Substance use disorders: a nursing reference guide

Substance use disorders (SUDs) affect more than 46 million Americans aged 12 or older according to SAMHSA’s 2023 National Survey on Drug Use and Health — roughly 16% of the population. Despite this prevalence, only about 10% of those who need treatment receive it. For nurses, SUDs are not a specialty-unit issue: they surface in every setting from the ED to the surgical floor to the ICU, often undisclosed. Alcohol withdrawal can kill a hospitalized patient whose admission history missed a heavy drinking history. Opioid intoxication can look like a neuro emergency. Stimulant use can masquerade as a hypertensive crisis.

This reference covers the four major substance classes tested on NCLEX and encountered in clinical practice: alcohol, opioids, stimulants, and sedatives/hypnotics. For each class you will find DSM-5 diagnostic criteria, intoxication and withdrawal presentations, validated assessment tools, pharmacological management, and nursing priorities. A cross-cutting section covers motivational interviewing, harm reduction, SBIRT, and anti-stigma documentation. Use this alongside the anxiety disorders reference, depression reference, and bipolar disorder reference for full psychiatric series coverage.

Quick reference: substance classes

Alcohol use disorder

DSM-5 criteria

Alcohol use disorder (AUD) is diagnosed when two or more of the following 11 criteria are present within a 12-month period. Severity is classified as mild (2–3 criteria), moderate (4–5 criteria), or severe (6 or more criteria). The 11 criteria cluster into four domains:

Impaired control: drinking more or longer than intended; persistent desire or unsuccessful efforts to cut down; spending a great deal of time obtaining, using, or recovering from alcohol; craving or strong urge to drink.

Social impairment: failure to fulfill role obligations at work, school, or home; continued use despite persistent social or interpersonal problems caused by alcohol; giving up or reducing important activities.

Risky use: recurrent use in physically hazardous situations; continued use despite knowing it causes or worsens a physical or psychological problem.

Pharmacological criteria: tolerance (needing markedly more alcohol to achieve the same effect); withdrawal symptoms when alcohol is reduced or stopped.

CAGE screening tool

The CAGE questionnaire is a validated four-item screening tool that can be administered in under one minute. It has a pooled sensitivity of approximately 80% and specificity of approximately 89% for detecting alcohol use disorders when a cutoff score of 2 is used (Dhalla & Kopec, 2007).

Scoring: Each “yes” = 1 point. A score of 2 or higher is a positive screen and warrants comprehensive assessment. A score of 3–4 is highly suggestive of AUD.

Alcohol withdrawal timeline

Alcohol withdrawal is a medical emergency that follows a predictable timeline after the last drink. The underlying mechanism is CNS hyperexcitability: chronic alcohol exposure downregulates GABA-A receptors and upregulates NMDA receptors, so abrupt cessation removes inhibitory tone, producing excitatory rebound.

Note: The timeline is an approximation. Patients with a history of prior withdrawals may progress faster and more severely (“kindling effect”). Always ask about prior withdrawal seizures or DTs.

CIWA-Ar protocol

The Clinical Institute Withdrawal Assessment for Alcohol, Revised (CIWA-Ar) is a validated 10-item nursing assessment tool used to quantify alcohol withdrawal severity and guide symptom-triggered benzodiazepine therapy. Items include: nausea/vomiting, tremor, paroxysmal sweats, anxiety, agitation, tactile disturbances, visual disturbances, auditory disturbances, headache/fullness in head, and orientation/clouding of sensorium.

Scoring interpretation:

• Less than 10: Mild withdrawal; may not require pharmacotherapy, monitor closely
• 10–18: Moderate withdrawal; pharmacotherapy indicated
• 19 or higher: Severe withdrawal; aggressive treatment, consider ICU

Nurses perform serial CIWA-Ar assessments (typically every 4–8 hours, or every 1–2 hours in moderate-severe cases) and administer benzodiazepines when scores cross institutional thresholds. Symptom-triggered dosing using CIWA-Ar reduces total benzodiazepine use compared with scheduled dosing.

Wernicke-Korsakoff syndrome

Chronic alcohol use impairs thiamine (vitamin B1) absorption through direct GI mucosal damage and nutritional neglect. Thiamine deficiency leads to Wernicke encephalopathy — the classic triad of confusion, ophthalmoplegia (abnormal eye movements), and ataxia. If untreated, Wernicke encephalopathy progresses to Korsakoff syndrome, characterized by profound anterograde amnesia, confabulation, and personality changes. Korsakoff syndrome represents permanent neurological damage.

Critical nursing implication: Thiamine must be administered before dextrose-containing IV fluids. Glucose metabolism consumes remaining thiamine reserves and can precipitate or worsen Wernicke encephalopathy. Standard treatment is IV thiamine 100 mg for 3–7 days, followed by ongoing oral thiamine supplementation.

Pharmacology: alcohol use disorder

Nursing priorities: alcohol use disorder

• Seizure precautions from admission (padded side rails, oxygen and suction at bedside, IV benzodiazepine accessible)
• CIWA-Ar assessment every 4–8 hours minimum; escalate frequency if score rises
• Fall risk — ataxia, tremor, and sedation from benzodiazepines compound fall risk significantly
• Nutritional support: multivitamin, thiamine, folate, magnesium (commonly depleted)
• Fluid and electrolyte monitoring: hypomagnesemia lowers seizure threshold
• Therapeutic communication: non-judgmental, collaborative, motivating without lecturing

Opioid use disorder

DSM-5 criteria

Opioid use disorder uses the same 11-symptom framework as other SUDs, with severity classified as mild (2–3), moderate (4–5), or severe (6 or more). The specifier “in a controlled environment” or “on maintenance therapy” is added when applicable. Tolerance and withdrawal symptoms do not count toward the diagnosis in patients receiving opioids solely under medical supervision.

Intoxication versus withdrawal: mirror images

Opioid intoxication and withdrawal produce opposite clinical pictures. This is one of the most NCLEX-tested concepts in substance use disorders nursing.

COWS score

The Clinical Opiate Withdrawal Scale (COWS) is an 11-item validated tool used to objectively quantify opioid withdrawal severity. It is completed by a clinician or nurse in approximately two minutes and guides decisions about buprenorphine induction timing. The 11 items are: resting pulse rate, GI upset, sweating, tremor, restlessness, yawning, pupil size, anxiety or irritability, bone and joint aches, gooseflesh, and runny nose or tearing.

Severity classification:

• 5–12: Mild withdrawal
• 13–24: Moderate withdrawal
• 25–36: Moderately severe withdrawal
• 36 or higher: Severe withdrawal

A COWS score of at least 8–12 is typically required before initiating buprenorphine to prevent precipitated withdrawal — the sudden, intensely uncomfortable withdrawal syndrome that occurs when buprenorphine displaces a full agonist from receptors when the patient is not yet in sufficient withdrawal.

Naloxone (Narcan)

Naloxone is a competitive opioid receptor antagonist that rapidly reverses opioid intoxication. It has no agonist activity at any receptor — it simply displaces opioids. Key pharmacokinetics: onset 2–5 minutes IV/IM/intranasal; duration 30–90 minutes.

Critical nursing point: Naloxone has a shorter duration of action than most opioids. A patient who is reversed and appears stable can slip back into respiratory depression after naloxone wears off. Reassessment every 15–30 minutes and repeat dosing are often required. The prescriber should always be notified after naloxone administration, and observation for at least 4 hours is standard.

Dosing: IV/IM 0.4–2 mg; may repeat every 2–3 minutes to a maximum of 10 mg. Intranasal formulations (Narcan 4 mg/0.1 mL) are standard for community use.

Naloxone education before discharge: Nurses should provide take-home naloxone kits and training to patients with OUD and their family members as a harm reduction intervention before every discharge.

Medication-assisted treatment

Nursing priorities: opioid use disorder

• Airway first — in overdose: position, stimulate, oxygen, call for naloxone. Bag-valve-mask ventilation if apneic.
• Continuous respiratory monitoring: pulse oximetry, respiratory rate q15–30 min post-naloxone
• Non-stigmatizing pain management: patients on MAT still experience pain; do not withhold analgesia. Consult addiction medicine for guidance.
• COWS monitoring during active withdrawal
• Naloxone education and discharge planning for every patient with OUD

Stimulant use disorder

Cocaine and methamphetamine: overlapping but distinct

Both cocaine and methamphetamine produce catecholamine excess (dopamine, norepinephrine, serotonin) through different mechanisms. Cocaine blocks reuptake transporters and has a short half-life (30–90 minutes), producing intense but brief euphoria. Methamphetamine additionally triggers active release of dopamine from presynaptic terminals and has a longer half-life (10–12 hours), producing a more prolonged stimulant state.

Intoxication presentation

Both agents produce a sympathomimetic toxidrome:

• Hypertension and tachycardia (risk of MI, hemorrhagic stroke, aortic dissection with cocaine)
• Hyperthermia — can be severe and life-threatening with methamphetamine
• Agitation, paranoia, and psychosis (more common and prolonged with methamphetamine)
• Diaphoresis, mydriasis, tremor
• Seizures (cocaine lowers seizure threshold)

Methamphetamine psychosis can be clinically indistinguishable from schizophrenia — prominent paranoid delusions, auditory hallucinations, and disorganized behavior. It typically resolves within days to weeks of abstinence, though a subset of patients has prolonged psychosis.

Withdrawal: the crash

Stimulant withdrawal is not medically dangerous, but it is clinically significant. The “crash” that follows heavy stimulant use involves:

• Profound hypersomnia (sleeping 16–20 hours)
• Hyperphagia
• Dysphoria, anhedonia, depression (dopamine depletion)
• Fatigue, psychomotor retardation
• Intense craving

There is currently no FDA-approved pharmacotherapy for stimulant use disorder. Treatment relies on psychosocial interventions — contingency management programs have the strongest evidence base (SAMHSA, 2020). Cognitive behavioral therapy and motivational enhancement therapy are also effective.

Nursing priorities: stimulant use disorder

• Cardiovascular monitoring — 12-lead ECG, continuous telemetry if significant hypertension or tachycardia
• Cooling measures for hyperthermia: fans, cooling blankets, IV fluids; do not use antipyretics (fever is not from infection)
• Seizure precautions during intoxication
• Benzodiazepines for acute agitation (first-line for stimulant-induced agitation)
• Psychiatric support during withdrawal: screen for suicidality — the dysphoric crash period is high-risk

Sedative, hypnotic, and anxiolytic use disorder

Why this withdrawal kills

Sedatives (benzodiazepines and barbiturates) act on GABA-A receptors — the same mechanism as alcohol. Withdrawal from physical dependence follows the same pathophysiology as alcohol withdrawal: GABAergic inhibitory tone is lost, producing CNS hyperexcitability. The result is identical to severe alcohol withdrawal: anxiety, tremor, seizures, and potentially delirium.

The cardinal rule: never abruptly discontinue benzodiazepines in a physically dependent patient. Abrupt cessation can cause refractory seizures and death. This applies to patients taking prescribed benzodiazepines for legitimate indications who have developed physiological dependence — not only to those with SUD.

Cross-tolerance

Alcohol and benzodiazepines share the GABA-A receptor mechanism and are cross-tolerant. A patient in alcohol withdrawal can be treated with benzodiazepines. A patient in benzodiazepine withdrawal can, in principle, be managed with alcohol (though this is not clinical practice) or more practically with a long-acting benzodiazepine taper. This cross-tolerance also means that combining alcohol with benzodiazepines produces additive CNS and respiratory depression — a common cause of overdose death.

Management approach

Management of benzodiazepine or barbiturate withdrawal requires a structured taper, typically using a long-acting benzodiazepine (diazepam or chlordiazepoxide) to allow smooth blood level decline. The taper may extend over weeks to months depending on the degree and duration of dependence. Phenobarbital is used in some protocols, particularly for barbiturate dependence or when benzodiazepine diversion is a concern.

Nursing priorities: sedative withdrawal

• Seizure precautions throughout the taper period
• Monitor taper compliance — missed doses increase seizure risk
• Assess for concurrent alcohol use (additive withdrawal risk)
• Vital sign monitoring: escalating tachycardia and hypertension are warning signs of inadequate taper or impending DTs-equivalent syndrome
• Patient education: explain that physical dependence can develop with therapeutic use; stopping must always be supervised

Cross-cutting nursing interventions

Motivational interviewing

Motivational interviewing (MI) is an evidence-based, person-centered counseling style developed to enhance motivation for behavior change. The four core principles are: express empathy, develop discrepancy, roll with resistance, and support self-efficacy. NCLEX specifically tests that the therapeutic response in MI is non-confrontational — nurses do not argue, challenge, or pressure. They use open-ended questions, reflective listening, and affirmations.

Examples of MI-consistent responses:

• “It sounds like you have mixed feelings about cutting back — can you tell me more about that?”
• “What would you like your life to look like in a year from now?”

SBIRT: Screening, Brief Intervention, and Referral to Treatment

SBIRT is a structured, evidence-based public health approach endorsed by SAMHSA. The three components are:

1. Screen — use a validated tool (CAGE, AUDIT, DAST-10) to identify risk level
2. Brief intervention — a 5–15 minute motivational conversation for risky use
3. Referral to treatment — connect patients meeting SUD criteria to appropriate care

SBIRT is designed to be delivered by nurses and other clinicians in primary care and general hospital settings, not only in specialty addiction settings.

Harm reduction

Harm reduction accepts that not all patients with SUD will achieve immediate abstinence and prioritizes reducing the harms of ongoing use. Evidence-based harm reduction strategies include: needle exchange programs, naloxone distribution, fentanyl test strips, supervised consumption sites, and low-barrier MAT access. Harm reduction is not a permissive stance on drug use — it is a pragmatic public health approach with strong outcome evidence.

Anti-stigma documentation

Language in nursing documentation and communication affects patient care. Research demonstrates that clinicians use more punitive approaches with patients described using stigmatizing language.

Dual diagnosis

Co-occurring SUD and psychiatric disorders are the rule, not the exception. Over 50% of patients with SUD have a co-occurring mental health disorder (SAMHSA, 2023). The most common pairings are: AUD with depression and anxiety, stimulant use disorder with bipolar disorder and psychosis, and opioid use disorder with PTSD and depression. Both conditions must be treated concurrently — treating only the SUD while ignoring the psychiatric disorder, or vice versa, leads to relapse and poor outcomes. See the depression nursing reference and schizophrenia reference for psychiatric series coverage.

NCLEX high-yield tips

1. Alcohol withdrawal: priority action The priority nursing action for a patient admitted and at risk for alcohol withdrawal is to initiate CIWA-Ar assessment, establish IV access, place the patient on seizure precautions, and ensure benzodiazepines are available. Thiamine must be given before any IV dextrose.

2. Delirium tremens vs. alcoholic hallucinosis Alcoholic hallucinosis (12–24 hours) involves hallucinations with intact orientation and is dangerous but manageable. Delirium tremens (48–96 hours) involves severe autonomic instability, disorientation, and hyperthermia — it is potentially fatal and requires ICU monitoring. Do not confuse the two.

3. Opioid overdose: naloxone is not enough Naloxone reverses opioid intoxication but has a shorter duration of action than most opioids. Always reassess the patient 30–60 minutes after naloxone administration. The priority is always airway and respiratory support — naloxone does not work instantly, and the patient may need bag-valve-mask ventilation first.

4. CAGE screening — positive score A score of 2 or higher on the CAGE questionnaire is a positive screen. It does not diagnose AUD — it warrants a comprehensive assessment. The Eye-Opener question (morning drink) is the single most specific indicator of physical dependence.

5. Benzodiazepine taper: never abrupt If a patient reports taking benzodiazepines daily for months and wants to stop, abrupt discontinuation is dangerous. Always taper. This is a frequent NCLEX clinical judgment scenario.

6. Motivational interviewing: never confront The correct NCLEX response in an MI scenario is always the non-confrontational option. The nurse should not tell the patient their drinking is a problem, argue about their readiness to change, or lecture. Instead: reflect, explore ambivalence, affirm autonomy.

Related resources in this series

• Anxiety disorders nursing reference: GAD, panic, PTSD, OCD
• Depression nursing care: major depressive disorder reference
• Bipolar disorder nursing reference
• Schizophrenia nursing reference