SX:
diastolic >130 mmHg, malaise, weakness, fatigue, weight loss, headache, altered mental status, visual symptoms, focal deficits, seizures, come, somnolence, nausea & vamiting, papilledema (+/- hemorrhages & exudates), evidence of renal function deterioration (azotemia, proteinuria, hematuria) , evidence of neurologic dysfunction, compromised cardiopulmonary function such as angina, MI, CHF, etc.

RX:
Initial Goal is to reduce mean arterial pressure by no more than 25% within minutes to 2 hours, then to move further downward toward 160/100 mmHg within 2-6 hours.

Furosemide (Lasix) 40-80 mg IV   if indicated.

Na Nitroprusside (Nipride) start with 0.3- 0.5 ug/kg/min, then 1-3 ug/kg/min IV (max:<10 ug/kg/min) (50 mg in 250 ml D5W)

• Onset: 0.5- 1 min
• Duration: 1 5 min
• Adverse effects: hypotension, N&V, apprehension, cyanide (thiocyanate level>10 mg/dl is toxic; >20 mg/dl may be fatal) toxicity convulsion, twitching, psychosis, dizziness, etc.

Diazoxide (Hyperstat) 300 mg IV bolus (*Not used as much in recent years)

• Onset: 1-2 min
• Duration: 4-12 h
• Adverse effects: nausea, flushing, Na retention, hyperglycemia, tachycardia, palpitations, chest pains, sedation & somnolence

Hydralazine (Apresoline) 10- 50 mg IV or IM

• Onset: 10-30 min
• Duration: 3- 8 h
• Adverse effects: tachycardia, flushing, headache, vomiting, contraindicated in angina or aortic dissection

Nifidipine (Procardia) 10- 20 mg PO for asymptomatic pts.  (*Sublingual is not recommended by JNC VI recently)

• Onset: <30 min
• Duration: 4 -5 h
• Adverse effects: postural hypotension, flushing

Nicardipine  (Cardene) 5-15 mg/h IV

• Onset: 5-10 min
• Duration: 1-4 h
• Adverse effects: tachycardia, headache, flushing, local phlebitis

Labetalol (Trandate) 20 mg IV, then 20- 80 mg q10 min prn, or start with 0.5 mg/min, then 1 2 mg/min (may be up to 4 mg/min) IV infusion up to 300 mg/d max.

• Onset: <5-10 min
• Duration: 3-6 h
• Adverse effects: hypotension,heart block, dizziness, N&V, scalp tingling, throat burning.  

Esmolol (Brevibloc) 250-500 mcg/kg/min for 1 min, then 50-100 mcg/kg/min for 4 min, may repeat sequence.

• Onset: 1-2 min
• Duration: 10-20 min
• Adverse effects: hypotension, nausea

Nitroglycerin IV infusion start 5-10 ug/min then may be up to >200 ug/min prn esp. in pts where Na nitroprusside is relatively contraindicated & pts with ischemic heart disease, impaired renal or hepatic function.

• Onset: immediate
• Duration:1 3 min
• Adverse effects: headache, vomiting, methemoglobinemia

Phentolamine (Regitine) 5-15 mg IV

• Onset: 1-2 min
• Duration: 3-10 min
• Adverse effects: tachycardia, flushing, headache

Clonidine (Catapres) 0.2 mg PO, followed by 0.1 mg/hr to total of 0.7 mg or reduction in diastolic BP of 20 mmHg or more.

• Onset:
• Duration:
• Adverse effects: drowsiness, bradycardia

Captopril (Capoten) 25 mg PO

References:
J Critical Illness 1990/09;5:973. Devault GA (U of Utah)
Patient Care 2/15/1999; 129 - Consultants: J.Stephen Bohan, Norman M. Kaplan, Venkata S. Ram