Methadone versus Suboxone for medication assisted treatment? Similarities, differences, why would you prescribe one over the other?
I'll answer these two together since there's a lot of overlap.
Methadone, Suboxone, and Naltrexone are all medications used in the treatment of opioid use disorder.
Methadone is a full opioid that replaces the opioid the person was using, which prevents withdrawal and helps curb cravings. For example, if a person was using fentanyl and they started taking methadone, they would not withdraw and would no longer have to spend their time and resources trying to get and use fentanyl, which would allow them to participate in work, school, or family. This often allows the person to use less fentanyl or become completely abstinent if that is their goal.
In the US, methadone has to be prescribed and dispensed at a designated opioid treatment program (OTP), also called a methadone clinic. A doctor in a regular doctors office cannot prescribe it for opioid use disorder, and a regular pharmacy cannot dispense it. Methadone is dispensed as an oral liquid medication directly from the clinic where it is prescribed.
A person does not have to be in withdrawal or abstinent from opioids when they start methadone, but they do have to be abstinent from alcohol and benzodiazepines while they are taking it, as these can interact and potentially be fatal.
Suboxone is a mixture of buprenorphine (a partial opioid) and naloxone (which makes it not do anything if snorted or injected). For the purposes of this post, we're just going to talk about the buprenorphine part.
Buprenorphine is an opioid, but unlike "full" opioids like methadone, oxycodone, or heroin, it only partially covers the opioid receptors in the brain. This means it doesn't cause euphoria or respiratory depression on it's own, but still replaces the opioid so the person doesn't go into withdrawal or get cravings.
It also sticks really tightly to those receptors, so it knocks any other opioid off them and takes its place. That means if a person takes a different opioid while on buprenorphine, it won't get them high or cause them to overdose. Like methadone, a person has to be abstinent from alcohol and benzodiazepines in order to take buprenorphine safely.
Buprenorphine can be prescribed by a doctor in a regular doctor's office and dispensed at a regular pharmacy. The one caveat to this is that if started when a person still has a different opioid in their system, it will instantly cause severe withdrawal. This means a person has to be in active withdrawal before buprenorphine can be started.
For heroin, this might be about 12 hours since last use. For fentanyl however, this might be up to three days since last use, which can be extremely uncomfortable. Methadone does not have this requirement, as it does not cause withdrawal.
Buprenorphine is dispensed as a film or pill that dissolves in the mouth (it doesn't work if swallowed). It can also be given as a once-a-month shot.
Naltrexone works by completely blocking opioids in the brain. It doesn't matter if the person takes them because they won't get high or overdose. It also blocks the opioids the brain produces when thinking about using opioids, which makes using opioids less tempting and reduces cravings.
In order to take naltrexone, a person has to be completely off opioids, or they will go into severe withdrawal as naltrexone blocks all the opioid receptors.
Naltrexone can be prescribed in a normal doctor's office and dispensed at a normal pharmacy. It is usually a pill, but it also can be given as a once-a-month shot.
