Which opioid receptor agonist has anticholinergic properties?

Which opioid receptor agonist has anticholinergic properties?

• A. Morphine
• B. Fentanyl
• C. Sufentanil
• D. Meperidine

Answer: (D)

Meperidine stands out because it has noticeable antimuscarinic (anticholinergic) activity among common opioids. That means it can block muscarinic receptors or otherwise reduce acetylcholine effects, leading to tachycardia, dry mouth, urinary retention, and pupil dilation. These anticholinergic effects can blunt some opioid-induced biliary spasm, which is why meperidine is sometimes chosen when that concern is present. Other typical opioid agonists like morphine, fentanyl, and sufentanil do not have meaningful anticholinergic activity, so they don’t produce those muscarinic-related effects. Keep in mind meperidine’s own risks, such as normeperidine accumulation and potential seizures with renal impairment or prolonged use.

Meperidine stands out because it has noticeable antimuscarinic (anticholinergic) activity among common opioids. That means it can block muscarinic receptors or otherwise reduce acetylcholine effects, leading to tachycardia, dry mouth, urinary retention, and pupil dilation. These anticholinergic effects can blunt some opioid-induced biliary spasm, which is why meperidine is sometimes chosen when that concern is present. Other typical opioid agonists like morphine, fentanyl, and sufentanil do not have meaningful anticholinergic activity, so they don’t produce those muscarinic-related effects. Keep in mind meperidine’s own risks, such as normeperidine accumulation and potential seizures with renal impairment or prolonged use.