A 32-year-old mother at 2 weeks postpartum reports inadequate milk supply and poor infant weight gain. Clinical examination shows no signs of infection or engorgement. What is the drug of choice to enhance lactation?

Explanation

## Pharmacological Enhancement of Lactation **Key Point:** Domperidone is the preferred drug of choice for inadequate milk supply (lactation failure) in the postpartum period due to its superior safety profile compared to metoclopramide. ### Mechanism of Domperidone in Lactation Domperidone enhances lactation through **peripheral dopamine (D₂) antagonism**: 1. **Peripheral D₂ receptor blockade** → increases prolactin secretion from the anterior pituitary 2. **Minimal CNS penetration** → significantly reduces the risk of extrapyramidal side effects and depression Prolactin is the primary hormone maintaining milk production after lactogenesis II is established. ### Domperidone: Pharmacology & Safety | Parameter | Details | |-----------|----------| | **Dose** | 10–20 mg three times daily for 4–8 weeks | | **Onset** | 3–4 days; peak effect at 2–3 weeks | | **Milk transfer** | <0.1% of maternal dose; very safe for infant | | **Efficacy** | Increases milk volume significantly in responsive mothers | | **Contraindications** | Cardiac arrhythmias, prolonged QT interval | **High-Yield:** Domperidone is preferred over metoclopramide as the galactagogue of choice because: - **Minimal CNS penetration** → far lower risk of extrapyramidal effects, tardive dyskinesia, and maternal depression - Better tolerability for long-term use - Lower infant exposure through breast milk (<0.1% of maternal dose) - Endorsed by major lactation authorities (Academy of Breastfeeding Medicine Protocol #9) **Clinical Pearl:** Before prescribing lactogenic drugs, always rule out: - Poor latch or positioning (most common cause of low supply) - Inadequate milk removal frequency - Maternal illness, stress, or dehydration - Infant problems (tongue tie, poor suck) Drugs are adjuncts to, not replacements for, proper breastfeeding technique. ### Comparison of Prolactin-Enhancing Agents | Drug | Mechanism | Use in Lactation | Notes | |------|-----------|------------------|-------| | **Domperidone** | D₂ antagonist (peripheral) | **Drug of choice for low supply** | Minimal CNS effect; safest profile | | Metoclopramide | D₂ antagonist (central + peripheral) | Second-line alternative | Higher risk of extrapyramidal effects, depression | | Bromocriptine | D₂ agonist | **Contraindicated** | Suppresses lactation; used to stop it | | Cabergoline | D₂ agonist (long-acting) | **Contraindicated** | Suppresses lactation; used for prolactinoma | **Warning:** Do NOT confuse the direction of dopamine action: - **Dopamine agonists** (bromocriptine, cabergoline) → ↓ prolactin → **suppress** lactation - **Dopamine antagonists** (metoclopramide, domperidone) → ↑ prolactin → **enhance** lactation ### Why Domperidone Over Metoclopramide? Per KD Tripathi (*Essentials of Medical Pharmacology*, 8th ed.) and the Academy of Breastfeeding Medicine (ABM Protocol #9, 2018), domperidone is the **preferred galactagogue** because its peripheral restriction means: 1. No tardive dyskinesia risk with prolonged use 2. No maternal depression or anxiety 3. Negligible infant CNS exposure via milk Metoclopramide, while effective, carries a Black Box Warning (FDA) for tardive dyskinesia with prolonged use, making it a second-line agent. **Mnemonic:** **DOM**peridone = **D**rug **O**f choice for **M**ilk enhancement (peripheral D₂ antagonist → ↑ prolactin, minimal CNS risk).