Drug | Initial dose | Follow-up |
Labetalol | 20 mg IV gradually over 2 minutes. | Repeat BP measurement at 10-minute intervals:
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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. | 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:
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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. May be associated with precipitous drops in BP in some women, with associated FHR decelerations for which emergency cesarean birth may be indicated. As such, this regimen is not typically used as a first-line option and is usually reserved only for women without IV access. If used, FHR should be monitored while administering short-acting nifedipine. | Repeat BP measurement at 20-minute intervals:
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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. |