Swift Onset of Central Nervous System Depression and Asystole Followingan Overdose of Guaifenesin

Guaifenesin is an over-the-counter expectorant used for chest congestion and is available both in single-ingredient formulations and in combination with antihistamines, cough suppressants and decongestants. The documented side-effects of guaifenesin are generally mild. We present the case of a 23-year-old female who committed suicide by ingestion of guaifenesin along with small amounts of cetirizine, ethanol and sertraline. Approximately 2 h after ingestion, the patient experienced central nervous system depression followed by asystole. No anatomic cause of death could be determined at autopsy. The initial toxicology detected only ethanol, which was found at a concentration insufficient to cause death. Upon further analysis, guaifenesin was detected in femoral blood at 25.0 μg/mL, urine at >50.0 μg/mL, vitreous fluid at 9.2 μg/mL, brain at 17.0 μg/g and liver at 25.0 μg/g. This is the first reported human case that can be considered a death to which guaifenesin was the significant pharmacologic contributor. Guaifenesin is not detected by the primary screening methods employed by some labs and may be missed in toxicological analyses of overdoses unless specifically suspected.