Verapamil Intravenous for Adults

Who can administer

Administration RESTRICTED - see Appendix 1

Important information

• See 'Monitoring requirements' below

Available preparations

Isoptin 5mg per 2ml ampoule

Reconstitution

Already in solution

Draw up using a 5 micron filter needle

Infusion fluids

Sodium chloride 0.9% or Glucose 5%

Methods of intravenous administration

Slow intravenous injection (preferred method)

• Administer required dose over 2 minutes (3 minutes in elderly patients) (ref 1)

Continuous intravenous infusion (ref 1)

• Add required dose to a suitable volume of infusion fluid
• Administer as per 'Dose' below

Dose in adults

Usual dose

• Give 5mg initially, as a slow intravenous injection
• If the therapeutic response is inadequate, a further 5mg may be injected after five or ten minutes
• If required an infusion of 5 to 10mg per hour can be given, up to a usual maximum of 100mg/day to maintain the therapeutic effect
• If there is any signs of tachycardia-induced heart failure, digitalisation is necessary before administration of verapamil intravenously

Hypertensive crisis

• Initial treatment: 0.05 to 0.1mg/kg/hour (= 3.5 to 7mg/hour for a 70kg patient)
• If the effect is insufficient, increase the dose at thirty to sixty minute intervals until twice the dose or more is reached
• Average total dose is up to 1.5mg/kg/day (105mg daily for a 70kg patient)

Hepatic impairment

• The half-life of verapamil is prolonged in patients with impaired liver function owing to lower oral clearance and a higher volume of distribution. When given intravenously, verapamil has been shown to be rapidly metabolised

Monitoring

• Continuous ECG and blood pressure monitoring required

Storage

Store below 25⁰C

References

SPC December 2021

1: Injectable Medicines Administration Guide Medusa 14th December 2021

Therapeutic classification

Calcium channel blocker