A nurse is caring for a client who has been brought into an emergency department of a large hospital. The client's family state that the client "took some kind of drugs." The client is dizzy, has recently vomited, and is experiencing paranoia, yelling, "Stay away from me! You are going to kill me!" The client alternates yelling with mumbling and gesturing. Their eyes are darting back and forth as they are talking to the wall. The nurse should suspect the client has used which of the following substances?

A. Stimulants. Stimulant intoxication typically causes increased energy, agitation, tachycardia, and paranoia, but it does not usually induce hallucinations to the extent described. While severe stimulant use (e.g., methamphetamine or cocaine) can cause paranoia, the significant perceptual disturbances and visual hallucinations suggest a different category of drugs. B. Opioids. Opioid intoxication generally leads to central nervous system depression, respiratory depression, pinpoint pupils, and sedation rather than paranoia, hallucinations, and erratic behavior. The described symptoms do not align with opioid use. C. Hallucinogens. Hallucinogen use, such as LSD or PCP, can cause altered perception, paranoia, visual hallucinations, and erratic behavior. The client’s symptoms—paranoia, visual disturbances, mumbling, and gesturing—are characteristic of hallucinogen intoxication, making this the most likely cause. D. Anabolic steroids. Anabolic steroid use can lead to mood swings, aggression, and psychotic symptoms in some cases, but it does not typically cause acute hallucinations, paranoia, or perceptual disturbances. The symptoms described do not fit anabolic steroid use.