Which symptom is commonly seen in opiate intoxication?

In opiate intoxication, constricted pupils, also known as miosis, is a hallmark symptom. Opiates, such as morphine and heroin, activate the μ-opioid receptors in the brain, leading to various effects, one of which is the constriction of the pupils. This is a classic sign used by clinicians to assess for opiate use or intoxication.

In contrast, increased energy is not characteristic of opiate intoxication; rather, opiates typically cause sedation and a feeling of calmness or euphoria. Similarly, anxiety is more commonly associated with withdrawal from opioids or other stimulants, rather than intoxication, which tends to produce a state of relaxation. Rapid heartbeat or tachycardia is also not a common feature of opiate intoxication; instead, opiates often cause bradycardia, or a slowed heart rate. Thus, the presence of constricted pupils serves as a clear indicator of opiate intoxication.