Pharmacology of Obstetrics
Preeclampsia and eclampsia require urgent pharmacological control of hypertension and seizures. Definitive treatment is delivery, but drugs stabilize the mother.
1. Antihypertensives
| Drug | Dose | Notes |
|---|---|---|
| Labetalol | 20–80 mg IV q10min | First-line |
| Methyldopa | 250–500 mg PO TDS | Safe, long-term |
| Nifedipine | 10–20 mg PO | Avoid with MgSO₄ |
| Hydralazine | 5–10 mg IV | Emergency |
Contraindicated: ACEi, ARBs, diuretics
2. Anticonvulsants: MgSO₄
Pritchard Regimen
- Loading: 4g IV + 10g IM
- Maintenance: 5g IM q4h ×24h
- Monitor: RR ≥16, reflexes, UO ≥25 mL/h
- Antidote: Calcium gluconate 10 mL IV
3. Corticosteroids (<34w)
- Betamethasone 12mg IM ×2
- For fetal lung maturity only
4. Fluid Management
- ≤80 mL/h
- Avoid overload
- NS or RL
Summary Table
| Aim | Drug | Notes |
|---|---|---|
| BP control | Labetalol, Nifedipine | Avoid ACEi |
| Seizures | MgSO₄ | 24h postpartum |
| Fetal lungs | Betamethasone | <34w |
Key Takeaways
- Labetalol = 1st-line BP
- MgSO₄ Pritchard regimen
- Monitor reflexes, RR, UO
- Calcium gluconate = antidote
- Delivery = cure
Conclusion
Pharmacology bridges the gap to safe delivery. Know the drugs, doses, and monitoring.
Preeclampsia is managed — not cured — until delivery.