1. Sympathomimetic Toxidrome Presentation - New Onset Seizure/ Status
Epilepticus and Prolongation of QTc Due Too Over-The-Counter Substance Abuse
Frank W Meissner, MD, RDMS, RCMS; Cynthia Garza, JD, MD; Sarah L Martin, MD
Department of Psychiatry
• 24 year-old male college student developed grand mal seizures
• Roommate ‘He was ‘Doing Triple-C’s’(Coricidin™) to get ‘high’ all day!’
• On scene 3 grand mal seizures observed by EMS, gave IV Diazepam 10 mg X 2 enroute to ED.
• Glasgow Coma: 8 (Eyes – pain(2) (pupils mydriasis), Verbal - None(1), Motor – pain withdraws (4)).
• ABG @ arrival - pH <6.707, pCO2 71 mmHg, pO2 105 mmHg. Urine toxic screen negative. ETOH level
58 mg/dl, Lactic acid > 12.2 mmol/L, Salicylate/Acetaminophen negative, TSH 1.25 mIU/L, nml lytes.
• Rx - Immediate orotracheal intubation, 4 grams Magnesium Rapid IV + Bicarb Infusion.
• Due to ease of availability, euphoric high, & hallucinogenic effects, DXM (dextromethorphan) enjoys
world-wide popularity amongst recreational drug abusers. (Shafi H., et al, Deaths due to abuse of
dextromethorphan sold over-the-counter in Pakistan. Egyptian Journal of Forensic Sciences (2016) 6, 280–283.)
• At ED presentation multiple pathways to death, ICU & ventilator support X 7D’s.
• Abusers often refer to Coricidin™ HBP Cough & Cold as ‘Triple C’s’ because of three Cs imprinted on the red
tablets, slang terms include skittles, dex, candy, and red devils. DXM abuse also known as “robotripping. ”
2. • Annual rate of single-substance DXM intentional abuse calls tripled Y2000-06 plateaued Y2006-15. Max
abuse call rate was in 14–17 yr-old’s, mean annual number calls=1761/yr - annual rate 103.6 calls per
million population. Y2006-15, rate of single-substance DXM abuse calls in 14–17 yr-old’s decreased
56.3% - 143.8 => 80.9 calls per million population. (Karami S, et al. Trends in dextromethorphan cough and
cold products: 2000-2015 National Poison Data System intentional abuse exposure calls. Clin Tox; 2018, 56(7),
656-663)
• Kaplan, et al reported 1st case of DXM induced pQTc. (Kaplan B, et al, QTc prolongation due to
dextromethorphan, Int J Cardiol (2010), May 5;148(3):363-4.)
• This case represents second described case of prolonged QTc due to DXM ingestion.
Initial EKG 162 bpm,
regular tachycardia,
normal QRS axis,
normal EKG
intervals other than
pQTc 512-msec.
“Triple C’s.”=>
Department of Psychiatry
3. • DXM is a dextrorotatory isomer of 3-methoxy-N-methyl-methorphan & structurally related to codeine but is
lacking analgesic activity. It is a NMDA receptor antagonist, like ketamine & phencyclidine; the dissociative &
hallucinogenic effects of DXM are due to its binding to the NMDA receptor. It is metabolized in the liver by
CYP2D6 to dextrorphan and by CYP3A4/5 to 3-methoxymorphinan.
• DXM also has competitive 5HT1 agonist activity & inhibits serotonin reuptake; thus potentially
interacting with selective serotonin reuptake inhibitors. Co-administration or overdosing or co-
ingestion of drugs with serotonergic effects can result in life threatening serotonin syndrome. (Navarro
A, Perry C, Bobo WV. A case of serotonin syndrome precipitated by abuse of the anticough remedy dextromethorphan in a
bipolar patient treated with fluoxetine and lithium. Gen Hosp Psychiatry 2006;28(1):78–80.)
• Only a limited number of deaths have been attributed specifically to dextromethorphan. (Logan, et al. Five Deaths
Resulting from Abuse of Dextromethorphan Sold Over the Internet. Journal of Analytical Toxicology, Vol. 33, March 2009).
• No specific antidote is available for dextromethorphan OD, although administration of Narcan is not
unreasonable due to common co-ingestion of narcotics. (Caffery CR , Lank PM. When good times go bad: managing
'legal high' complications in the emergency department. Open Access Emergency Medicine 2018:10 9–23.)
• Successful management in this case centered around aggressive management of his severe lactic acidosis, his
repetitive seizures, as well as prompt reversal of his QTc prolongation.
Department of Psychiatry