B52 (medical treatment)

A B52 is an intramuscular injection containing three medications: diphenhydramine, haloperidol, and lorazepam.[1] The B stands for Benadryl (a brand name for diphenhydramine), the 5 stands for 5 milligrams of haloperidol, and the 2 stands for 2 milligrams of lorazepam.[2] This injection is used to treat agitation.[3] Haloperidol is included because it blocks dopamine receptors, which may relieve agitation.[1] Lorazepam is included because it enhances GABA inhibitory action to relieve anxiety and cause sedation.[1] Diphenhydramine is included upon the rationale that it provides sedation and reduces the risk of extrapyramidal symptoms (EPS), such as dystonia, from haloperidol.[1]

A 2021 review of B52 questioned the use of diphenhydramine in the cocktail given there was no evidence base found for its inclusion, whereas there was evidence for haloperidol and lorazepam.[2] Evidence presented in a 2022 retrospective cohort study[3] is used to argue against diphenhydramine's inclusion, based on a low risk of EPS and an association with longer stays in the emergency room.[4] The diphenhydramine component of B52 is also associated with lower oxygen levels and the use of physical restraints.[5]

See also

References

  1. 1 2 3 4 Sunshine N, Martinez J, Bazan A, Wolowich WR, Zitek T (2025). "Ketamine Versus Haloperidol/Lorazepam/Diphenhydramine Combination Treatment for Management of Acute Agitation in the Emergency Department". Open Access Emerg Med. 17: 113–120. doi:10.2147/OAEM.S486208. PMC 11840334. PMID 39981414.
  2. 1 2 Gautam M, Patel S, Sablaban I (May 2021). "Intramuscular B52". Prim Care Companion CNS Disord. 23 (3). doi:10.4088/PCC.20br02855. PMID 34015196.
  3. 1 2 Jeffers T, Darling B, Edwards C, Vadiei N (April 2022). "Efficacy of Combination Haloperidol, Lorazepam, and Diphenhydramine vs. Combination Haloperidol and Lorazepam in the Treatment of Acute Agitation: A Multicenter Retrospective Cohort Study". J Emerg Med. 62 (4): 516–523. doi:10.1016/j.jemermed.2022.01.009. PMID 35287982.
  4. ↑ Hayes, Bryan; O'Brien, Mike (April 16, 2022). "Should Diphenhydramine be included in an Acute Agitation Regimen?". Academic Life in Emergency Medicine. Retrieved April 18, 2025.
  5. ↑ Strayer RJ (February 2023). "Management of Pain and Agitation in Trauma" (PDF). Emerg Med Clin North Am. 41 (1): 117–129. doi:10.1016/j.emc.2022.09.003. PMID 36424036.
This page is issued from Wikipedia. The text is available under Creative Commons Attribution-Share Alike 4.0 unless otherwise noted. Additional terms may apply for the media files.