Labetalol Intravenous for Adults

Who can administer

Administration RESTRICTED - see Appendix 1

Important information

• Should always be administered while patient is in the supine or left lateral position
• Raising the patient into the upright position within three hours of intravenous labetalol administration should be avoided, since excessive postural hypotension may occur
• Q pulse document -'WAC Group Guideline and Pathway on the Management of Hypertensive Disorders in Pregnancy'(CLN-LW-0032) should be consulted for most up to date information on the use of labetalol in this indication ^{(ref 1)}
• For Y-site compatibility see below

Available preparations

Trandate 100mg per 20ml ampoule

Labetalol 100mg per 20ml ampoule

Reconstitution

Already in solution

Draw up using a 5 micron filter needle

Infusion fluids

Glucose 5% (or see further information)

Methods of intravenous administration

Continuous intravenous infusion (administer using an electronically controlled infusion device)

• Dilute 200mg (40ml) injection solution with 160ml infusion fluid (1mg per ml)
• Ideally administer via central line. If essential, can be given via a large peripheral vein ^{(ref 4)}
• Fluid restriction: use undiluted ^{(ref 2,3)} via central line ^{(ref 2)} - unlicensed, anecdotal evidence base

Bolus intravenous injection (emergency situations such as hypertensive encephalopathy)

• Administer each 50mg over at least one minute (over five minutes if used in severe hypertension in pregnancy ^{(ref 1)})
• May be repeated every five minutes to a usual maximum total dose of 200mg (may be repeated at 10 minute intervals if used in severe hypertension in pregnancy ^{(ref 1)})
• Administer via central line or large peripheral vein ^{(ref 4)}

Dose in adults

Hypertension of pregnancy

• Commence an intravenous infusion at a rate of 20mg per hour
• This dose may be doubled every thirty minutes until a satisfactory reduction in blood pressure has been obtained or a dose of 160mg per hour is reached
• Occasionally higher doses may be necessary

Hypertensive episodes following acute myocardial infarction

• Commence an intravenous infusion at 15mg per hour
• Gradually increase to a maximum of 120mg per hour, depending on blood pressure control

In hypertension due to other causes

• Commence an intravenous infusion at about 2mg per minute, until a satisfactory response is obtained
• The infusion should then be stopped
• The effective dose is usually in the range of 50 to 200mg, depending on the severity of the hypertension
• For most patients it is unnecessary to administer more than 200mg, but larger doses may be required, especially in patients with phaechromocytoma

Acute Stroke

• See Local guidelines - Acute Stroke Thrombolysis and thrombectomy Integrated Care Pathway

Monitoring

• Monitor blood pressure, heart rate and respiratory function throughout the infusion
• Monitor LFTs as severe hepatocellular damage has been reported
• Monitor infusion site every 30 minutes ^{(ref 3)}

Further information

• Labetalol may also be diluted in glucose infusion fluids containing sodium chloride e.g. Sodium chloride 0.18%/Glucose 4%, or in Sodium chloride 0.9% ^{(ref 4)}

Storage

Store below 25⁰C

References

SPC March 2023

1'WAC Group Guideline and Pathway on the Management of Hypertensive Disorders in Pregnancy -Drug Treatment guidelines for severe hypertension in pregnancy"(CLN-LW-0032) Q-Pulse document

2. "Critical Care Group: Minimum infusion volumes for fluid restricted critically ill patients: 4th edition 2012 UKCPA

3. Injectable Drugs Guide accessed via Medicinescomplete 07/03/2024

4: Medusa IV guides, downloaded 07/03/2024

5. BNF accessed online 07/03/2024

Therapeutic classification

Beta adrenoreceptor blocking agent with alpha blocking activity