Dihydroergotamine Intravenous for Adults

Who can administer

May be administered by registered competent doctor or nurse/midwife

Prescription must be initiated by consultant/registrar neurologist

Important information

• Must be prescribed by a consultant neurologist or Registrar neurologist
• Drug name must be written in full - no abbreviations, as experience shows that attempts to do so increase the risk of serious error
• Unlicensed medicine
• Drug interactions - several important and serious interactions (e.g. Serotonin agonists, MAOI, triptans, potent CYP3A4 inhibitors e.g. clarithromycin) see ref Use interaction checker if required

Available preparations

Dihydroergotamine (DHE) Mesylate Injection USP 1mg in 1ml (unlicensed)

Reconstitution

Already in solution for injection

Infusion fluids

Sodium chloride 0.9%

Methods of intravenous administration

Intermittent intravenous infusion (locally preferred route - off-label^{(ref 5)})

• Add required dose to 250mL infusion fluid and administer over one hour

Slow intravenous injection ^{(ref 1,2)}

• Administer required dose over 1 to 2 minutes

Dose in adults

Migraine, cluster headache ^{(ref 1)}

• Give 1mg at first sign of headache; repeat once in ONE hour if required.
• Maximum is 2mg in 24 hours and/or 6mg in 1 week (licensed in other countries)^{(ref 2)}
• There are protocols that allow for higher total weekly doses, e.g. 8mg or 11mg^{(ref 4,5)}
• Local expert opinion: max 8mg per week ^{(ref 4,5)}

Intractable migraine (status migrainosus; >72 hours) ^{(ref 2)}

• Raskin protocol (off-label dosing):
• 1. Pre-medicate with ondansetron 4mg IV every eight hours, given at least 30 minutes before each dihydroergotamine dose or alternative anti-emetic (where not contraindicated)
• 2. Give 0.5mg dihydroergotamine
• 3. Titrate to a range of 0.2 to 1mg every 8 hours for 2 to 3 days - see Table 1 below for an example of dose titration
  • Generally, a maximum daily dose of 2mg should not be exceeded, without consultant input
  • Local expert opinion: max 8mg per week ^{(ref 4,5)}

Table 1: Example of dose titration for intractable migraine
Start	Dose 1	0.5mg
8 hours later	Dose 2	0.7mg
8 hours later	Dose 3	0.9mg (max advised daily dose is 2mg see below)
8 hours later	Dose 4	1mg
All subsequent doses are 1mg, assuming the escalation to that was tolerated, and a maximum of seven more doses can be given - these additional doses may be only given on consultant's advice Generally, a maximum daily dose of 2mg should not be exceeded, without consultant input

Renal impairment ^{(ref 2)}

• CONTRAindicated in severe renal impairment

Hepatic ^{(ref 2)}

• CONTRAindicated in severe hepatic dysfunction

Monitoring

• Refer to full prescribing information ^{(ref 1,2)}. In particular monitor for signs of ergotism, serotonin syndrome and cerebral, cardiovascular or vascular ischaemia

Storage

Store below 25⁰C

References

1: SPC "Dihydroergotamine (DHE): Prescribing Information". Sterimax Inc. Oakville. USA. Date of revision Oct 2019

2. Uptodate "Dihydroergotamine: Drug Information. Lexicomp. Accessed June 2023

3. Drugs.com March 22, 2022, accessed online June 2023

4: Expert opinion Dr Thomas Monahan, Consultant Neurologist. Email on file 8th June, 2023

5: Email on file, Dr Thomas Monaghan, Consultant Neurologist, email on file 22nd June 2023

Therapeutic classification

Ergot alkaloid