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Pharmacy Phriday #6: Tik Tok Benadryl Challenge and Diphenhydramine Toxicity

Emergency Medical Minute

Release Date: 01/01/2021

Podcast 670: Operation Tat-Type show art Podcast 670: Operation Tat-Type

Emergency Medical Minute

Contributor:  Dave Rosenberg, MD Educational Pearls: In 1951, Operation Tat-Type began tattooing adults with their blood type in an effort to prepare for rapid transfusions in the time of the Cold War and the Korean War School children in northern Indiana and areas in Utah were tattooed with their blood type beginning in 1952 under the same operation Based on tattoos given to SS officers during WWII This wasn't to identify who needed what blood but rather to identify who could give what blood in the event of a massive attack References Wolf EK, Laumann AE. The use of blood-type tattoos...

Podcast 669: VTach Storm show art Podcast 669: VTach Storm

Emergency Medical Minute

Contributor:  Gretchen Hinson, MD Educational Pearls: Three episodes of ventricular tachycardia within 24 hours or two episodes back-to-back Treat with IV amiodarone and IV beta-blockers initially as well as IV lidocaine Correct underlying causes:  IV magnesium for QT prolongation Replete potassium in hypokalemia Urgent revascularization in ischemia For refractory vtach, urgent radiofrequency ablation or stellate ganglion block can be done Last resort is placing on the patient on ECMO References Muser D, Santangeli P, Liang JJ. Management of ventricular tachycardia storm in...

Podcast 668: Opioid-Induced Hyperalgesia show art Podcast 668: Opioid-Induced Hyperalgesia

Emergency Medical Minute

Contributor: Donald Stader, MD Educational Pearls: Opioids target kappa and NMDA receptors that can lead to central nervous system sensitization and therefore increased pain For patients with opioid-induced hyperalgesia (OIH), oral ketamine (25-50 mg) can be used to treat their pain as it targets the NMDA receptor Other treatments is IV magnesium, NSAIDs, tylenol, and clonidine Buprenorphine and methadone are options for chronic pain management in the setting of OIH References Lee M, Silverman SM, Hansen H, Patel VB, Manchikanti L. A comprehensive review of opioid-induced hyperalgesia. Pain...

Podcast 667: Lactated Ringers for DKA show art Podcast 667: Lactated Ringers for DKA

Emergency Medical Minute

Contributor:  Aaron Lessen, MD Educational Pearls: Recent study looked at whether lactated ringers might be a better choice for fluid resuscitation in patients with DKA compared to normal saline Normal saline can cause a hyperchloremic metabolic acidosis Time to resolution of acidosis was 4 hours less with lactated ringers compared to normal saline Time on an insulin drip decreased by about 4 hours with lactated ringers compared to normal saline LR might be a better choice for fluid resuscitation in patients with DKA References Self WH, Evans CS, Jenkins CA, et al. Clinical Effects of...

Podcast 666: Pain Management & Patient Perspective    show art Podcast 666: Pain Management & Patient Perspective

Emergency Medical Minute

Contributor:  Jared Scott, MD Educational Pearls: About ½ of the patients in the ED present with some form of pain One study looked at patients presenting in pain and followed up two days after discharge to determine if their pain was addressed, asking if the patient received anything for pain and if the patient refused pain medication Non-analgesic pain management: About 30% discordance between patient reports and documentation Conventional analgesic pain management: About 15% discordance between patient reports and documentation References Taylor DM, Valentine S, Majer J, Grant N....

Podcast 665: Allergic Reactions after COVID Vaccinations show art Podcast 665: Allergic Reactions after COVID Vaccinations

Emergency Medical Minute

Contributor:  Peter Bakes, MD Educational Pearls: Incidence 2.5-10 per million people occurring primarily in those with environmental allergens Typically occurs with mRNA vaccines in lipid nanoparticles (Moderna/Pfizer) rather than the adenovirus vaccine (J&J) Recommendation is to forego 2nd dose of the mRNA vaccine and instead get the adenovirus vaccine after weighing the risks and benefits References Kounis NG, Koniari I, de Gregorio C, Velissaris D, Petalas K, Brinia A, Assimakopoulos SF, Gogos C, Kouni SN, Kounis GN, Calogiuri G, Hung MY. Allergic Reactions to Current Available...

Podcast 664: Rabies Prophylaxis show art Podcast 664: Rabies Prophylaxis

Emergency Medical Minute

Contributor:  Jared Scott, MD Educational Pearls: 1-3 cases of rabies per year in US with 55,000 people per year receiving rabies prophylaxis 90% of rabies cases come from wildlife, most commonly by racoons, bats, foxes, and skunks Because of rabies prophylaxis, domesticated pets almost never have rabies in the United States Rabies is typical transmitted via a bite, but direct contact with saliva or brain tissue on an open wound can transmit the virus Some people exposed to rabies from bats will never report a bite References Kessels J, Tarantola A, Salahuddin N, Blumberg L, Knopf L....

Podcast 663:  Down Syndrome show art Podcast 663:  Down Syndrome

Emergency Medical Minute

Contributor:  Alicia Oberle, MD Educational Pearls: Down Syndrome with Trisomy 21 have three copies of chromosome 21 Current birth rates are around 1 in 700 births  Average life span 25 years in 1980, today the average life span is 60 years of age Patients with Down syndrome require additional therapies in the first 3 years due to developmental delays They also have increased risk for childhood leukemias, seizures, hypothyroidism, celiac disease, and early-onset Alzheimers Half have a cardiac defect requiring surgery at birth References Tsou AY, Bulova P, Capone G, et al. Medical...

UnfilterED #13: Dr. Nadia Tremonti show art UnfilterED #13: Dr. Nadia Tremonti

Emergency Medical Minute

This week’s episode features a fascinating conversation with Dr. Nadia Tremonti, medical director for the pediatric palliative care program at Children’s Hospital of Michigan in Detroit. Dr. Tremonti was the featured physician in an independent short film Palliative and subsequent New York Times shorter excerpt Dying in your Mother’s Arms that explore her work with terminally ill pediatric patients. From conversations of religion’s role in processing disease to the physician’s role in alleviating suffering for patients and their families, Nick and Nadia explore the existential ground...

Podcast 662: Droperidol for Sedation show art Podcast 662: Droperidol for Sedation

Emergency Medical Minute

Contributor:  Aaron Lessen, MD Educational Pearls: Droperidol for sedation in agitated patients in the emergency department was studied compared to ziprasidone (Geodon) and lorazepam (Ativan) Double-blinded RCT showed droperidol was 65% effective to get patients to a good level of sedation in 15 minutes compared to ativan and geodon which were 25-35% effective Droperidol had less respiratory depression and prolongation of the QT compared to Ativan and Geodon References Martel ML, Driver BE, Miner JR, Biros MH, Cole JB. Randomized Double-blind Trial of Intramuscular Droperidol,...

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Contributor: Ruben Marrero-Vasquez, PharmD

Educational Pearls:

  • ACEP and FDA have both issued warnings about the viral Tik Tok Benadryl (diphenhydramine) challenge where individuals voluntarily overdose on diphenhydramine which can cause fatal toxicity
  • Diphenhydramine is typically dosed at 0.5-1 mg/kg in pediatric patients Q4-6 PRN and carries a fatal dose of 20-40 mg/kg but anywhere from 3-5x recommended dose does can cause toxicity
  • Diphenhydramine toxicity causes both central and peripheral anticholinergic toxicity
    • Central anticholinergic toxicity symptoms: delirium, agitation, combativeness, confusion, restlessness, hallucinations, ataxia, tremor and seizures
    • Peripheral anticholinergic toxicity symptoms: tachycardia, dry flushed skin, dry mucus membranes, thick secretions, dilation of pupils, urinary retention, and decreased bowel sounds
  • Pneumatic to help you remember anticholinergic toxidrome:
    • Red as a beet
    • Dry as a bone
    • Blind as a bat
    • Mad as a hatter
    • Hot as a hare
    • Full as a flask
  • Management typically only requires supportive care, agitation from central anticholinergic delirium can be hardest aspect to treat, IV benzodiapines are first line treatment to control and may require large doses to prevent rhabdomyolysis and hyperthermia
  • Diphenhydramine toxicity has been associated with blockade of sodium and potentially potassium channels increasing risk of arrhythmia and seizures. Cardiac changes can include: QRS widening, myocardial depression, QT prolongation and torasades-type ventricular tachycardia.
    • Wide QRS complexes indicate delayed ventricular depolarization caused by sodium channel blockade, bolus of sodium bicarbonate can be used dosed 1-2 mEq/kg followed by continuous infusion
    • Prolonged QT: restoration of low serum potassium and magnesium to high normal range
  • Benzodiazipines should be used as first line therapy for toxin induced seizures
    • Don’t use fosphenytoin or phenytoin sodium channel blockers as they can worsen cardiac conduction


  1. Olson KR, Anderson IB, Benowitz NL, Blanc PD, Clark RF, Kearney TE, Kim-Katz SY, Wu AH. Diphenhydramine. In: Poisoning & Drug Overdose. 7th ed.McGraw Hll; 2018: 544-545.
  2. FDA Warns About Serious Problems With High Doses Of The Allergy Medicine Diphenhydramine (Benadryl).(09/24/2020). CDC website. Accessed December 01, 2020. https://www.fda.gov/drugs/drug-safety-and-availability/fda-warns-about-serious-problems-high-doses-allergy-medicine-diphenhydramine-benadryl.
  3. Su M, Goldman M. Anticholinergic Poisoning. UpToDate. https://www.uptodate.com/contents/anticholinergic-poisoning?search=diphenhydramine overdose&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1. Published October 6, 2020. Accessed December 26, 2020.

Summarized by Mason Tuttle