Welcome to 2-minute neuroscience, where I explain neuroscience topics in 2 minutes or
In this installment I will discuss methadone.
Methadone is best known for its use in the treatment of opioid addiction, although it
can also be used for treating chronic pain.
It’s usually administered by mouth in the form of a liquid, pill, or sublingual tablet.
Methadone’s primary mechanism of action is as an agonist at opioid receptors.
In other words, it activates opioid receptors similar to the way other opioid drugs like
It also acts as an antagonist, or blocks, NMDA glutamate receptors, which is thought
to contribute to its pain-relieving effects.
Because it has a similar mechanism of action to other opioids, methadone causes enough
stimulation of opioid receptors to reduce cravings for other opioid drugs and to prevent
a patient from experiencing withdrawal symptoms.
Unlike most other opioids, however, methadone typically only has to be administered once
a day to achieve these effects.
Additionally, methadone occupies opioid receptor binding sites, which diminishes any effect
administration of another opioid might have, further discouraging someone from using other
opioid drugs while taking methadone.
Altogether, methadone’s pharmacological action lowers the likelihood a patient will
abuse other opioid drugs.
Since methadone has a similar mechanism of action to other opioids, patients also often
become dependent on methadone, and some may need to take the drug for a prolonged period
of time, or even for the rest of their life.
Because the drug is administered by a medical professional, however, doses can be controlled,
and the risk of fatal and nonfatal overdose for someone on methadone is much lower than
for someone who continues abusing opioids.
Additionally, methadone treatment is associated with a reduction in intravenous drug use,
and thus a lower risk of contracting blood-borne diseases like HIV.