LABETALOL (Trandate)

combined alpha and  beta receptor blocker; antihypertensive 

• decreases blood pressure (alpha blockade)
• decreases HR, contractility, myocardial oxygen requirements (beta blockade)

• Bolus:
  • 5-20 mg IV direct initially; additional doses of 40-80 mg may be given at 10 minute intervals
• Infusion:
  • 2 mg/min with the rate of infusion adjusted to supine BP
• OR
  • infusion of 0.5 - 1.0 mg/kg/hr titrated to effect

• Bolus dose:
  • 5-20 mg IV direct over a 2 minute period
  • bolus should be diluted to a concentration of 1 mg/ml
• IV Infusion:
  • 100 mg/50 mL (2 mg/ml) in D5W for initial infusion; prepared by RN as described below
  • 500 mg/250 mL (2 mg/ml) in dextrose 5%, sodium chloride 0.9% or Ringer's Lactate prepared by pharmacy

RN Bedside Preparation of Initial Labetalol Infusion

1. Remove and discard 28 ml from a 50 ml minibag of D5W. This is the volume of overflow in the minibag (8 ml) PLUS the volume of the labetalol (20 ml). This ensures consistency of drug concentration.  
2. Inject 100 mg/20 ml labetalol into the minibag to make a 2 mg/ml concentration.
3. Select labetalol from the infusion pump library and change the Volume to Be Infused (VTBI) to 50 ml.
4. Pharmacy will prepare subsequent doses as standard 500 mg/250 ml bags (2 mg/ml).

• bradycardia
• decreased contractility, cardiac output
• ventricular arrhythmias (including PVCs)
• excessive drops in BP - especially orthostatic hypotension (patients should be kept supine for 3 hours after administration)
• parasthesia (mild, transient tingling of scalp or skin)
• dyspnea, bronchospasm
• pain at injection site

• caution in left ventricular dysfunction, bronchospastic disease, pheochromocytoma (additional alpha blockade required), hepatic dysfunction

• labetalol + nitroglycerin = additive hypotensive effect
• labetalol + beta₂ agonists = decreased bronchodilation

• continuous heart rate and ECG rhythm
• blood pressure
• cardiac output if monitored
• lactate

• May be administered IV direct or by IV infusion by a nurse in Adult Critical Care
• May be titrated by a nurse in Adult Critical Care
• Administration by central venous line preferred
• Patient requires placement of an arterial line to monitor BP.
• Continuous infusions must be administered by infusion device and the pump library must be enabled.
• Should not be infused via the proximal injectate port (blue) of a pulmonary artery catheter. If this is the only available central venous line, it may be administered through the proximal injectate port but thermodilution cardiac output measurements must not be measured during infusion).