Just like benzodiazepines, alcohol can be fatal when consumed by a patient who also takes methadone.
These two substances interact in several ways.
Worst of all, alcohol inhibits the area of the brain that keeps us breathing while we sleep. So do opioids of all sorts, including methadone. But when alcohol and methadone are both in the blood stream, the effects are greater than expected, due to synergy. In other words, 1+1=3, instead of 2, as we would expect. This interaction is unpredictable. This is how overdose deaths occur with the combination of alcohol and methadone.
Besides this potentially fatal interaction, alcohol also induces, or speeds up, the metabolism of methadone. Both alcohol and methadone are metabolized by the same enzymes in the liver, and alcohol can prime the pump of the metabolic rate. Alcohol gooses the liver, speeding the metabolism of methadone, which means a patient on a previously stable dose of methadone may suddenly notice that his dose isn’t holding for the full 24 hours. This patient may ask for a dose increase, when in truth, he really needs to stop drinking alcohol completely.
Over the long term, alcohol can cause a buildup of methadone to a toxic level, if the drinking goes on long enough to cause liver scarring and shrinkage, called cirrhosis. If this condition develops, liver metabolism slows for any drug or medicine processed by the liver.
Addiction is cunning, baffling, and powerful. It’s incredible to think of a person who’s able to stop using opioids after years of addiction be defeated by alcohol. Cross addiction, which means switching from one addictive drug to another, happens all too frequently. Sometimes it’s hard to convince patients they need to stop the use of all addicting drugs, and that does include alcohol and marijuana.