Phenylephrine Intravenous for Adults

Who can administer

Administration RESTRICTED - see Appendix 1

Available preparations

Phenylephrine hydrochloride Injection 100micrograms/mL solution for injection/infusion (2mg/20mL)

Phenylephrine hydrochloride pre-filled syringe 50microgram/mL (500micrograms in 10mL)

Reconstitution

Already in solution

Infusion fluids

Not required- already in solution

Methods of intravenous administration

See under 'Dose' for which route of administration to use

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

• Draw up 3 x 2mg/20mL vials using a 50ml syringe (which has graduations marked up to 60ml)
• This solution contains 100micrograms/ml
• Titrate dose to response
• When an intravenous infusion is discontinued, slow the rate gradually - do not stop it abruptly ^{(ref 1)}

Slow intravenous injection^{(ref 1)}

• Administer required dose over 3 to 5 minutes

Dose in adults

Hypotension - by continuous intravenous infusion - ICU, CCU, or other critical care areas only
Initial dose	Initially 25 to 50micrograms/minute (0.25 to 0.5mL/minute using a 100microgram/mL solution)
Subsequently	25 to 100microgram/minute (0.25 to 1mL/minute using a 100microgram/mL solution), adjusted according to response. This corresponds to 15 to 60ml/hour
Note: there are references to higher doses in the literature e.g.BNF

Hypotension - by slow intravenous injection

• Dose range 50 to 100micrograms repeated as necessary after at least 15 minutes ^{(ref 2)}
• Intravenous injections are effective for up to about 20 minutes ^{(ref 2)}

Monitoring

• Monitor for extravasation
• Monitor blood pressure, heart rate
• Monitor for paraesthesia in the extremities

Further information

• Can cause extravasation

Storage

Store below 25⁰C

References

Phenylephrine (Aguettant) SPC  27/06/2024
1: Injectable Medicines Administration Guide Medusa- downloaded March 2025

2: Martindale, accessed online via medicinescomplete March 2025
 

Therapeutic classification

Sympathomimetic vasoconstrictor