Which finding indicates opioid intoxication in a client with substance use disorder?

Pinpoint pupils are a classic sign of opioid intoxication. When opioids bind to their receptors in the central nervous system, one of the physiological effects is the constriction of the pupils, resulting in the characteristic small size of the pupils known as miosis. This finding is particularly strong in cases of opioid overdose but can also be present during intoxication.

In contrast, rapid heart rate, increased energy levels, and excessive sweating are not typical signs of opioid intoxication. Rapid heart rate may be associated with stimulant use or withdrawal from certain substances, while increased energy levels are more often linked to stimulant drugs like cocaine or amphetamines. Excessive sweating can occur with various withdrawal states or medical conditions but isn't a defining characteristic of opioid intoxication. Thus, pinpoint pupils serve as a clear indicator in recognizing someone who may be under the influence of opioids.