Detox medications, explained: what each one does, and what it is not.

Authored by the MLJ Clinical Team. Reviewed under board-certified psychiatric oversight. Last updated September 2026.

• Detox medications fall into four jobs: managing the withdrawal itself, making it bearable, reducing the pull back toward use, and repairing what heavy use depleted.
• Some are FDA-approved for these purposes; others are prescribed off-label based on clinical evidence. We will tell you which is which.
• None of them is a cure, and none does the work of treatment. They make the first weeks safe and tolerable enough for that work to begin.
• Several, especially naltrexone, acamprosate, and buprenorphine, are meant to continue well past detox, and at MLJ they do, with the same prescriber.
• This page describes mechanism and role only. Doses, schedules, and choices are individual and are made with you by our board-certified psychiatrist.

• Four jobs a detox medication can do
• Managing the withdrawal: benzodiazepines, buprenorphine, clonidine, gabapentin
• Making it bearable: ondansetron and hydroxyzine
• Reducing the pull back: naltrexone and acamprosate
• Repairing the depletion: thiamine, folate, and the rest
• The reference table
• How medication decisions are made at MLJ

Four jobs a detox medication can do.

People arrive at detox with two opposite fears about medication. One is that they will be handed a cocktail of pills and sedated into compliance. The other is that they will be made to suffer through withdrawal with nothing. Neither describes good care. Good care uses specific medications for specific reasons, explains each one, and stops the ones that are no longer needed.

It helps to sort the medications by job. The first job is managing the withdrawal itself: preventing a seizure, preventing delirium, or substituting for an opioid so that the body is not thrown into overdrive. The second is comfort: nausea, anxiety, insomnia, and muscle aches are not dangerous, but they are what make people leave, and treating them is a clinical act. The third is reducing the pull back toward use once withdrawal has passed, which is where the medications that continue for months live. The fourth is repletion: heavy alcohol use in particular strips the body of vitamins it needs to protect the brain, and replacing them is urgent.

Two notes before the list. Everything here describes how a medication works and what it is for, not how much or how often; those decisions belong to your prescriber and to you. And "off-label" is not a warning sign. It means the FDA approved a drug for one purpose and clinicians, on the basis of research, use it for another. Several of the most useful medications in medical detox are used that way, and we will always tell you when one is.

Managing the withdrawal: benzodiazepines, buprenorphine, clonidine, gabapentin.

Benzodiazepines are the backbone of alcohol withdrawal management and, paradoxically, of benzodiazepine withdrawal too. They enhance GABA, the brain's braking system, which is exactly what alcohol was doing before it was removed. Given in the first days and then reduced, a long-acting benzodiazepine prevents the seizures and delirium that make alcohol withdrawal dangerous. The ASAM alcohol withdrawal guideline treats them as first-line for moderate to severe withdrawal. What they are not: a long-term treatment for anxiety in someone with a substance use disorder, or something you go home with. In detox they are a bridge, and the bridge has an end.

Buprenorphine is a partial opioid agonist. It occupies the same receptors as heroin, oxycodone, or fentanyl, but activates them only partway, enough to stop withdrawal and blunt craving without producing the high or the dangerous respiratory depression of a full opioid. It also binds tightly, which blocks other opioids from acting. SAMHSA's TIP 63 describes it as one of three FDA-approved medications for opioid use disorder. Timing its first dose matters, especially after fentanyl, as explained on our opioid and fentanyl detox page. What it is not: "trading one addiction for another." It is a stabilizing medication with decades of evidence behind it, and for many people it continues for a long time.

Clonidine was developed for blood pressure. It calms the surge of noradrenaline that drives the sweating, racing pulse, anxiety, and gooseflesh of opioid withdrawal, which is why it is used off-label for that purpose. A closely related drug, lofexidine, is FDA-approved specifically for opioid withdrawal symptoms. Neither reduces craving or treats the underlying disorder; they make the acute phase more tolerable and can lower blood pressure too far, so they are used with monitoring. Gabapentin was developed for seizures and nerve pain. In detox it has two roles: as an adjunct in alcohol withdrawal, where it can ease anxiety, insomnia, and mild symptoms, and in some cases beyond detox, where clinical trials have found it can help certain people with alcohol use disorder, particularly those with prominent withdrawal-related insomnia, stay off alcohol. It is not a substitute for a benzodiazepine in severe withdrawal, and it has misuse potential of its own, so it is prescribed deliberately.

Making it bearable: ondansetron and hydroxyzine.

Comfort medications rarely make the medical literature interesting, and they are frequently the reason someone stays past day three. Ondansetron is an anti-nausea medication that blocks a specific serotonin receptor involved in the vomiting reflex. In opioid withdrawal, where nausea and vomiting can be relentless, it prevents dehydration and lets people eat. It is also used in alcohol withdrawal for the same reason. What it is not: a sedative, a treatment for craving, or anything that alters the course of withdrawal. It simply removes one of the most demoralizing symptoms from the picture.

Hydroxyzine is an antihistamine with calming properties. It is used for the anxiety, restlessness, and insomnia of withdrawal when a clinician wants to avoid adding another sedative that carries dependence risk. Its usefulness in detox is precisely that it is not a benzodiazepine or a sleeping pill; it takes the edge off without building a new habit. Its limits are real, though. It can leave people groggy, it does nothing for severe withdrawal, and it is not a long-term answer to anxiety, which is a treatment question rather than a detox question and is taken up in residential treatment.

Other comfort medications appear as needed: something for diarrhea in opioid withdrawal, a muscle relaxant for cramping, an over-the-counter analgesic for aches. None is dramatic. Together, they are the difference between a withdrawal people endure and one they abandon.

Reducing the pull back: naltrexone and acamprosate.

These two are not detox medications in the strict sense. They begin as detox ends and are meant to continue for months. We include them because the decision to start them is made in the first week or two, and because people often confuse them with the medications above.

Naltrexone is an opioid receptor blocker, and it is FDA-approved for both alcohol use disorder and opioid use disorder. For alcohol, blocking those receptors dampens the reward alcohol produces, which for many people translates into fewer heavy-drinking days and less pull toward the second drink. For opioids, it blocks the receptors outright, so that an opioid taken on top of it has little effect; it is available as a monthly injection for this reason. What it is not: something that can be started while opioids are still in the body, since it would trigger sudden withdrawal, which is why timing after opioid detox is deliberate. It is also not a sedative, not habit-forming, and not a medication that makes you feel anything day to day. NIAAA's clinician resource on medications for alcohol use disorder is a good plain summary of the evidence.

Acamprosate is FDA-approved for alcohol use disorder and works on a different system. Long-term heavy drinking leaves the brain's glutamate signaling overactive once alcohol is gone; acamprosate is thought to help restore that balance, easing the low-grade restlessness, poor sleep, and unease of the weeks after detox that drive people back to drinking. It is best begun once withdrawal is complete and works most clearly for people who have already stopped drinking and want to stay stopped. What it is not: a medication that reduces the effect of alcohol if you drink, or one that does anything quickly. Its benefit is quiet and cumulative. Both medications work best alongside therapy, which is the whole premise of the relapse-prevention program that follows detox at MLJ.

Repairing the depletion: thiamine, folate, and the rest.

Heavy drinking impairs the absorption of several vitamins and, because alcohol so often replaces food, depletes them further. The one that matters most urgently is thiamine, vitamin B1. The brain needs it to metabolize glucose, and when it runs short the result can be Wernicke's encephalopathy: confusion, unsteady gait, and abnormal eye movements, which if untreated can progress to a permanent memory disorder. It is entirely preventable, and thiamine is given to every person detoxing from alcohol at MLJ before anything else, including before any glucose-containing fluids, because glucose without thiamine can precipitate the very problem we are preventing. What it is not: a medication you will feel. Its value is in what does not happen.

Folate and the other B vitamins are commonly depleted too, and low folate contributes to the anemia and fatigue that make early recovery feel heavier than it needs to. Magnesium is often low after heavy drinking and is relevant to both cardiac rhythm and the effectiveness of thiamine, so it is checked and replaced. Where nutrition has been poor for a long time, a general multivitamin and a real diet do the rest. Our post on nutrition in alcohol withdrawal goes deeper on the food side of this, which in the Rebuild Method's Body domain is treated as clinical work rather than catering.

The reference table, in one place.

How medication decisions are made at MLJ.

Every medication in this list is prescribed at MLJ by, or under the direct oversight of, a board-certified psychiatrist who has met you, taken your history, and reviewed your labs. Nothing is protocol-by-default. A person detoxing from alcohol with no benzodiazepine history, good nutrition, and mild symptoms may need very little. A person with a long history of both, a prior withdrawal seizure, and weeks of poor eating needs a great deal more, delivered carefully, with vitals checked through the night. With six beds and a true 1:1 ratio, we can tell the difference and act on it.

We also explain. Before any medication is started you will hear what it is for, how it works, whether it is on-label or off, what it will feel like, and when we expect to stop it. You are entitled to say no, and to ask for alternatives, and the conversation about whether to begin a longer-term medication like naltrexone or buprenorphine happens with you, not to you. When you move from detox into residential and later into IOP, the prescriber does not change, which means the reasoning behind each medication travels with you rather than being reconstructed from a chart.

• Medical detox at MLJ — the hub: who needs detox, and what the first week looks like.
• Alcohol withdrawal timeline — where benzodiazepines and thiamine fit hour by hour.
• Opioid and fentanyl detox — buprenorphine induction and the fentanyl timing problem.
• What "medically supervised" means — the nursing and physician structure these medications require.
• Relapse prevention program — where naltrexone and acamprosate do their work after detox.