As a healthcare worker Ive seen it happen or did when I worked EMS. Guys lighting up what they thought was just some herb but turned out either their dealer or somebody in the distribution line had laced it with PCP.. Sad but true you cant always trust your friendly neighborhood maryjane dealer folks. Had a call even weirder one time. Girl had popped 32 unisom which is like 1600 mg of benedryl and yes can easily be fatal (benedryl in high enough doses shuts down the parasympathetic nervous system and as such can cause hypertensive crisis, extreme tachycardia and death by stroke or heart attack) turned out the girl had PCP in her system started to flip out and thought the unisom/benedryl would counteract the PCP but the high doses did nearly the opposite and nearly killed her at age 15.
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