Hypertensive Crisis Drug Summary

Last updated: 12 December 2025
Reviewed by

ACE Inhibitor

Drug Dosage Remarks
Enalapril 1.25-5 mg by slow IV injection or infusion over at least 5 minutes repeated 6 hourly if needed
Total cumulative dose: 50 mg/day 		Adverse Reactions
  • CV effects (hypotension, angioedema); CNS effects (dizziness, fatigue, headache); Dermatologic effects (skin rashes, erythema multiforme, toxic epidermal necrolysis); Hypersensitivity reactions; Other effects (renal impairment, hyperkalemia, hyponatremia)
Special Instructions
  • Avoid in patients with history of angioedema related to previous treatment with ACE inhibitors, hereditary or idiopathic angioedema
  • Use with caution in patients with renal impairment, aortic or mitral valve or renal artery stenosis, collagen vascular disease
  • Stop using potassium-sparing diuretics or potassium supplements prior to therapy of patients with HF
  • Monitor BP, renal function and potassium levels

Anti-anginal Drug

Drug Dosage Remarks
Glyceryl trinitrate
(Nitroglycerin,
GTN, NTG) 		Initial dose: 5-25 mcg/min IV
infusion
Increase by 5 mcg/min every 3-5 minutes until some response is noted
If there is still no response at 20 mcg/min: May increase at increments of 10 mcg/min and later if required, 20 mcg/min increments can be used
Usual dose: 5-100 mcg/min IV infusion
Once a partial BP response is obtained, increases in dose increments should be decreased and time between dose increases
should be longer
Max dose: 200 mcg/min 		Adverse Reactions
  • IV administration (especially if given too rapidly): May cause CV effects (severe hypotension, retrosternal discomfort, palpitations, tachycardia); GI effects (nausea and retching, abdominal pain); CNS effects (headache, apprehension, restlessness, muscle twitching, syncope); Other effect (diaphoresis); prolonged administration has been associated with methemoglobinemia
  • Nitrate tolerance usually develops with long-term use and dosing with adequate nitrate-free interval is recommended
Special Instructions
  • Avoid in patients with severe hypotension, hypovolemia, marked anemia, HF due to obstruction or raised ICP due to head trauma or hemorrhage
  • Use with caution in patients with severe renal or hepatic dysfunction, hypothyroidism, malnutrition or hypothermia
  • Close monitoring of heart rate and BP is necessary during IV infusion
  • Do not administer to patients who have taken phosphodiesterase inhibitors within the past 24 hours
  • The plastic used for administration may absorb GTN and dosing may need to be adjusted for this

Beta-blockers

Drug Dosage Remarks
Esmolol Intra-op tachycardia and hypertension (immediate control)
Loading dose: 80 mg IV over 30 seconds, followed by 150 mcg/kg/min IV infusion, may increase to 300 mcg/kg/min, if needed
Supraventricular tachycardia and post-op tachycardia and hypertension (gradual control)
Loading dose: 500 mcg/kg IV over 1 minute
Followed by:
Maintenance infusion: 50 mcg/kg/min IV over 4 minutes
If response is inadequate within 5 minutes, titrate the maintenance infusion in increments of 50 mcg/kg/min for 4 minutes up to max of 300 mcg/kg/min or
If necessary, repeat the loading dose prior to each increase in the
maintenance infusion rate 		Adverse Reactions
  • CNS effects (fatigue, depression, dizziness, confusion, sleep disturbances, headache); CV effects (HF, heart block, coldness of extremities, hypotension); Respiratory effect (bronchospasm in susceptible patients); GI effects (nausea/vomiting, diarrhea, constipation); Metabolic effects (can produce hyper- or hypoglycemia, changes in serum cholesterol and triglycerides)
  • Esmolol: Infusion site reactions (eg inflammation and induration)
Special Instructions
  • Contraindicated in severe bradycardia, pre-existing high degree of AV block, sick sinus syndrome and decompensated HF
  • Use with caution in patients with bronchospastic diseases, renal impairment, 1st-degree heart block or depressed myocardial contractility, depression, peripheral vascular disease; patients on Insulin
  • Beta-blockers may mask the symptoms of hyperthyroidism and hypoglycemia and may aggravate psoriasis
  • Patients on long-term treatment should not discontinue abruptly; should discontinue gradually over 1-2 weeks
  • Monitor BP during administration
  • Esmolol: Use with caution in patients with hypertension associated with hypothermia
Labetalol Initial dose: 20 mg slow IV injection over
2 minutes, then 40-80 mg IV every 10 minutes until desired effect
Max dose: 300 mg
Continuous infusion: 2 mg/min IV until desired effect
Dose range: 50-200 mg
Max dose: 300 mg
Metoprolol 2.5-5 mg IV bolus over 2 minutes
May repeat every 5 minutes to
Max dose: 15 mg

Calcium Antagonists

Drug Dosage Remarks
Clevidipine Initial dose: 1-2 mg/hr IV infusion
May double infusion rate every 90 seconds until BP goal is nearly achieved, then increase by less than double every 5-10 minutes as needed
An approximately 1-2 mg/hr increase will generally produce an additional 2-4 mmHg decrease in SBP
Maintenance dose: 4-6 mg/hr IV infusion
Max dose: 21-32 mg/hr IV infusion
Max duration: 72 hours		 Adverse Reactions
  • CV effects (hypotension, reflex tachycardia); CNS effect (headache); GI effects (nausea/vomiting)
  • Less common other effects are myocardial infarction, cardiac arrest, syncope, dyspnea
Special Instructions
  • Avoid in patients with soy or egg allergies, severe aortic stenosis, with defective lipid metabolism such as pathological hyperlipidemia, lipid nephrosis, or acute pancreatitis if it is accompanied by hyperlipidemia
  • Close monitoring of heart rate and BP is necessary during IV infusion
Diltiazem 5-15 mcg/kg/min IV infusion Adverse Reactions
  • CV effects (depression of cardiac function, hypotension, worsening HF, edema, flushing, bradycardia); GI effect (constipation); CNS effects (headache, dizziness)
  • Heart rate-modulating calcium antagonists (eg Diltiazem, Verapamil): AV dissociation, AV block, bradycardia and sinus node dysfunction
Special Instructions
  • Contraindicated in patients with overt decompensated HF, marked bradycardia, sick sinus syndrome, heart block, liver failure
  • Heart rate-modulating calcium antagonists are contraindicated in patients with bradycardia, sinus node dysfunction and AV nodal block
  • Use with caution in patients with HF, complicated AMI, severe aortic stenosis, atrial fibrillation with Wolff-Parkinson-White syndrome, portal hypertension, hepatic impairment or reduced hepatic blood flow, patients with impaired renal function
  • ECG monitoring is necessary
Nicardipine Initial IV infusion (diluted to 0.1 mg/mL):
0.5-6 mcg/kg/min IV drip infusion at a rate of
0.5 mcg/kg/min until the desired BP value is reached or
5 mg/hr IV infusion, titrate by 2.5 mg/hr every 5-15 minutes to desired effect
Max dose: 15 mg/hr and reduced to 3 mg/hr
Verapamil 2.5-5 mg (1-2 ampules) as slow IV infusion

Cardiac Drug

Drug Dosage Remarks
Fenoldopam IV infusion: 0.1 mcg/kg/min;
titrated based on patient response by 0.05-0.1 mcg/kg/min increments every 15 minutes
Max dose: 1.6 mcg/kg/min
Initial lower doses (0.03-0.1 mcg/kg/min IV) may be used to help avoid reflex tachycardia 		Adverse Reactions
  • CV effects (hypotension, flushing, reflex tachycardia, ECG abnormalities have been reported); CNS effects (dizziness, headache); GI effects (nausea/vomiting); Other effects (may increase intraocular pressure, hypokalemia)
Special Instructions
  • Monitor BP, heart rate and electrolytes during therapy
  • Use with caution in patients with glaucoma, sulfite sensitivity

Diuretic

Drug Dosage Remarks
Furosemide 20-80 mg IV (with other antihypertensive agents) Adverse Reactions
  • CV effects (circulatory collapse, cardiac arrhythmias, hypotension, ischemic complications); Metabolic effects (electrolyte imbalance including hyponatremia, hypokalemia, hypochloremic alkalosis); Dermatologic effects (purpura, photosensitivity, rash, urticaria, pruritus, exfoliative dermatitis, erythema multiforme, vasculitis); Other effects (excessive sweating, fever, headache, malaise)
Special Instructions
  • Avoid in patients with hypersensitivity to sulfonamides, anuria, renal failure with azotemia and/or oliguria, hepatic coma or severe electrolyte depletion
  • Use with caution in patients with partial urinary outflow obstruction or micturition impairment, precomatose associated with hepatic cirrhosis, gout
  • Monitor BP, heart rate and electrolytes regularly

Other Antihypertensives

Drug Dosage Remarks
Clonidine Hypertensive crisis:
150-300 mcg slow IV injection over
10-15 minutes
Max dose: 750 mcg IV over 24 hours or
0.2 mcg/kg/min IV infusion at a rate not to exceed 0.5 mcg/kg/min
Max dose: 150 mcg/infusion
Hypertensive emergency:
Initially 100-200 mcg IV followed by 50-100 mcg IV hourly until BP is controlled
Max dose: 500-800 mcg 		Adverse Reactions
  • CNS effects (drowsiness, dizziness, headache, depression, anxiety, fatigue, sleep disturbances); GI effects (dry mouth, constipation, nausea, anorexia); CV effect (orthostatic hypotension); Other effects (loss of libido, urinary retention, dry itching in the eye)
Special Instructions
  • Use with caution in patients with cerebrovascular disease, ischemic heart disease, myocardial infarction, peripheral vascular disorders, depression, in patients with renal impairment
Diazoxide 1-3 mg/kg IV within 30 seconds
Repeat after 5-15 minutes if required
Max dose: 150 mg 		Adverse Reactions
  • CV effects (coronary ischemia leading to angina, cardiac arrhythmias, marked ECG changes, tachycardia, palpitations, bradycardia); CNS effects (cerebral ischemia leading to confusion, convulsions, loss of consciousness and neurological deficit); Other effects (impaired renal function, vasodilatation symptoms, burning sensation in the vein used for injection)
Special Instructions
  • Use with caution in patients with renal impairment, risk factors for pulmonary hypertension, impaired cardiac or cerebral circulation, aortic coarctation, arteriovenous (AV) shunt, HF or other cardiac disorders in which increase in cardiac output could be detrimental
  • Monitor BP, glucose levels, white cell and platelet count regularly in prolonged therapy
Hydralazine 5-10 mg slow IV injection
May repeat after 20-30 minutes, if needed
or
10-20 mg IV 4-6 hourly as needed
Total cumulative dose: 200 mg/day
or
Initial dose:
200-300 mcg/min continuous IV
infusion
Maintenance dose:
50-150 mcg/min
or
20-40 mg IV push or IM injection then repeat if necessary 		Adverse Reactions
  • CV effects (tachycardia, palpitations, angina, flushing, postural hypotension, fluid retention, edema); GI effects (anorexia, nausea/vomiting, or diarrhea, weight gain); Other effects (headache, dizziness, nasal congestion, tremor, muscle cramps, lacrimation)
  • Less common: Pyridoxine depletion with resulting peripheral neuropathy; Hematologic effects (blood dyscrasia, hemolytic anemia); Hepatic effect (hepatotoxicity); GU effects (difficulty in urinating, glomerulonephritis); CNS effects (depression, anxiety); GI effects (paralytic ileus, constipation); Hypersensitivity reactions
Special Instructions
  • Avoid in patients with severe tachycardia, HF with high cardiac output, dissecting aortic aneurysm, cor pulmonale, or myocardial insufficiency due to mechanical obstruction, idiopathic systemic lupus erythematosus and related disorders
  • Use with caution in patients with ischemic heart disease, patients with recent myocardial infarction, patients with heart failure, impaired renal or hepatic function, cerebrovascular accidents
Phentolamine Prevention or control of hypertensive episodes in patient with pheochromocytoma:
Preoperative reduction
of BP: 2-5 mg IV/IM 1-2 hours before surgery, repeat if necessary
Intraoperatively, 2-5 mg IV injection
or
5 mg IV every 10 minutes as needed
Usual dose: 5-15 mg IV
Total cumulative dose: 50 mg/day 		Adverse Reactions
  • CV effects (acute and prolonged hypotensive episodes, tachycardia, cardiac arrhythmias, flushing); CNS effects (weakness, dizziness); GI effects (nausea/vomiting, diarrhea); Other effect (nasal stuffiness)
Special Instructions
  • Avoid in patients with myocardial infarction, coronary artery disease
  • Use with caution in patients with history of CV disease, peptic ulcer, gastritis
Sodium
nitroprusside
(Na nitroprusside,
Nitroprusside) 		Initial dose: 0.3-1.5 mcg/kg/min IV infusion
Gradually titrate up by 0.5 mcg/kg/min every 5 minutes until BP control is achieved
Usual dose: 0.5-6 mcg/kg/min
Max dose: 8 mcg/kg/min or
10 mcg/kg/min for 10 minutes		 Adverse Reactions
  • Adverse effects are typically either due to hypotensive effects or from excessive cyanide accumulation
  • These effects may be reduced with a decrease in infusion rate: GI effects (nausea/vomiting, abdominal pain); CNS effects (apprehension, headache, dizziness, restlessness); CV effects (retrosternal discomfort, palpitations); Other effects (perspiration, muscle twitching)
  • Excessive cyanide may result in tachycardia, sweating, hyperventilation, arrhythmias and metabolic acidosis; methemoglobinemia may also occur
  • Thiocyanate may cause tinnitus, miosis, hyperreflexia, confusion, hallucinations and convulsions have been reported
Special Instructions
  • BP and acid base balance should be monitored closely
  • Avoid extravasation
  • Avoid in compensatory hypertension
  • Use with caution or not at all in hepatic impairment and in patients with low plasma cobalamin concentration or Leber’s optic atrophy
  • Use with caution in patients with hypothyroidism, impaired cerebrovascular circulation
  • If continued for >72 hours, plasma concentration of cyanide should be monitored
  • When discontinuing, reduce dose slowly
Urapidil Hypertensive emergency: 25 mg bolus IV injection, repeated if necessary after 5 minutes at maintenance dose.
If BP reduction is insufficient, repeat 25 mg IV injection in 20 seconds
Repeat if necessary after 5 minutes at maintenance dose. If response is still inadequate after 5 minutes, give 50 mg bolus IV injection. Once BP is sufficiently reduced after 5 minutes, treat at maintenance dose
Maintenance dose: 9-30 mg/hr IV infusion or by syringe pump
Severe hypertension during and/or after surgery: 25 mg IV injection over 20 seconds, repeated if necessary after 2 minutes at maintenance dose. If BP reduction is insufficient after 5 minutes, repeat 25 mg IV injection over 20 seconds
Repeat if necessary after 2 minutes at maintenance dose. If response is still inadequate after 5 minutes, give 50 mg IV injection over 20 seconds. Once BP is sufficiently reduced after 2 minutes, treat at maintenance dose
Maintenance dose: 60-180 mg/hr IV infusion or by syringe pump 		Adverse Reactions
  • GI effects (nausea/vomiting); CV effects (tachycardia, palpitations, bradycardia, tightness in chest, dyspnea); CNS effects (headache, agitation, dizziness); Other effects (thrombocytopenia, pruritus, erythema, rashes, nasal congestion, asthenia, sweating)
Special Instructions
  • In hypertensive emergency, dose should be adjusted such that the drop in BP does not exceed 25% of the initial level in the hour following the initiation of treatment by injection as too sudden fall in BP may result in myocardial, cerebral or renal ischemia
  • Avoid in patients with aortic isthmus stenosis or AV shunt (except AV shunts for hemodialyses)
  • Use with caution in the elderly, in renal and severe hepatic insufficiency, in patients with bradycardia and cardiac arrest
  • Monitoring of hemodynamic changes may be needed in patients with renal impairment

Disclaimer

All dosage recommendations are for non-pregnant and non-breastfeeding women, and non-elderly adults with normal renal and hepatic function unless otherwise stated.  
Not all products are available or approved for above use in all countries.  
Products listed in the Drug Summary are based on indications stated in the locally approved product monographs.   
Please refer to local product monographs in Related MIMS Drugs for country-specific prescribing information

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