Stability of compounded IV Benadryl


I’ve been working on the IV Benadryl shortage from a different angle and I’m starting to see results. Currently, compounded IV Benadryl is considered a high risk sterile compound because it’s prepared from a non sterile solution (edit: I initially wrote non sterile solution here by mistake). Board of Pharmacy/FDA guidelines state that in the absence of other evidence on day supply, compounded IV Benadryl is good for three days in the refrigerator. They also state that freezing breaks the molecule, rendering it much less effective. I found data that demonstrates that both of these things are false. Compounded IV Benadryl CAN be frozen without affecting molecular stability. There’s also data demonstrating that compounded IV Benadryl is stable much longer than three days both at room temperature and refrigerated. This is without preservative. Just diphenhydramine and water.

Pharmacists can use this data to inform day supply at their discretion. If they decide to do this, patients can pick up large supplies with much less labor and cost to pharmacies.

I would urge patients who are unstable without this medication to contact a local sterile compounding pharmacy. In some places, large hospitals will sterile compound for established outpatients, but this is very location specific.

I know this is a scary and stressful time for many of us. I want to be clear that patients who require this medication are not at fault for its shortage. There are all kinds of process controls to prevent critical shortage of ubiquitous, life saving medications. Manufacturers, distributors, and pharmacies are ALL required to track usage to allow for increased production runs if needed. Hundreds of meds are used off label and production is increased when usage is properly reported. So if you’re barking up this tree, stop barking.

There are multiple factors contributing to the shortage, including shortage of FDA approved sterile diluents like saline; the fact that some manufacturers buy their IV Benadryl premade from another manufacturer and just relabel it; manufacturing sites closing for reasons including natural disaster and acquisition by other pharma groups; and communication issues from literally every agency and organization involved in the shortage and public notification. It is so, so complex. I would love to work with an investigative journalist to tell this story once the emergency is resolved. I do not release information I cannot prove and that is not the best use of my time right now. There will be a reckoning once people are safe.

Fresenius released a small lot of IV Benadryl on Monday. Most of this lot will be used to replenish institutions and emergency services providers before there is enough to distribute to patients. The fact that even a small amount is available is a good sign.

There is a rumor flying around that IV Benadryl is not going to be made anymore. I have worked in this industry for fifteen years, have contacts at the FDA and the CDC, and spent a lot of time talking to Global Program Management for this med for US licensed distributors. I have no reason to believe IV Benadryl won’t be made again. I believe that when the shortage resolves, patients will have ready access to this medication. If I learn anything that contradicts that, I will let people know.

This will end. We are getting through this. Okay? Okay. Courage.



Link to data on stability of IV Benadryl