M320 (opioid)

M320 is a potent opioid analgesic drug which is a highly selective agonist at the mu opioid receptor. It is a derivative of morphine, but is many times more potent, and has a higher therapeutic index, making it potentially more useful in clinical practice.

Pharmacology

M320 is a full agonist at the mu-opioid receptor, the main therapeutic action site for pain relief. It has a high affinity for this receptor, and produces a typical opioid analgesic effect, with strong analgesia, sedation, and euphoria. It is around 100 times more potent than morphine, and has a longer duration of action.

Chemistry

M320 is a derivative of morphine, with the 3-hydroxy group replaced by a methoxy group, and the 6-hydroxy group replaced by a chlorine atom. This gives it a much higher potency and therapeutic index than morphine.

Clinical Use

M320 is not currently used in clinical practice, but its high potency and therapeutic index suggest that it could be a useful drug for treating severe pain, where other opioids are ineffective or cause unacceptable side effects.

Side Effects

As with all opioids, M320 can cause a range of side effects, including respiratory depression, constipation, nausea, vomiting, and dependence. Its high potency means that these side effects can be severe, and careful monitoring is required in any patients receiving this drug.

See Also

• Opioid
• Morphine
• Mu opioid receptor
• Analgesia