Features of opioids include:

• A. Sedation, analgesia, antitussive, reversible
• B. Only analgesia
• C. Cause hyperthermia in all species
• D. No respiratory effects

Answer: (A)

Opioids provide several characteristic effects: they produce analgesia by activating mu receptors in the central nervous system, which dulls pain signals. They also cause sedation because of CNS depressant effects, and they have an antitussive action by suppressing the cough center. A key clinical feature is that their effects are reversible with opioid antagonists (like naloxone), allowing rapid reversal if needed.

It’s important to note that their profile isn’t limited to these effects. They often cause respiratory depression, which is a major risk, and temperature changes vary by species and drug rather than being universal. Hyperthermia in all species is not supported by how opioids behave across animals.