Which of the following signs is commonly associated with acute opioid intoxication?

Which of the following signs is commonly associated with acute opioid intoxication?

• A. Hyperactive behavior
• B. Mydriasis
• C. Nystagmus
• D. Myosis (pinpoint pupils)

Answer: (D)

Pinpoint pupils are a hallmark of acute opioid intoxication. Opioids activate mu receptors in the brainstem, which increases parasympathetic activity and leads to pupil constriction. This constricted (pinpoint) pupil is often seen together with central nervous system depression and respiratory rate reduction, making it a classic clue for opioid effects. In contrast, hyperactive behavior is more typical of stimulant intoxication; dilated pupils (mydriasis) point to sympathetic stimulation from substances like cocaine or amphetamines; nystagmus is not a characteristic sign of opioid use and is more associated with other drugs or intoxications.

Pinpoint pupils are a hallmark of acute opioid intoxication. Opioids activate mu receptors in the brainstem, which increases parasympathetic activity and leads to pupil constriction. This constricted (pinpoint) pupil is often seen together with central nervous system depression and respiratory rate reduction, making it a classic clue for opioid effects.

In contrast, hyperactive behavior is more typical of stimulant intoxication; dilated pupils (mydriasis) point to sympathetic stimulation from substances like cocaine or amphetamines; nystagmus is not a characteristic sign of opioid use and is more associated with other drugs or intoxications.