Debate is brewing about removing injectable promethazine (Phenergan, etc) from hospital formularies...due to a new best practice from ISMP.
We're used to promethazine being one of our "go-to" antiemetics.
But the downsides keep stacking up.
IV extravasation or giving promethazine into an artery can cause tissue necrosis, which may lead to amputations.
Promethazine may lead to more sedation than other agents...and some patients may seek IV promethazine to enhance opioid-related euphoria.
Plus, promethazine, ondansetron, or metoclopramide may not work better than IV fluids alone in ED patients.
And promethazine is now pricier than ondansetron.
Consider making injectable promethazine non-formulary or restricted to when other agents or dosage forms are ineffective...or are on shortage.
If IV fluids alone don't work, lean toward ondansetron. Consider prochlorperazine for migraine...or metoclopramide for gastroparesis.
Be aware that promethazine isn't recommended to PREVENT chemo-induced nausea and vomiting (CINV)...and evidence that it prevents post-op nausea and vomiting (PONV) is limited.
Save it as a last-line TREATMENT for breakthrough CINV or refractory PONV after trying agents from classes not used for prophylaxis. For example, try olanzapine if it wasn't given for CINV prophylaxis.
In a pinch, have patients smell an isopropyl alcohol pad. It can give short-term relief, especially in PONV and ED patients.
If promethazine is needed, try PO or rectal, if able...before IM. Intramuscular administration also has risks...abscess, nerve injury, etc.
If IV can't be avoided, limit to 6.25 to 12.5 mg and give by a central line if possible. Higher doses don't seem to be more effective.
Dilute doses in at least 10 to 20 mL and give over 10 to 15 minutes. And try to limit stock to the lower 25 mg/mL concentration.
Remove injectable promethazine from order sets...and work with the IT team to create EHR guidance for converting to other antiemetics.
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- J Clin Oncol 2017;35(28):3240-61
- Medication pricing by Elsevier, accessed Jan 2018