Pharmacology and drugs in reproductive and child health

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Pharmacology and drugs in Reproductive and Child Health can be organized into these major areas:

Contraception and family planning
- Combined and progestin-only hormonal contraceptives
- Emergency contraception
- Injectable and implantable contraceptives
- Intrauterine devices
- Medical eligibility, adverse effects, contraindications
Drugs used in pregnancy
- Antenatal corticosteroids
- Iron, folic acid, calcium, and micronutrient supplementation
- Antiemetics, antacids, and drugs for common pregnancy conditions
- Medicines considered safe, avoided, or contraindicated in pregnancy
Labour and postpartum medicines
- Uterotonics: oxytocin, misoprostol, ergometrine, carboprost
- Drugs for induction and augmentation of labour
- Tocolytics for preterm labour
- Magnesium sulfate for eclampsia
- Tranexamic acid and management of postpartum haemorrhage
Hypertensive disorders and medical disease in pregnancy
- Antihypertensives for severe hypertension
- Anticonvulsant therapy in eclampsia
- Anticoagulants and insulin use in pregnancy
Gynaecological pharmacology
- Drugs for abnormal uterine bleeding
- Ovulation induction and infertility therapy
- Medical treatment of endometriosis and fibroids
- Drugs for pelvic inflammatory disease and sexually transmitted infections
Neonatal pharmacology
- Neonatal resuscitation medicines
- Vitamin K, vaccines, antibiotics, surfactant
- Treatment of neonatal seizures, jaundice, and apnea
Essential paediatric medicines
- Fluid therapy and oral rehydration
- Antipyretics and analgesics
- Antibiotics for common childhood infections
- Antimalarials, antituberculars, and antiparasitic medicines
- Drugs for asthma, seizures, anaemia, and malnutrition
Child-health programmes and preventive medicines
- Immunization schedules and vaccine pharmacology
- Vitamin A, zinc, iron, deworming
- ORS and zinc in acute diarrhoea
- Paediatric dose calculation and safe prescribing principles

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This spans seven large modules. I can cover one module thoroughly at a time, including key drugs, mechanism, indications, adverse effects, contraindications, and important doses where appropriate.

Drugs in pregnancy
Labour, preterm labour, eclampsia, and postpartum haemorrhage
Hypertension, diabetes, thrombosis, and other medical disorders in pregnancy
Gynaecological drugs: AUB, infertility, endometriosis, fibroids, PID/STIs
Neonatal pharmacology
Essential paediatric medicines
Child-health prevention: vaccines, vitamin A, zinc, iron, deworming, ORS

Together, these cover safe prescribing in pregnancy, obstetric emergency medicines, neonatal care, treatment of common childhood illnesses, and preventive child-health interventions.

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Pharmacology and drugs in Reproductive and Child Health can be organized into these major areas:

Contraception and family planning
- Combined and progestin-only hormonal contraceptives
- Emergency contraception
- Injectable and implantable contraceptives
- Intrauterine devices
- Medical eligibility, adverse effects, contraindications
Drugs used in pregnancy
- Antenatal corticosteroids
- Iron, folic acid, calcium, and micronutrient supplementation
- Antiemetics, antacids, and drugs for common pregnancy conditions
- Medicines considered safe, avoided, or contraindicated in pregnancy
Labour and postpartum medicines
- Uterotonics: oxytocin, misoprostol, ergometrine, carboprost
- Drugs for induction and augmentation of labour
- Tocolytics for preterm labour
- Magnesium sulfate for eclampsia
- Tranexamic acid and management of postpartum haemorrhage
Hypertensive disorders and medical disease in pregnancy
- Antihypertensives for severe hypertension
- Anticonvulsant therapy in eclampsia
- Anticoagulants and insulin use in pregnancy
Gynaecological pharmacology
- Drugs for abnormal uterine bleeding
- Ovulation induction and infertility therapy
- Medical treatment of endometriosis and fibroids
- Drugs for pelvic inflammatory disease and sexually transmitted infections
Neonatal pharmacology
- Neonatal resuscitation medicines
- Vitamin K, vaccines, antibiotics, surfactant
- Treatment of neonatal seizures, jaundice, and apnea
Essential paediatric medicines
- Fluid therapy and oral rehydration
- Antipyretics and analgesics
- Antibiotics for common childhood infections
- Antimalarials, antituberculars, and antiparasitic medicines
- Drugs for asthma, seizures, anaemia, and malnutrition
Child-health programmes and preventive medicines
- Immunization schedules and vaccine pharmacology
- Vitamin A, zinc, iron, deworming
- ORS and zinc in acute diarrhoea
- Paediatric dose calculation and safe prescribing principles

At a high level, reproductive pharmacology focuses on preventing conception, ensuring safe pregnancy and childbirth, and treating obstetric emergencies. Child-health pharmacology prioritizes weight-based dosing, prevention through immunization and supplementation, rapid treatment of infections, and safe fluid management.This spans seven large modules. I can cover one module thoroughly at a time, including key drugs, mechanism, indications, adverse effects, contraindications, and important doses where appropriate.

Drugs in pregnancy
Labour, preterm labour, eclampsia, and postpartum haemorrhage
Hypertension, diabetes, thrombosis, and other medical disorders in pregnancy
Gynaecological drugs: AUB, infertility, endometriosis, fibroids, PID/STIs
Neonatal pharmacology
Essential paediatric medicines
Child-health prevention: vaccines, vitamin A, zinc, iron, deworming, ORS

Together, these cover safe prescribing in pregnancy, obstetric emergency medicines, neonatal care, treatment of common childhood illnesses, and preventive child-health interventions.

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postpartum hemorrhage AND uterotonic

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WHO recommendations postpartum haemorrhage prevention treatment oxytocin tranexamic acid magnesium sulfate preterm birth

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2. Labour, preterm labour, eclampsia, and postpartum haemorrhage

These medicines are used in supervised obstetric settings because incorrect dose, route, or timing can cause fetal distress, uterine rupture, severe hypotension, respiratory depression, or haemorrhage.

A. Drugs for induction and augmentation of labour

1. Oxytocin

Class: Uterotonic hormone
Mechanism: Activates oxytocin receptors in uterine smooth muscle, increasing intracellular calcium and producing rhythmic uterine contractions.

Uses

Induction of labour when delivery is indicated
Augmentation of inadequate uterine contractions
Active management of third stage of labour
Prevention and treatment of uterine-atony postpartum haemorrhage

Administration

For induction/augmentation: IV infusion through a controlled infusion pump, with gradual titration to contraction pattern and continuous fetal and uterine monitoring.
For prevention of PPH: commonly 10 IU IM or slow IV after birth, subject to local protocol.
For treatment of atonic PPH: IV infusion, often 20 to 40 IU in 1 L crystalloid, depending on protocol. Roberts and Hedges' Clinical Procedures in Emergency, p. 3949.

Adverse effects

Uterine tachysystole or hyperstimulation
Fetal hypoxia or fetal distress due to excessive contractions
Uterine rupture, especially with scarred uterus or obstruction
Hypotension with rapid IV bolus
Water intoxication and hyponatraemia with prolonged high-dose infusion because oxytocin has antidiuretic activity

Precautions/contraindications Do not induce or augment labour when vaginal delivery is contraindicated, for example placenta previa, transverse lie, cord prolapse, cephalopelvic disproportion, or certain prior uterine scars.

2. Prostaglandins for cervical ripening and induction

Drug	Main role	Important precautions
Dinoprostone	PGE2 preparation for cervical ripening before induction	Remove vaginal insert if tachysystole or fetal distress develops
Misoprostol	PGE1 analogue used for cervical ripening and induction, medical abortion, and PPH	Avoid for term induction in women with a previous cesarean or major uterine surgery because of rupture risk
Carboprost	PGF2-alpha analogue, mainly for refractory atonic PPH	Avoid in asthma; can cause bronchospasm
Ergometrine/methylergometrine	Potent uterotonic, mainly for PPH	Avoid in hypertension, pre-eclampsia, or cardiac disease

Misoprostol

Mechanism: Causes cervical softening and uterine contractions through prostaglandin receptors.

Uses

Cervical ripening and induction of labour
Induction in fetal demise, according to gestational age
Treatment or prevention of PPH where appropriate
Medical abortion and management of miscarriage, under protocol

Common adverse effects

Fever and shivering
Nausea, vomiting, diarrhoea
Uterine tachysystole
Fetal distress in labour

Key exam point: Misoprostol is effective for induction, but should generally not be used for term induction in a patient with a previous cesarean delivery or uterine surgery. Textbook of Family Medicine 9e, p. 501.

Dinoprostone

Mechanism: PGE2-mediated cervical ripening and increased myometrial activity.

Use: Unfavourable cervix when induction is necessary.

Adverse effects: Uterine hyperstimulation, nausea, vomiting, diarrhoea, fever, and rarely fetal compromise.

B. Drugs for preterm labour

Goals of treatment

Tocolysis does not permanently stop preterm birth. Its principal purpose is usually to delay delivery briefly, often up to about 48 hours, to:

complete antenatal corticosteroids,
allow transfer to a centre with neonatal care,
give magnesium sulfate for fetal neuroprotection when indicated.

Preterm labour means contractions before 37 weeks with cervical change. Contractions without progressive dilation or effacement do not necessarily require tocolysis. Textbook of Family Medicine 9e, p. 495.

1. Nifedipine

Class: Calcium-channel blocker
Mechanism: Reduces calcium entry into myometrial cells, decreasing uterine contraction.

Use: Common first-line tocolytic in many settings.

Adverse effects

Headache
Flushing
Dizziness
Hypotension
Palpitations

Avoid/caution: Maternal hypotension, significant cardiac disease. Careful monitoring is needed if combined with magnesium sulfate because both can impair neuromuscular and cardiovascular function.

2. Beta-agonists: terbutaline, salbutamol

Mechanism: Beta-2 receptor stimulation relaxes uterine smooth muscle.

Use: Sometimes used for acute uterine tachysystole or short-term tocolysis.

Adverse effects

Maternal tachycardia and palpitations
Tremor, anxiety
Hyperglycaemia
Hypokalaemia
Pulmonary oedema
Fetal tachycardia

Important: Prolonged or routine maintenance use is avoided because maternal cardiovascular toxicity can be serious.

3. Atosiban

Class: Oxytocin-receptor antagonist
Mechanism: Blocks oxytocin-mediated uterine contractions.

Use: Tocolysis in some countries and institutions.

Adverse effects: Usually fewer cardiovascular adverse effects than beta-agonists; nausea, headache, dizziness, and injection-site reactions can occur.

4. Indomethacin

Class: NSAID, prostaglandin synthesis inhibitor
Mechanism: Inhibits cyclo-oxygenase, reducing prostaglandin-mediated uterine activity.

Use: Short-course tocolysis, usually earlier in gestation.

Fetal concerns

Premature constriction or closure of the ductus arteriosus
Oligohydramnios from reduced fetal renal perfusion
Potential neonatal complications if used late or for too long

Key point: Its use is generally restricted to earlier gestation and short duration.

5. Magnesium sulfate: not a routine tocolytic

Magnesium sulfate relaxes smooth muscle, but it is not preferred solely as a tocolytic. Its main obstetric roles are:

Prevention and treatment of seizures in severe pre-eclampsia/eclampsia
Fetal neuroprotection when very preterm birth is anticipated

6. Antenatal corticosteroids

Drugs

Betamethasone: 12 mg IM, two doses 24 hours apart
Dexamethasone: 6 mg IM, four doses 12 hours apart

Mechanism: Accelerate fetal lung maturation and surfactant production.

Benefits when preterm delivery is likely

Reduced neonatal respiratory distress syndrome
Reduced intraventricular haemorrhage
Reduced necrotizing enterocolitis
Improved neonatal survival

Creasy & Resnik's Maternal-Fetal Medicine, p. 887.

C. Eclampsia and severe pre-eclampsia

Magnesium sulfate

Class: Anticonvulsant and neuromuscular depressant
Mechanism: Reduces neuromuscular transmission and central neuronal excitability. It is the first-line medicine for preventing recurrent seizures in eclampsia and for seizure prophylaxis in pre-eclampsia with severe features.

Indications

Eclampsia
Pre-eclampsia with severe features
Fetal neuroprotection when early preterm delivery is imminent

Common IV regimen

A commonly used regimen is:

Loading: 4 g IV slowly over about 5 minutes
Maintenance: 1 to 2 g/hour IV infusion

If convulsions recur, an additional IV dose may be administered according to institutional protocol.

Monitoring during magnesium therapy

Monitor:

Respiratory rate
Deep tendon reflexes, especially patellar reflex
Urine output
Maternal consciousness
Serum magnesium concentration when renal impairment or toxicity is suspected

Magnesium toxicity

Finding	Significance
Loss of deep tendon reflexes	Early clinical sign of toxicity
Respiratory depression	Severe toxicity
Oliguria	Magnesium accumulation risk
Bradycardia, cardiac conduction defects, cardiac arrest	Very severe toxicity

Antidote: Calcium gluconate 10%, 10 mL IV slowly in suspected significant magnesium toxicity, with airway and ventilatory support.

Caution/contraindications

Myasthenia gravis
Significant renal impairment or oliguria, requiring dose adjustment and close monitoring
Serious cardiac conduction disease

Magnesium sulfate is more effective than phenytoin for prevention or treatment of eclamptic seizures. Swanson's Family Medicine Review, p. 1444.

Other supportive drugs in eclampsia

Antihypertensives

Used for acute severe hypertension to reduce maternal stroke risk:

Labetalol IV
Hydralazine IV
Immediate-release nifedipine orally

The goal is controlled lowering of dangerously elevated blood pressure, not sudden excessive hypotension that may compromise uteroplacental blood flow.

If seizures persist despite magnesium

Consider:

Recurrent seizure management with additional magnesium per protocol
Airway protection and oxygenation
Alternative causes such as intracranial haemorrhage, especially with focal/recurrent seizures or persistent reduced consciousness
Delivery after maternal stabilization

Definitive treatment of eclampsia is delivery, but the patient must first be stabilized. Eclampsia itself is not automatically an indication for cesarean delivery. Creasy & Resnik's Maternal-Fetal Medicine, p. 1736.

D. Postpartum haemorrhage

Definition and major causes

PPH is excessive bleeding after birth and should be managed as an emergency. The classic causes are the 4 Ts:

Tone: uterine atony, the most common cause
Trauma: genital tract laceration, uterine rupture, haematoma
Tissue: retained placenta or placental fragments
Thrombin: coagulopathy

Medication is most useful for uterine atony, but clinicians must actively identify trauma, retained tissue, and coagulopathy.

Immediate first-response bundle

Management is simultaneous, not stepwise waiting:

Call for help and assess blood loss
Uterine massage
Establish IV access and resuscitate with fluids/blood products as needed
Give uterotonic medicine
Give tranexamic acid early
Examine for genital tract trauma and retained tissue
Escalate to balloon tamponade, surgery, or transfusion if bleeding continues

WHO recommends a first-response bundle including uterine massage, an oxytocic, tranexamic acid, IV fluids, examination of the genital tract, and escalation of care, as summarized in its consolidated PPH guidance.

1. Oxytocin: first-line uterotonic

Use: First-line treatment for atonic PPH.

Dose: Protocol dependent. A common regimen is 20 to 40 IU in 1 L crystalloid by IV infusion. Roberts and Hedges' Clinical Procedures in Emergency, p. 3949.

Adverse effects: Hypotension if given rapidly IV, tachysystole, and water intoxication with excessive prolonged doses.

2. Ergometrine or methylergometrine

Mechanism: Produces sustained strong uterine contraction by acting on smooth muscle receptors.

Typical dose: Methylergometrine 0.2 mg IM, repeated only according to protocol.

Adverse effects

Nausea and vomiting
Hypertension
Vasospasm
Chest pain or myocardial ischaemia in susceptible patients

Contraindicated in

Hypertension
Pre-eclampsia/eclampsia
Significant cardiac or peripheral vascular disease

3. Carboprost tromethamine

Mechanism: PGF2-alpha analogue causing powerful uterine contraction.

Use: Atonic PPH not responding adequately to oxytocin, after considering contraindications.

Typical dose: 250 micrograms IM, repeatable at intervals according to protocol, with a maximum total dose often 2 mg. Creasy & Resnik's Maternal-Fetal Medicine, p. 954.

Adverse effects

Bronchospasm
Diarrhoea, vomiting
Fever
Hypertension

Contraindication: Asthma is the key contraindication.

4. Misoprostol

Mechanism: Prostaglandin analogue that increases uterine tone.

Use: Prevention or treatment of PPH, particularly where injectable uterotonics are unavailable or as an additional uterotonic.

Adverse effects

Fever
Shivering
Diarrhoea
Nausea and vomiting

It is inexpensive, heat-stable, and useful where cold-chain storage or IV access is limited, but it commonly causes fever and shivering.

5. Tranexamic acid

Class: Antifibrinolytic
Mechanism: Inhibits fibrin breakdown by blocking plasminogen activation, helping stabilize formed clots. It does not replace uterotonics because it does not correct uterine atony.

Indication: PPH after vaginal birth or cesarean birth, in addition to standard care.

WHO regimen

1 g IV over 10 minutes, given within 3 hours of birth
Give a second 1 g IV dose if bleeding continues after 30 minutes or restarts within 24 hours

This regimen is stated in the WHO PPH guideline.

Important point: Do not delay tranexamic acid while waiting for uterotonics to fail if PPH is diagnosed. Earlier administration is more effective.

Quick comparison table

Clinical situation	Main medicines	Core caution
Induction/augmentation	Oxytocin, dinoprostone, misoprostol	Monitor for tachysystole and fetal distress
Preterm labour	Nifedipine, indomethacin, atosiban; selected beta-agonist use	Aim for short delay, not indefinite suppression of labour
Threatened early preterm birth	Betamethasone or dexamethasone	Supports fetal lung maturation
Severe pre-eclampsia/eclampsia	Magnesium sulfate plus antihypertensive if severe BP	Monitor reflexes, respiration, urine output
Atonic PPH	Oxytocin, carboprost, ergometrine, misoprostol, TXA	Choose uterotonic based on asthma and hypertension history
Persistent PPH	TXA plus blood products and procedural/surgical escalation	Seek trauma, retained tissue, and coagulopathy

High-yield exam points

Oxytocin is first-line for induction, augmentation, and uterine-atony PPH.
Misoprostol can cause fever, shivering, diarrhoea, and uterine hyperstimulation.
Avoid misoprostol for term induction in a scarred uterus because of rupture risk.
Nifedipine is a commonly used tocolytic; monitor for maternal hypotension.
Antenatal corticosteroids improve outcomes when preterm birth is likely.
Magnesium sulfate is first-line for eclampsia, not phenytoin or diazepam.
Calcium gluconate is the antidote for magnesium toxicity.
Avoid ergometrine in hypertension/pre-eclampsia.
Avoid carboprost in asthma.
Give tranexamic acid early, within 3 hours of birth, for PPH.

Recent evidence also includes a 2025 Cochrane network meta-analysis of uterotonics for PPH prevention, PMID 40237648. Drug selection and dosing should still follow the facility's obstetric emergency protocol and the mother's contraindications.

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