11/4/15 Update: Phentolamine is available again!
The rest of the post is un-edited, but check with your purchaser to see if you can get phentolamine now.
Another one bites the dust.
Phentolamine is no longer manufactured
Phentolamine has now made ASHP’s list of drugs no longer available.
This information is critical to communicate to emergency medicine and critical care practitioners, as the risk:benefit of peripheral vasopressor therapy changes without the availability of this extravasation antidote.
This doesn’t change my any port in a storm philosophy of peripheral vasopressor use, but it will make me advocate for the placement of a central line sooner in patients where I see peripheral vasopressor use continuing for more than a few hours.
The alternatives to phentolamine for extravasation from phenylephrine, norepinephrine, epinephrine, dopamine, and dobutamine are:
- Apply heat proximal to site of extravasation.
- Elevation of the site of extravasation.
- Topical nitroglycerin 2%, apply a 1-inch strip to the site of ischemia q8 hrs prn; monitor for hypotension.
- Dilute 1 mg terbutaline in 10 ml NS. Inject locally across symptomatic sites.
The alternatives to phentolamine for extravasation from vasopressin and methylene blue are:
- Apply heat proximal to site of extravasation.
- Elevation of the site of extravasation.
- Topical nitroglycerin 2%, apply a 1-inch strip to the site of ischemia q8 hrs prn; monitor for hypotension.
The alternatives to phentolamine for extravasation from epinephrine autoinjector are:
- Watchful waiting.
- Topical nitroglycerin 2%, apply a 1-inch strip to the site of ischemia q8 hrs prn; monitor for hypotension.
- Dilute 0.5 to 1 mg terbutaline in 1 ml NS. Inject locally across symptomatic sites (it is usually the finger).
Resources:
Excellent review of extravasation from non-cytotoxic drugs
Use of subcutaneous terbutaline to reverse peripheral ischemia
If you like this post, check out my book – A Pharmacist’s Guide to Inpatient Medical Emergencies: How to respond to code blue, rapid response calls, and other medical emergencies.
There is no clear cut evidence to support 1. elevating the extremity 2. applying heat proximal to extravasation… Actually applying heat can be more harmful depending on the drug involved especially when it may initially be difficult to establish the margins of infiltration and microinfilitration not yet visible to the eye….
I’m not aware of any RCT demonstrating heat is beneficial. Take a look at the review linked above. They discuss when to consider the application of heat/elevation of extremity in addition to pharmacotherapy options.