Management of Severe Hypertension During Pregnancy
Antihypertensive drugs
- Hydralazine is the most studied drug, though in the comparison with calcium channel blockers (nifedipine and isradipine) the latter have been associated with a greater reduction in the risk of persistent high blood pressure.2
- It should be noted that the analysis of the evidence related to the multiple comparisons of antihypertensive drugs for very high hypertension during pregnancy is complicated by its low quality which is due primarily to the small samples used in the trials, rare events as outcomes and variations in the adminsterred drug regimens.2
If the diastolic pressure is 110 mmHg or more, give antihypertensive drugs.
Goal is to keep the diastolic pressure between 90 mmHg and 100 mmHg to prevent cerebral hemorrhage. Avoid hypotension.
Hydralazine1 Give hydralazine 5 mg IV slowly every 5 minutes until blood pressure is lowered. Repeat hourly as needed or give hydralazine 12.5 mg IM every 2 hours as needed.
If hydralazine is not available:
Labetolol
- Give labetolol 10 mg IV1:
If response is inadequate (diastolic blood pressure remains above 110 mmHg) after 10 minutes, give labetolol 20 mg IV
- Increase dose to 40 mg and then 80 mg if satisfactory response is not obtained within 10 minutes of each dose
Calcium Channel Blockers Nifedipine 5 mg chewed and swallowed or injected into the oropharynx; may be repeated at 10-minute intervals Rectal administration of drugs1
- Give diazepam rectally when IV access is not possible. The loading dose of 20 mg is taken in a 10 ml syringe.
Remove the needle, lubricate the barrel and insert the syringe into the rectum to half its length. Discharge the contents and leave the syringe in place, holding the buttocks together for 10 minutes to prevent expulsion of the drug. Alternatively, instill the drug in the rectum through a urinary catheter. If convulsions are not controlled within 10 minutes, inject an additional 10 mg per hour or more, depending on the size of the woman and her clinical response