A 32-year-old multiparous woman at 28 weeks of gestation is diagnosed with severe preeclampsia (BP 165/110 mmHg, proteinuria 3+, epigastric pain). She is not in labor and has no contraindications to oral therapy. Which antihypertensive is the preferred choice for immediate BP reduction while awaiting transfer to a tertiary center?

Explanation

## Antihypertensive Choice in Severe Preeclampsia (Acute BP Reduction) **Key Point:** For **acute severe hypertension in preeclampsia** (BP ≥160/110 mmHg), oral immediate-release nifedipine is a first-line recommended agent per ACOG 2022 guidelines, regardless of whether the patient is in labor. The goal is to reduce BP within 30–60 minutes to prevent maternal stroke and placental abruption. ### Clinical Context & Rationale This patient has: - Severe preeclampsia (BP 165/110 mmHg + proteinuria 3+ + epigastric pain) - **Acute severe-range BP** requiring prompt treatment (within 30–60 min per ACOG) - Oral therapy is feasible — oral immediate-release nifedipine is the appropriate choice ### ACOG 2022 Recommended Agents for Acute Severe Hypertension in Pregnancy | Drug | Route | Dose | Onset | Notes | |------|-------|------|-------|-------| | **Oral immediate-release nifedipine** | Oral | 10–20 mg, repeat q20–30 min | 10–20 min | **First-line oral agent; ACOG-recommended** | | IV labetalol | IV | 20–80 mg bolus | 5–10 min | First-line IV agent | | IV hydralazine | IV | 5–10 mg bolus | 10–20 min | Acceptable IV alternative | **High-Yield:** ACOG (2022 Hypertension in Pregnancy) explicitly recommends **oral immediate-release nifedipine** as a first-line agent for acute severe hypertension in pregnancy when IV access is not immediately available or oral therapy is preferred. It is NOT the same as sublingual nifedipine. ### Why NOT the Other Options? **Oral labetalol (option C):** - Oral labetalol has a **slow onset (2–4 hours)** and is used for **maintenance/chronic** antihypertensive therapy in pregnancy, not for acute severe-range BP reduction - ACOG does not list oral labetalol as a recommended agent for acute severe hypertension management — only **IV labetalol** is recommended for acute use - Using oral labetalol in this acute setting would delay BP control and risk maternal stroke **Intravenous hydralazine (option B):** - IV hydralazine is an acceptable agent for acute severe hypertension, but the stem specifies **oral therapy is feasible** - When oral therapy is available, oral immediate-release nifedipine is preferred over IV hydralazine due to ease of administration and comparable efficacy **Sublingual nifedipine (option D):** - Sublingual administration causes **unpredictable, precipitous BP drops** due to erratic absorption - Associated with maternal stroke, placental abruption, and fetal hypoxia - **Contraindicated** in modern obstetric practice; ACOG explicitly recommends against it - Distinct from oral immediate-release nifedipine (option A), which is swallowed and has predictable pharmacokinetics ### Clinical Pearl **Critical distinction:** Oral immediate-release nifedipine (swallowed, 10 mg capsule) ≠ sublingual nifedipine (bitten/placed under tongue). The oral route provides controlled absorption and is ACOG-endorsed for acute severe hypertension in pregnancy. The sublingual route is dangerous and obsolete. **Mnemonic for acute severe hypertension in pregnancy (ACOG 2022):** - **N**ifedipine oral IR — first-line oral - **L**abetalol IV — first-line IV - **H**ydralazine IV — acceptable IV alternative - **S**ublingual nifedipine — **NEVER** [cite: ACOG Practice Bulletin No. 222, 2020 (reaffirmed 2022) — Gestational Hypertension and Preeclampsia], [cite: ACOG Committee Opinion 767 — Emergent Therapy for Acute-Onset Severe Hypertension During Pregnancy], [cite: Harrison's Principles of Internal Medicine, 21e, Ch. 427]