Examkin

Question

Difficulty: EasySubstance-Related and Addictive Disorders

Match each classic clinical presentation with the most likely corresponding substance intoxication.

  • Miosis, significant respiratory depression, and depressed mental statusOpioid intoxication
  • Mydriasis, marked tachycardia, diaphoresis, and severe psychomotor agitationCocaine intoxication
  • Multidirectional (horizontal and vertical) nystagmus, ataxia, and combative behaviorPhencyclidine (PCP) intoxication
  • Conjunctival injection, increased appetite, and dry mouthCannabis intoxication

Answer

Miosis and respiratory depression correspond to Opioid intoxication. Mydriasis and diaphoresis correspond to Cocaine intoxication. Multidirectional nystagmus corresponds to PCP intoxication. Conjunctival injection corresponds to Cannabis intoxication.
Each clinical presentation perfectly aligns with the physiological effects of the respective substance. Opioids cause parasympathetic dominance in the eye and respiratory depression. Cocaine causes overwhelming sympathetic activation. PCP disrupts NMDA receptors leading to unique multidirectional nystagmus. Cannabis causes characteristic vasodilation in the conjunctiva.

Step-by-Step Solution

1
Identify the toxidrome featuring miosis and respiratory depression.
Matches with Opioid intoxication.
Mu-opioid receptor agonism leads directly to parasympathetic activation in the eye (miosis) and decreased respiratory drive.
2
Identify the toxidrome featuring mydriasis, diaphoresis, and severe agitation.
Matches with Cocaine intoxication.
Sympathomimetic excess from catecholamine reuptake inhibition produces classic fight-or-flight signs, including sweating and large pupils.
3
Identify the toxidrome featuring multidirectional nystagmus and combativeness.
Matches with Phencyclidine (PCP) intoxication.
PCP uniquely produces prominent horizontal and vertical nystagmus accompanied by dissociation and sudden aggressive behavior.
4
Identify the toxidrome featuring conjunctival injection and increased appetite.
Matches with Cannabis intoxication.
THC receptor activation leads to distinctive physical signs like conjunctival vasodilation and increased appetite.

Key Concept

Classic Toxidromes of Common Substances of Abuse
Rate this question

Topics

Substance-Related and Addictive Disorders

More questions from this topic