Pharmacology for Nurses · Substance Use Disorder Treatment Drugs
Alcohol Use Disorder Drugs
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In 30 seconds
Alcohol use disorder (AUD) is treated with behavioral therapy plus medications that take three broad approaches:
- Aversive therapy (disulfiram): makes drinking physically unpleasant, discouraging use through conditioning.
- Anti-craving therapy (naltrexone): blunts alcohol's rewarding effect, reducing Craving Intense desire to drink Full entry → and heavy drinking days.
- Relapse-prevention therapy (acamprosate): helps the brain's glutamate system rebalance during abstinence.
Separately, withdrawal management — typically using GABA-enhancing agents such as benzodiazepines under medical supervision — addresses the dangerous acute phase when a person with heavy chronic use stops drinking. To understand these you need two pieces of neurochemistry: what alcohol does to the brain, and what the brain does in response.
Why this matters
AUD is among the most prevalent substance use disorders nurses will encounter — on medical-surgical units, in the ED, and in primary care. Two facts make this topic urgent:
- Alcohol withdrawal can kill. In heavy, chronic drinkers, abrupt cessation can trigger seizures, and severe cases progress to Delirium tremens Severe, life-threatening withdrawal with confusion, agitation, hallucinations, autonomic instability Full entry → (confusion, agitation, hallucinations, autonomic instability) — a medical emergency nurses often recognize first.
- Medications change outcomes: naltrexone and acamprosate, combined with counseling, meaningfully reduce heavy drinking and support abstinence.
The college version
Core Concepts
What alcohol does to the brain: GABA up, glutamate down
Alcohol is a CNS depressant with two key molecular actions: it enhances GABA-A receptor The brain's main "brake" receptor; alcohol and benzodiazepines enhance it Full entry → signaling (GABA is the brain's main inhibitory neurotransmitter, so this slows activity) and it blocks NMDA-type glutamate receptors (glutamate is the main excitatory neurotransmitter, so this also slows excitation). The result: relaxation, slurred speech, impaired coordination.
With chronic heavy exposure the brain compensates (neuroadaptation): it becomes more excitable to push back against the drug. That is why tolerance develops — and why sudden removal leaves the brain hyper-excited: the tremor, anxiety, rapid heart rate, seizures, and delirium of withdrawal.
Disulfiram: the aversive approach
Disulfiram does not reduce craving and has no effect on intoxication. It inhibits Aldehyde dehydrogenase The enzyme that clears acetaldehyde Full entry →, the enzyme that breaks down Acetaldehyde The toxic first breakdown product of alcohol Full entry → (alcohol's first metabolite). A person who drinks while taking disulfiram accumulates acetaldehyde and within minutes develops flushing, throbbing headache, nausea and vomiting, sweating, palpitations, and a drop in blood pressure. The goal is aversion: drinking becomes something to avoid.
Nursing points: disulfiram only works if the person takes it and stays alcohol-free — including hidden alcohol sources such as some mouthwashes, cough syrups, and cooking wines. Patients must be fully informed and alcohol-free when starting.
Naltrexone: reducing the reward
Naltrexone — the same drug class used for OUD — also helps in AUD because alcohol's reward depends partly on the endogenous opioid system. Drinking releases endorphins that activate opioid receptors and contribute to the dopamine reward. By blocking mu-opioid receptors, naltrexone blunts that reward: drinking becomes less pleasurable, craving drops, and heavy drinking days decrease. Contrast with disulfiram: naltrexone targets why the person wants to drink, not the consequence of drinking. Dosing and monitoring are prescriber decisions.
Acamprosate: stabilizing the glutamate system
Acamprosate is thought to act on the glutamate (excitatory) system — the side of the balance that runs hot during early abstinence. By modulating NMDA-type glutamate signaling, it reduces the discomfort of early abstinence (sleep disturbance, anxiety, dysphoria) and helps maintain abstinence once achieved. It produces no aversive reaction and does not block alcohol's acute reward; think of it as a "stabilizer" for a nervous system rebalancing after chronic exposure. Because it is renally excreted, renal function affects dosing (per prescriber order).
Withdrawal management: the role of GABAergic agents
The mainstay class for acute alcohol withdrawal is benzodiazepines (and related GABA-enhancing agents in monitored settings). They substitute for alcohol's GABA-enhancing effect, calming the hyper-excited brain and preventing seizures and delirium tremens. Management is typically symptom-driven: a validated scale (e.g., CIWA-Ar-type) rates severity, and medication is given per protocol and provider orders with frequent reassessment. Nursing watchpoints: level of consciousness, respiratory status (benzodiazepines can cause oversedation), fall risk, and hydration/nutrition — thiamine is commonly given per protocol in this context.
Nursing considerations
- Screen and assess: ask about quantity, frequency, and last drink nonjudgmentally; patients often under-report.
- Monitor for withdrawal: early signs (tremor, anxiety, sweating, tachycardia, insomnia) can appear hours after the last drink — report promptly.
- Educate about strategies: aversive (disulfiram) vs. anti-craving (naltrexone) vs. stabilizing (acamprosate), so patients know what to expect and why adherence matters.
- Teach alcohol–drug interactions: alcohol potentiates CNS depressants, and many medications carry alcohol warnings.
- Use person-first language; protocols and treatment settings vary by institution and jurisdiction.
Safety note: This is an educational overview of drug classes and mechanisms. Alcohol withdrawal is potentially life-threatening and must be managed under medical supervision with validated protocols. Doses, routes, and monitoring schedules are determined by prescribers — verify all information against current references, the facility formulary, and prescriber orders.
Common Confusions
| Do not confuse | With | Difference |
|---|---|---|
| Disulfiram reaction | Hangover | A hangover is dehydration/metabolite effects; the disulfiram reaction is rapid acetaldehyde buildup (flushing, vomiting, hypotension) that occurs only if the person drinks while on disulfiram |
| Naltrexone for AUD | Naltrexone for OUD | Same drug, same receptor, different indication; in AUD it blunts alcohol's reward — one use doesn't "cover" the other |
| Benzodiazepines "cure" alcohol addiction | Benzodiazepines manage withdrawal | They substitute for alcohol's GABA effect short-term to prevent seizures/delirium; they are not long-term treatment |
| Detoxification | Treatment of AUD | Detox stabilizes acute withdrawal; relapse rates stay high without ongoing medication and counseling |
| Acamprosate | Disulfiram | Acamprosate stabilizes glutamate and supports abstinence; disulfiram makes drinking aversive — opposite strategies |
Eli explains
The same idea, in plain words
Explain it like I’m 10
Alcohol slows the brain down, like turning down the volume on a radio. If the brain hears the volume turned down for years, it turns its own volume up to compensate. When the person stops drinking, the brain is suddenly too loud — that's withdrawal, and it can be dangerous. Medicines help in three ways: one makes drinking taste awful (disulfiram), one makes drinking less fun so the person wants it less (naltrexone), and one helps the brain settle back to a normal volume (acamprosate).
Worked example
Mr. Osei, 58, is admitted with pancreatitis and reports drinking "a six-pack or more daily for years," last drink this morning. Within hours the nurse notes tremor, sweating, and a rising pulse — early withdrawal signs. She reports promptly; the provider orders a symptom-triggered withdrawal protocol using a validated scale and a benzodiazepine, and the nurse reassesses frequently, giving thiamine per protocol and watching for oversedation. At discharge teaching she explains the difference between withdrawal management and longer-term options (naltrexone, acamprosate, or disulfiram): "one helps with the wanting, one steadies the brain, and one makes drinking unpleasant" — and refers him to counseling.
Key takeaways
- Alcohol enhances GABA-A (inhibitory) and blocks NMDA glutamate (excitatory) signaling — why it sedates, and why chronic use causes rebound hyper-excitation in withdrawal.
- Disulfiram = aversive therapy: inhibits aldehyde dehydrogenase → acetaldehyde buildup → flushing, nausea, palpitations after drinking. Requires strict avoidance of all alcohol sources (mouthwash, cough syrup, cooking wine).
- Naltrexone = anti-craving: blocks mu-opioid receptors, blunting alcohol's reward; same receptor target used in OUD treatment.
- Acamprosate = stabilizer: modulates glutamate signaling to support abstinence; renal function affects dosing.
- Benzodiazepines are the mainstay class for alcohol withdrawal management — per symptom-triggered protocols in monitored settings, to prevent seizures and delirium tremens.
- Withdrawal can be fatal (seizures, delirium tremens) — early recognition and protocol-driven care are nursing essentials.
- Detox ≠ treatment: withdrawal management stabilizes; medication plus counseling changes the course.
- Verify all doses, protocols, and interactions against current references, the formulary, and prescriber orders.
Check yourself
6 review questions from the chapter. Try each one, then open the answer.
Explain how alcohol's effects on GABA-A and NMDA receptors produce sedation — and why chronic use leads to dangerous withdrawal.
Show answer
Alcohol enhances inhibitory GABA-A signaling and blocks excitatory NMDA glutamate signaling, slowing the brain. Chronic heavy use triggers neuroadaptation (a more excitable brain); when alcohol is removed, the brain is hyper-excited — tremor, tachycardia, and in severe cases seizures and delirium tremens.
What is disulfiram's mechanism, and why must patients avoid even "hidden" sources of alcohol?
Show answer
Disulfiram inhibits aldehyde dehydrogenase, so acetaldehyde accumulates when alcohol is consumed, causing an intense unpleasant reaction. Even small amounts of alcohol (mouthwash, cough syrup, cooking wine) can trigger it.
How does naltrexone reduce drinking, and why is it anti-craving rather than aversive?
Show answer
Naltrexone blocks mu-opioid receptors, reducing the endogenous-opioid component of alcohol's reward, which decreases craving and heavy drinking. It does not make drinking feel sick — it makes it less rewarding.
What class of medications is the mainstay for acute alcohol withdrawal, and what is the goal?
Show answer
Benzodiazepines (GABA-enhancing agents); they prevent seizures and progression to delirium tremens by calming the hyper-excited brain, typically per symptom-triggered protocol.
Why is thiamine commonly part of alcohol-related care, and what is a key watchpoint when benzodiazepines are used for withdrawal?
Show answer
Thiamine addresses nutritional deficiency common in heavy drinkers (preventing Wernicke-type complications). With benzodiazepines, watch for oversedation and respiratory depression, especially early in withdrawal.
Why is detoxification alone insufficient treatment for AUD?
Show answer
Detox stabilizes acute withdrawal but leaves craving and neuroadaptation untreated; sustained recovery typically requires medication (naltrexone, acamprosate, or disulfiram) plus counseling and support.
Study tools & related lessonsKey vocabulary · Related
Key vocabulary
- GABA-A receptor
- The brain's main "brake" receptor; alcohol and benzodiazepines enhance it
- NMDA receptor
- A major "gas pedal" (glutamate) receptor; alcohol blocks it
- Acetaldehyde
- The toxic first breakdown product of alcohol
- Aldehyde dehydrogenase
- The enzyme that clears acetaldehyde
- Disulfiram reaction
- Flushing, nausea, palpitations, hypotension after drinking on disulfiram
- Craving
- Intense desire to drink
- Delirium tremens
- Severe, life-threatening withdrawal with confusion, agitation, hallucinations, autonomic instability
- Withdrawal scale
- Validated symptom-rating tool (e.g., CIWA-Ar-type) guiding withdrawal treatment
Sources & references
This lesson was adapted from the open educational references above; their licenses and attributions are preserved. See Copyright & Licensing.
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