By Joe DiStefano, RPh

There is a national shortage of diphenhydramine (DPH) injection due to manufacturer delays. One company estimates a release date in 2019. Although other manufacturers have sooner release dates, dates frequently change during shortages and we do not expect normal supply soon.

As a result, NuFACTOR has reviewed UpToDate.com, an evidence-based, physician-authored clinical decision support resource, owned by Wolters Kluwer, a global leader in information services and trusted resource for health care professionals. Based on this review, effective immediately, NuFACTOR anaphylaxis kits for new patients receiving IV medications (or upon refill for existing patients) will not include parenteral DPH. NuFACTOR current inventory of DPH will be reserved for those patients requiring pre-medication.

UpToDate concludes the treatment of anaphylaxis centers quick action and administration of epinephrine.
Management includes:

• Removal of the inciting cause, if possible (e.g., stop infusion of a suspect medication).
• Epinephrine administration.
• Call 911 for help.
• Placement of the patient in the supine position with the lower extremities elevated, unless there is prominent upper airway swelling prompting the patient to remain upright (and often leaning forward). If the patient is vomiting, placement of the patient semi-recumbent with lower extremities elevated may be preferable. Place pregnant patients on their left side.
• Supplemental oxygen (not usually provided in the home setting).
• Volume resuscitation with IV fluids (also in short supply; not usually provided in the home setting).

UpToDate also states anti-histamines relieve itching and urticaria, and their use in anaphylaxis is extrapolated from the studies of urticaria. A systematic review of the literature failed to retrieve any randomized-controlled trials that support the use of H1 antihistamines (e.g., DPH) in anaphylaxis. These medications do not relieve upper or lower airway obstruction, hypotension or shock.

Note the NuFACTOR anaphylaxis kit already contains oral DPH and is used for the treatment of mild reactions such as itching, rash, nausea and vomiting and hives.

If you have any questions, please contact a NuFACTOR pharmacist or nurse at (800) 323-6832.