Drug | Initial dose | Follow-up |
Labetalol | 20 mg IV gradually over 2 minutes. | Repeat BP measurement at 10-minute intervals:
Cumulative maximum dose is 300 mg. If target BP is not achieved, switch to another class of agent. Hold dose if heart rate <60 beats per minute. |
A continuous IV infusion of 1 to 2 mg/minute can be used instead of intermittent therapy or started after 20 mg IV dose. Requires use of programmable infusion pump and continuous noninvasive monitoring of blood pressure and heart rate (reduce/discontinue infusion if heart rate <60 beats per minute). | Adjust dose within this range to achieve target blood pressure. Cumulative maximum dose is 300 mg. If target BP is not achieved, switch to another class of agent. | |
Hydralazine | 5 mg IV gradually over 1 to 2 minutes.* Adequate reduction of blood pressure is less predictable than with IV labetalol. | Repeat BP measurement at 20-minute intervals:
Cumulative maximum dose is 20 to 30 mg per treatment event. If target BP is not achieved, switch to another class of agent. |
Nicardipine (parenteral) | The initial dose is 5 mg/hour IV by continuous infusion titrated up to 15 mg/hour to achieve target BP 130 to 150/80 to 100 mmHg. The effect of dose titrations may not be observed for 5 to 15 minutes; rapid titration should be avoided to minimize risk of overshooting dose. Requires use of a programmable infusion pump and continuous noninvasive monitoring of blood pressure and heart rate. | Adjust dose within this range to achieve target BP. |
Nifedipine immediate release* | 10 mg orally. | Repeat BP measurement at 20-minute intervals:
If target BP is not achieved, switch to another class of agent. |
Nifedipine extended release | 30 mg orally. | If target BP is not achieved in 1 to 2 hours, another dose can be administered. If target BP is not achieved, switch to another class of agent. |
IV: intravenous; BP: blood pressure; FHR: fetal heart rate.
* We caution against use of immediate-release oral nifedipine, although some obstetric guidelines have endorsed its use as a first-line option for emergency treatment of acute, severe hypertension in pregnancy or postpartum (other options were labetalol and hydralazine), particularly when IV access is not in place. In most cases, use of immediate-release oral nifedipine will be safe and well tolerated; however, there is a risk of an acute, precipitous fall in blood pressure, which may result in a reduction in uteroplacental perfusion. The immediate-release preparations are also associated with a higher incidence of headache and tachycardia. In nonpregnant adults, the package insert states that "nifedipine capsules should not be used for the acute reduction of blood pressure."Do you want to add Medilib to your home screen?