Which of the following is NOT a sign of opioid poisoning?

In the context of opioid poisoning, the symptoms typically manifest as central nervous system depression, which includes a set of specific signs. Small pupils, extreme drowsiness or unresponsiveness, and respiratory depression are all classic indicators of opioid intoxication.

Small pupils, or miosis, occurs due to the effect of opioids on the brain, leading to constriction of the pupils. Extreme drowsiness or unresponsiveness is a direct result of opioids' depressant effect on the central nervous system, indicating the person’s level of consciousness is significantly affected.

On the other hand, rapid breathing is not a symptom of opioid poisoning; in fact, opioids usually lead to respiratory depression, which manifests as slowed or shallow breathing. Chest tightness is also unrelated to opioid poisoning. It is more often associated with other conditions like anxiety, asthma, or cardiac issues rather than the effects of opioids. Recognizing these specific signs is crucial for effective assessment and management of a potential opioid overdose.