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 June 2024

1: Injectable Medicines Administration Guide Medusa 31/01/2025

Therapeutic classification

Calcium channel blocker