A 23-yeаr-оld client is brоught tо the emergency depаrtment аfter attending a music festival. The client is agitated, diaphoretic, and hypertensive, with rapid eye movements and reports of intense visual hallucinations that began approximately 40 minutes after ingesting a "white powder." The client describes feeling detached from reality and states that colors are "breathing." Shortly after arrival, the client develops a brief tonic-clonic seizure. There is no history of opioid use or alcohol intoxication.Based on the comparative acute effects and administration routes of commonly misused substances, which substance is most consistent with this presentation?