Which statement about methadone is true?

Which statement about methadone is true?

• A. It is a synthetic opioid agonist with NMDA antagonism that can treat opioid abstinence syndromes and reduce pain and cravings.
• B. It is rapidly cleared renally with minimal hepatic metabolism.
• C. It has low oral bioavailability and a short half-life.
• D. It is a natural opioid with no NMDA activity.

Answer: (A)

Methadone works because it combines mu-opioid receptor activation with NMDA receptor antagonism and has a long duration of action. As a synthetic opioid agonist, it provides steady opioid effects that blunt withdrawal symptoms and cravings, which is why it’s used for opioid abstinence syndromes and maintenance therapy. The NMDA antagonism helps mitigate opioid tolerance and hyperalgesia, contributing to its usefulness in both pain management and long-term treatment by reducing the need for escalating doses. In terms of how it behaves in the body, methadone is mainly cleared by the liver, with extensive hepatic metabolism via cytochrome P450 enzymes; renal excretion plays only a minor role. It also has good oral bioavailability and a long half-life (roughly 24–36 hours, sometimes longer), which supports daily dosing and stable plasma levels. It is not a natural opioid; it is synthetic, and it indeed has NMDA activity, so the statement describing it as a synthetic opioid agonist with NMDA antagonism that can treat opioid abstinence syndromes and reduce pain and cravings is accurate.

Methadone works because it combines mu-opioid receptor activation with NMDA receptor antagonism and has a long duration of action. As a synthetic opioid agonist, it provides steady opioid effects that blunt withdrawal symptoms and cravings, which is why it’s used for opioid abstinence syndromes and maintenance therapy. The NMDA antagonism helps mitigate opioid tolerance and hyperalgesia, contributing to its usefulness in both pain management and long-term treatment by reducing the need for escalating doses. In terms of how it behaves in the body, methadone is mainly cleared by the liver, with extensive hepatic metabolism via cytochrome P450 enzymes; renal excretion plays only a minor role. It also has good oral bioavailability and a long half-life (roughly 24–36 hours, sometimes longer), which supports daily dosing and stable plasma levels. It is not a natural opioid; it is synthetic, and it indeed has NMDA activity, so the statement describing it as a synthetic opioid agonist with NMDA antagonism that can treat opioid abstinence syndromes and reduce pain and cravings is accurate.