An 18-year-old boy is brought to the emergency department by his mother due to his strange behavior. The mother says that he laughs inappropriately and seems sluggish. The boy has recently been hanging out with a new group of friends that he describes as "really cool." He has also stopped attending family events and appears apathetic about his schoolwork. When asked in private, the boy admits smoking marijuana. Which of the following physiologic effects is most likely to be observed in this patient?

Question

An 18-year-old boy is brought to the emergency department by his mother due to his strange behavior.  The mother says that he laughs inappropriately and seems sluggish.  The boy has recently been hanging out with a new group of friends that he describes as "really cool."  He has also stopped attending family events and appears apathetic about his schoolwork.  When asked in private, the boy admits smoking marijuana.  Which of the following physiologic effects is most likely to be observed in this patient?

Quizplus · Accepted Answer

Marijuana (cannabis) is one of the most commonly used drugs in the United States. It is a cannabinoid that contains the active ingredient tetrahydrocannabinol (THC). Smoking is the preferred route of delivery, and once inhaled, marijuana produces effects that last from 1-4 hours. THC stimulates cannabinoid receptors (CB1 and CB2 receptors) to produce effects on mood, perception, and cognition. Marijuana produces a mild euphoria with inappropriate laughter, sedation, slowed reflexes, impaired motor coordination, distorted sensory perceptions, and cognitive impairment (decreased attention, concentration, short-term memory, and judgment). The most characteristic physiological signs of marijuana intoxication are conjunctival injection (red eyes), tachycardia, increased appetite, and dry mouth. Marijuana is metabolized in the liver, distributed and stored in lipophilic tissues, and slowly released. It remains in the body for a long time; depending on the amount and frequency of use, it can be detected in the urine up to 30 days after daily use has ceased. (Choices A and F) Cannabis intoxication results in tachycardia and does not cause respiratory depression. Bradycardia can occur with GHB (gamma hydroxybutyric acid), opiate, or benzodiazepine intoxication. In toxic doses, all three central nervous system depressants can cause respiratory depression. (Choice C) Miosis (constricted, pinpoint pupils) is commonly seen in opiate intoxication. (Choice D) Mydriasis (dilated pupils) occurs in cocaine intoxication and opiate withdrawal. (Choice E) Nystagmus is a rhythmic, regular oscillation of the eyes and is commonly seen with phencyclidine (PCP) intoxication. Educational objective: Marijuana contains tetrahydrocannabinol, which stimulates cannabinoid receptors to produce a mild euphoria with inappropriate laughter, increased appetite, slowed reaction time/motor speed, and cognitive impairment. Tachycardia and conjunctival injection are the 2 most immediate physical symptoms of marijuana use.

An 18-Year-Old Boy Is Brought to the Emergency Department by His