Table 2.

Antihypertensive drugs for severe hypertension

Drug	Dose	Comment
Labetalol	10–20 mg iv, followed by 20–80 mg every 10–30 minutes (maximum dose 300 mg) or continuous infusion at 1–2 mg/minute	First-line agent The onset of action is 1–2 minutes Avoid bronchial asthma, decompensated heart failure, heart block, bradycardia
Hydralazine	5 mg iv, followed by 5–10 mg every 20–40 minutes (maximum dose 20 mg) or continuous infusion 0.5–10 mg/hour	Onset 10–20 minutes Can cause maternal hypotension, headache
Nifedipine	10–20 mg po, repeated in 30 minutes if required, then 10–20 mg every 3–6 hours. Maximum daily dose 180 mg	Onset 5–10 minutes Reflex tachycardia, headaches Used commonly in resource-limited settings
Nicardipine	Continuous infusion 3 mg/hour; increase by 0.5 mg/hour every 20 minutes to a maximum of 15 mg/hour	Onset 10–20 minutes Tachycardia, headaches