled ovarian hyperstimulation |
| LH (Lutropin α) | Gonadotropin | With FSH in IVF |
| hCG (Choriogonadotropin) | LH analogue | "Trigger shot" to induce final oocyte maturation |
| Progesterone | Progestogen | Luteal phase support in IVF |
| Bromocriptine / Cabergoline | Dopamine agonist | Hyperprolactinemia-induced anovulation; also used to prevent/treat OHSS |
| Cabergoline | Dopamine agonist D2 | Preferred over bromocriptine (fewer SE); prevents OHSS |
| GnRH agonist/antagonist | (see above) | Down-regulation or antagonist protocols for IVF |
12. DRUGS FOR UTERINE FIBROIDS (Leiomyomata)
| Drug | Notes |
|---|
| GnRH agonists (Leuprolide, Goserelin) | Reduce fibroid size by 30-60%; used preoperatively; max 6 months |
| Ulipristal acetate (Esmya) | SPRM; reduces fibroid volume; bleeding from fibroid |
| Tranexamic acid | Antifibrinolytic; reduces heavy menstrual bleeding |
| NSAIDs | Pain and menorrhagia |
| Levonorgestrel-IUS | Reduces HMB associated with fibroids |
| Combined OCP | Menstrual regulation |
| Iron supplementation | Correct anemia from HMB |
13. DRUGS FOR HEAVY MENSTRUAL BLEEDING (Menorrhagia)
| Drug | Notes |
|---|
| Tranexamic acid | First-line non-hormonal; antifibrinolytic; 1g TDS during menstruation |
| Mefenamic acid | NSAID; also reduces dysmenorrhea |
| Combined OCP | Reduces blood loss by 40-50% |
| Levonorgestrel-IUS (Mirena) | Reduces blood loss by 80-90%; first-line intrauterine option |
| Norethisterone | Oral progestogen; cycle day 5-26 |
| GnRH agonists | Short-term before surgery |
14. DRUGS IN PREGNANCY - ANTENATAL SUPPLEMENTS
| Drug | Use | Dose |
|---|
| Folic acid | Neural tube defect prevention | 0.4 mg/day routinely; 5 mg/day high-risk (prior NTD, anti-epileptics, diabetes) |
| Iron (ferrous sulfate) | Iron deficiency anaemia | 200 mg TDS (60 mg elemental iron) |
| Calcium | Preeclampsia prevention (in low-calcium populations) | 1.5-2 g/day |
| Vitamin D | Deficiency prevention | 400-1000 IU/day |
| Low-dose aspirin | Preeclampsia prevention (high-risk) | 75-150 mg/day from <16 weeks |
| Heparin (LMWH) | Thromboprophylaxis | Enoxaparin; does NOT cross placenta |
| Pyridoxine (Vit B6) | Hyperemesis gravidarum | With doxylamine |
| Thiamine (Vit B1) | Wernicke's encephalopathy in hyperemesis | IV |
15. ANTIEMETICS IN PREGNANCY
| Drug | Safety | Notes |
|---|
| Doxylamine + Pyridoxine | Safe | First-line (Diclegis/Bonjesta) |
| Metoclopramide | Safe (caution) | Dopamine antagonist |
| Ondansetron | Caution (possible cleft palate risk in 1st trimester) | 5-HT3 antagonist; used for refractory cases |
| Promethazine | Safe | Antihistamine |
| Ginger | Safe | Non-pharmacological |
| Prednisolone | Last resort in hyperemesis gravidarum | |
16. ANTIMICROBIALS IN PREGNANCY
Safe Antibiotics:
- Penicillins (amoxicillin, ampicillin) - safe all trimesters
- Cephalosporins - safe
- Erythromycin (not estolate) - safe
- Azithromycin - relatively safe
- Clindamycin - safe
- Metronidazole - avoid 1st trimester; safe 2nd/3rd
Contraindicated/Avoid:
| Drug | Risk |
|---|
| Tetracyclines | Dental staining, bone growth inhibition |
| Fluoroquinolones | Cartilage damage |
| Aminoglycosides | Ototoxicity (8th nerve) |
| Sulfonamides | Kernicterus near term |
| Chloramphenicol | Gray baby syndrome |
| Trimethoprim | Folate antagonist (1st trimester) |
Antifungals:
- Clotrimazole (topical) - safe
- Fluconazole - avoid systemic in 1st trimester (cardiac defects)
- Nystatin (topical) - safe
17. ANTICOAGULANTS IN PREGNANCY
| Drug | Safety | Notes |
|---|
| LMWH (Enoxaparin, Dalteparin) | Safe | DOC; does NOT cross placenta; used for DVT/PE and antiphospholipid syndrome |
| Unfractionated Heparin | Safe | Used peripartum (shorter half-life); antidote: protamine sulfate |
| Warfarin | AVOID especially 6-12 weeks | Warfarin embryopathy (nasal hypoplasia, stippled epiphyses); causes fetal hemorrhage; crosses placenta |
| DOACs (rivaroxaban, apixaban) | CONTRAINDICATED | Insufficient safety data; teratogenic in animals |
| Aspirin (low dose) | Safe 2nd/3rd trimester | Avoid near term (premature closure of DA) |
18. ANTIDIABETIC DRUGS IN PREGNANCY
| Drug | Safety | Notes |
|---|
| Insulin | DOC | Does not cross placenta; all types (regular, NPH, analogues) |
| Metformin | Used (crosses placenta) | Used in GDM and PCOS; some concerns about fetal metabolic programming |
| Glibenclamide (Glyburide) | Used in some guidelines | Crosses placenta minimally; not universally recommended |
| Other sulfonylureas | AVOID | Fetal hypoglycemia |
| GLP-1 agonists, DPP4 inhibitors | AVOID | Insufficient safety data |
19. ANTI-EPILEPTICS IN PREGNANCY (Teratogenicity)
| Drug | Risk | Notes |
|---|
| Valproate | Highest risk - neural tube defects (1-2%), cognitive impairment, PCOS | AVOID in women of childbearing age if possible |
| Carbamazepine | Neural tube defects (0.5-1%) | Requires high-dose folic acid |
| Phenytoin | Fetal hydantoin syndrome (cleft lip, digital hypoplasia) | |
| Phenobarbitone | Cardiac defects, bleeding | Vitamin K given to neonate |
| Lamotrigine | Relatively safer | Preferred; levels change in pregnancy |
| Levetiracetam | Relatively safer | Increasingly used |
20. DRUGS FOR GESTATIONAL DIABETES / GLUCOSE TOLERANCE
| Drug | Notes |
|---|
| Insulin | First choice; see above |
| Metformin | Oral option; well studied in GDM |
21. DRUGS FOR LABOUR ANALGESIA
| Drug | Route | Notes |
|---|
| Pethidine (Meperidine) | IM/IV | Opioid; neonatal respiratory depression (antidote: naloxone); causes nausea |
| Fentanyl | IV/epidural | Faster onset; less neonatal effect |
| Epidural (Bupivacaine + fentanyl) | Epidural | Gold standard for labour analgesia |
| Nitrous oxide (Entonox) | Inhalation | 50% N2O + 50% O2; self-administered |
| Remifentanil PCA | IV | Ultra-short acting; needs monitoring |
22. DRUGS FOR POSTPARTUM HAEMORRHAGE (PPH)
Used in stepwise approach:
- Oxytocin - 10 IU IV/IM (first line)
- Ergometrine / Syntometrine - CI in hypertension
- Carboprost (Hemabate) - 250 mcg IM every 15-90 min (max 8 doses); CI asthma
- Misoprostol - 600-800 mcg sublingual/rectal; for resource-limited settings
- Tranexamic acid - 1g IV within 3 hours (WOMAN trial); reduces PPH mortality
- Recombinant Factor VIIa - last resort
23. DRUGS FOR CERVICAL RIPENING / INDUCTION
| Drug | Route | Notes |
|---|
| Dinoprostone (PGE2) | Vaginal pessary / gel | Standard cervical ripening |
| Misoprostol | Vaginal / oral | Off-label but widely used; cheaper |
| Mifepristone | Oral | Used in some protocols with misoprostol |
| Mechanical methods | Foley catheter, balloon | Non-pharmacological |
| Oxytocin | IV infusion | Once cervix is ripe (Bishop score ≥6) |
24. THYROID DRUGS IN PREGNANCY
| Drug | Notes |
|---|
| Levothyroxine | Hypothyroidism; safe; requirements increase in pregnancy |
| Propylthiouracil (PTU) | Preferred in 1st trimester hyperthyroidism; risk of hepatotoxicity |
| Carbimazole/Methimazole | Used 2nd/3rd trimester; aplasia cutis risk in 1st trimester |
| Radioactive iodine | CONTRAINDICATED in pregnancy |
25. GLUCOCORTICOIDS IN PREGNANCY
| Drug | Use |
|---|
| Betamethasone / Dexamethasone | Fetal lung maturity (see above) |
| Hydrocortisone | Adrenal crisis; surgical stress |
| Prednisone / Prednisolone | Autoimmune conditions (SLE, ITP); relatively safe as prednisolone is inactivated by placenta |
| Dexamethasone | Crosses placenta; for fetal conditions (e.g., congenital adrenal hyperplasia) |
Key Viva Questions to Prepare:
- DOC for eclampsia - Magnesium sulfate
- DOC for induction of labour - Oxytocin
- DOC for chronic HTN in pregnancy - Methyldopa
- DOC for acute severe HTN in pregnancy - Labetalol (IV)
- DOC for ectopic pregnancy (medical) - Methotrexate
- Antidote for MgSO4 toxicity - Calcium gluconate 10% (10 mL IV)
- DOC for PPH (1st line) - Oxytocin
- Tocolytic with most SE - β-mimetics (ritodrine, terbutaline)
- Most selective tocolytic - Atosiban
- Drug that reduces PPH mortality - Tranexamic acid (WOMAN trial)
- Safest anticoagulant in pregnancy - LMWH (does not cross placenta)
- Most teratogenic anticonvulsant - Valproate
- Ovulation induction 1st line (PCOS) - Letrozole (superseding clomiphene)
- Drug causing fetal hydantoin syndrome - Phenytoin
- Drug causing warfarin embryopathy - Warfarin (6-12 weeks gestation)
Sources: Creasy & Resnik's Maternal-Fetal Medicine, Berek & Novak's Gynecology, Katzung's Basic & Clinical Pharmacology - combined with current clinical practice guidelines.
