Toxicology - nontraumatic rhabdomyolysis

Q: Over-dose of which of the following agent causes non-traumatic rhabdomyolysis? 

A) physostigmine 
B) Acetaminophen 
C) Salicylate levels 
D) Diphenhydramine 
E) Doxylamine


Answer: E

Doxylamine is an antihistamine, and its accidental over-dose is common as it is found in over-the-counter sleeping aids. This agent is unique, with property of causing nontraumatic rhabdomyolysis.

Co-ingestion of acetaminophen, salicylate, and diphenhydramine (choices B, C, and D) are common as people intend to take them with sleep-aids but none of them are known to cause nontraumatic rhabdomyolysis. Elevated CPK levels should raise the concern for Doxylamine ingestion.

Physostigmine (choice A) is neither readily available nor it causes nontraumatic rhabdomyolysis. Likelihood of its overdose from over the counter setting is very low.

#toxicology


References:

1. Mendoza FS, Atiba JO, Krensky AM, Scannell LM. Rhabdomyolysis complicating doxylamine overdose. Clin Pediatr (Phila) 1987; 26:595. 

2. Soto LF, Miller CH, Ognibere AJ. Severe rhabdomyolysis after doxylamine overdose. Postgrad Med 1993; 93:227. 

3. Frankel D, Dolgin J, Murray BM. Non-traumatic rhabdomyolysis complicating antihistamine overdose. J Toxicol Clin Toxicol 1993; 31:493. 

4. Leybishkis B, Fasseas P, Ryan KF. Doxylamine overdose as a potential cause of rhabdomyolysis. Am J Med Sci 2001; 322:48.