Parenteral Manual


Disclaimer: Official controlled document is the CHEO online copy. It is the responsibility of user to ensure that any paper copy version is the same as the online version before use.

Alternate Name(s): 
Antihypertensive agent
Original Date: 
August 2005
Revised Date: 
September 2011
  • Treatment of severe hypertension and hypertensive emergencies
Reconstitution and Stability: 
  • Available as a 5 mg/mL solution
  • Store at room temperature
  • Protect from light
  • Stable for 72 hours in compatible IV solutions at room temperature or refrigerated

- Solutions Compatible: D5W, NS, dextrose-saline combinations, ringer's solution, ringer's lactate

- Additives/Above Cassette Compatible: no information

- Y-site Compatible: amiodarone, dobutamine, esmolol, KCl, meperidine, morphine, norepinephrine, propofol

- Incompatible: amphotericin, ceftriaxone, furosemide, sodium bicarbonate


(For approved routes of administration by nursing personnel, refer to Policy for the Administration of Intravenous Medications.)

IV Direct

YES; cardiac monitoring and continuous BP monitoring  Critical care areas only
Usual dilution: 5 mg/mL
Infusion time: 2-3 minutes
Infusion rate: Maximum: 2 mg/minute

IV Intermittent Infusion


IV Continuous Infusion

YES cardiac monitoring, BP monitoring
Usual dilution:  5 mg/mL

Click here to access SDC Drug Infusion Sheet


(For neonatal dosages, refer to Neonatal IV Drug Manual.)

-  IV Direct:    

  • 0.2-1 mg/kg/dose
  • Maximum: 20 mg/dose or 2 mg/kg/dose, whichever is less

- Continuous IV infusion:

  • Initial: 0.4-1 mg/kg/hour
  • Maintenance: 0.25-1.5 mg/kg/hour
  • Maximum: 3 mg/kg/hour

- IV Direct:

  • 20 mg (may give 40-80 mg at 10 minute intervals)
  • Maximum: 300 mg total dose

- IV Continuous Infusion

  • 0.5 - 2 mg/min
Potential hazards of parenteral administration: 
  • Postural hypotension, dizziness
  • Nausea/vomiting, drowsiness, fatigue, paresthesias (especially scalp tingling)
  • Bronchospasm
  • Bradycardia
  • Somnolence, vertigo
  • Contraindicated in asthma, obstructive airway disease, greater than first degree heart block, cardiogenic shock, severe bradycardia, uncontrolled CHF, pulmonary edema
  • Caution in patients with diabetes mellitus (masks signs of hypoglycemia), impaired hepatic function (metabolized in liver) and pheochromocytoma (paradoxical hypertensive responses)
  • Additive hypotensive response may occur with halothane or isoflurane anesthesia
  • Patients should remain supine during and for up to three hours after IV administration
  • Monitor blood pressure, heart rate, pulse, EKG
  • Onset: 2-5 minutes; duration: 2-4 hours


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