II. Indications

  1. Blood Pressure exceeds 160/110 mmHg (Severe Preeclampsia) for more than 15 minutes

III. Protocol: Initial program (Titrate to BP <160/110 mmHg)

  1. Precautions
    1. Start within one hour of identifying BP >160/110 mmHg (persistent >15 min)
  2. Labetolol (Normodyne)
    1. Safe and offers benefits over Hydralazine
      1. Lower Incidence of maternal Hypotension
      2. Lower Incidence of ceserean delivery
    2. Start: 20 mg IV bolus every 10-20 minutes prn
    3. Some recommend more aggressive management
      1. Start at Labetolol 20 mg IV for first dose as above
      2. If insufficient effect after 10 min: 40 mg IV
      3. If insufficient effect after 10 min: 80 mg IV
      4. If insufficient effect after 10 min: 80 mg IV
      5. Switch to other drug if no effect with 220 mg total
    4. Oral dosing is safe and effective
      1. Labetalol 100 mg orally twice to three times daily and titrate
      2. May be dosed up to a very high maximum (2400 mg/day)
    5. Contraindications
      1. Avoid in Asthma
      2. Avoid in Congestive Heart Failure
  3. Nifedipine XL (Procardia XL)
    1. More rapid control of Hypertension than Labetolol
    2. Avoid short-acting Nifedipine as well as other Calcium Channel Blockers
    3. Could it block Calcium as Magnesium Sulfate antidote?
    4. Start: 10 mg PO every 20-30 minutes prn (up to 3 doses)
      1. Second and third dose may be for Nifedipine 20 mg
      2. If not sufficient control after 3 doses, give switch to Labetolol IV
  4. Hydralazine (Apresazide)
    1. Was considered drug of choice due to 30 years of PIH use
      1. Now considered third line (after Labetolol and Nifedipine) due to adverse effects
    2. Adverse effects
      1. Fetal Tachycardia
      2. Maternal Headache or Palpitations
    3. Start: 5 mg IV or 10 mg IM every 20 minutes prn
    4. Maintenance: 5 mg IV or 10 mg IM every 3 hours prn
    5. Switch to Labetolol IV if still uncontrolled
      1. After 20 mg IV total or
      2. After 30 mg IM total
  5. Second-Line, Refractory Severe Hypertension (not recommended by ACOG for first-line use)
    1. Nicardipine
      1. ACOG considers as second-line agent for Severe Hypertension refractory to agents listed above
      2. (2017) Obstet Gynecol 129(4):e90-5 +PMID: 28333820 [PubMed]
      3. Bijvank (2010) Obstet Gynecol Surv 65(5):341-7 +PMID:20591204 [PubMed]

IV. Management: Maintanence medications (titrate to keep BP <160/110)

  1. Methyldopa 250-500 mg orally 2-4 times daily
  2. Labetalol 100-400 mg orally twice daily
  3. Hydralazine 10-50 mg orally four times daily
  4. Nifedipine ER or XL 30-90 mg daily

V. Management: Postpartum

  1. Anticipate increased Blood Pressure in the first few days after delivery (due to fluid redistribution)
  2. Antihypertensive indications
    1. Postpartum for BP >150/100 mmHg on at least 2 readings 4 hours apart
    2. Start Antihypertensives emergently if BP >160/110 mmHg
  3. Hypertension remits by 6-12 weeks postpartum
  4. Recheck 7-10 days after discharge

VI. Precautions

  1. Pregnancy Related Hypertension is a significant risk for Cerebrovascular Accident
    1. See Preeclampsia Prevention
    2. See Cerebrovascular Accident Risk in Women
    3. Manage Blood Pressure appropriately with goal BP <160/110 mmHg
      1. CVA in Severe Preeclampsia typically occurs with BP >160/110 mmHg
      2. Martin (2005) Obstet Gynecol 105(2): 246-54 [PubMed]
  2. Antihypertensives are not indicated for mild to moderate Chronic Hypertension in Pregnancy
    1. Treatment of BP <150/100 does not reduce risk to fetus or prevent Preeclampsia
    2. Aggressive lowering of Blood Pressure may result in adverse fetal outcomes
    3. Severe chronic Hypertension (consistently >150-180/100-110) should be treated
    4. (2001) Obstet Gynecol 98(1 suppl): 177-85 [PubMed]
  3. Avoid contraindicated Antihypertensives
    1. Avoid ACE Inhibitors, ARBs, Aliskiren or Tekturna (due to neonatal Renal Failure, Teratogenic, IUGR)
    2. Avoid spironlactone, Eplerenone
    3. Avoid Atenolol (due to IUGR risk)
      1. Other Beta Blockers (other than Labetalol) are also generally avoided
    4. Avoid Thiazide Diuretics (maternal fluid depletion, Hypokalemia)
      1. Although Thiazide Diuretics may be continued if on chronically prior to pregnancy

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