5.1 Stimulant Use Disorders: Cocaine, Amphetamines & Caffeine
Key Takeaways
- Stimulant use disorders (cocaine, amphetamines, caffeine) carry a 15% weight (22-24 items) on the official CARN blueprint, the third-largest patient-problem category after opioids and alcohol.
- Stimulant intoxication produces a sympathomimetic toxidrome (tachycardia, hypertension, hyperthermia, mydriasis, agitation); severe complications include myocardial infarction, aortic dissection, stroke, and seizures.
- Benzodiazepines are first-line for acute stimulant toxicity (agitation, hypertension, seizures); non-selective beta-blockers are traditionally avoided in acute cocaine toxicity because of unopposed alpha-adrenergic vasoconstriction.
- Stimulant withdrawal ('the crash') is not medically dangerous but carries high suicide risk from severe dysphoria and anhedonia; mandatory suicide screening is a nursing priority.
- No FDA-approved pharmacotherapy exists for stimulant use disorder; contingency management combined with cognitive behavioral therapy has the strongest evidence base.
5.1 Stimulant Use Disorders: Cocaine, Amphetamines & Caffeine
Stimulant use disorders account for 15% of the CARN examination (approximately 22-24 items) under the official ANCB blueprint, covering cocaine, amphetamine-type stimulants (including methamphetamine), and caffeine. With the proliferation of high-purity methamphetamine and stimulant-opioid co-use ('speedballing'), stimulant questions test both acute medical management and long-term behavioral treatment strategy.
Neuropharmacology of Stimulant Agents
Cocaine is a potent blocker of presynaptic reuptake transporters for dopamine (DAT), norepinephrine (NET), and serotonin (SERT). Blockade of dopamine reuptake in the mesolimbic reward pathway produces intense euphoria. Cocaine has a short elimination half-life (30-90 minutes); smoked crack cocaine reaches the brain in seconds, producing an intense, brief high that drives compulsive redosing.
Amphetamine-type stimulants (methamphetamine, amphetamine) not only block reuptake but also reverse transporter direction and disrupt vesicular monoamine storage (via VMAT), causing massive release of dopamine and norepinephrine. Methamphetamine's long half-life (8-12 hours) produces prolonged intoxication and severe neurotoxicity with chronic use. Prescription stimulants (methylphenidate, mixed amphetamine salts) are misused for performance enhancement, appetite suppression, and euphoria.
| Feature | Cocaine | Methamphetamine |
|---|---|---|
| Primary mechanism | Reuptake blockade (DAT/NET/SERT) | Reuptake blockade + transporter reversal + vesicular monoamine release |
| Elimination half-life | 30-90 minutes | 8-12 hours |
| Common routes | Intranasal powder, smoked crack, IV | Smoked ('ice'), IV, intranasal, oral |
| Typical binge pattern | Repeated redosing every 15-30 minutes | Prolonged 'runs' lasting days without sleep or food |
| Signature chronic harms | Nasal septum perforation, myocardial infarction, stroke | 'Meth mouth,' skin excoriations, cardiomyopathy, persistent psychosis |
The long methamphetamine half-life explains both its multi-day binges and its protracted withdrawal; the short cocaine half-life explains the compulsive redosing pattern that rapidly depletes money and drives high-risk behavior.
Stimulant Intoxication: The Sympathomimetic Toxidrome
Acute stimulant intoxication produces a recognizable sympathomimetic toxidrome:
| System | Clinical Findings |
|---|---|
| CNS | Euphoria, hypervigilance, severe agitation, paranoia, hallucinations (including formication with chronic methamphetamine), seizures |
| Cardiovascular | Tachycardia, hypertension, chest pain, myocardial infarction, aortic dissection, lethal dysrhythmias |
| Thermoregulatory / Other | Hyperthermia, profuse diaphoresis, mydriasis (dilated pupils), bruxism, rhabdomyolysis |
High-yield complications: Cocaine-associated chest pain and myocardial infarction can occur in young patients with no cardiac risk factors (coronary vasospasm plus increased myocardial oxygen demand). Hemorrhagic and ischemic stroke, seizures, and excited delirium are additional life threats.
Acute Nursing & Medical Management
- Benzodiazepines are first-line therapy for stimulant toxicity: lorazepam or diazepam reduce central sympathomimetic outflow, controlling agitation, hypertension, tachycardia, and seizures.
- Cocaine chest pain: continuous cardiac monitoring, 12-lead ECG, serial troponins; nitroglycerin and benzodiazepines are standard. Non-selective beta-blockers are traditionally avoided in acute cocaine toxicity because unopposed alpha-adrenergic stimulation can worsen coronary vasoconstriction and hypertension.
- Hyperthermia: aggressive external cooling; check creatine kinase and renal function for rhabdomyolysis.
- Environment: low-stimulation, quiet room; minimize prolonged physical restraint (worsens hyperthermia and rhabdomyolysis); use chemical de-escalation early.
Stimulant Withdrawal: 'The Crash'
Stimulant withdrawal is not medically life-threatening (unlike alcohol or sedative withdrawal), but it is psychiatrically high-risk. After binge cessation, patients experience:
- Profound dysphoria and anhedonia
- Fatigue with initial hypersomnia followed by insomnia
- Increased appetite
- Psychomotor retardation
- Vivid, unpleasant dreams
- Intense craving
The acute 'crash' occurs within hours of last use and lasts 1-3 days; protracted anhedonia and craving persist for weeks. Severe depression with suicidal ideation is common during the crash — the CARN nurse must perform and document suicide risk screening on every stimulant withdrawal patient.
Treatment: Behavioral Therapies Anchor Care
Critical exam fact: There is no FDA-approved medication for cocaine or methamphetamine use disorder. Agents studied off-label (bupropion, mirtazapine, topiramate, modafinil, naltrexone combinations) show modest, inconsistent benefit.
Evidence-based behavioral treatments:
- Contingency Management (CM): The strongest evidence base. Patients earn tangible, escalating reinforcers (vouchers or prize draws) for each stimulant-negative urine drug screen over structured 8-12 week programs.
- Cognitive Behavioral Therapy (CBT): Functional analysis of triggers, craving-management skills, relapse prevention.
- Matrix Model: A 16-week structured intensive outpatient framework for stimulant use disorder combining CBT, family education, contingency management, drug testing, and 12-step linkage.
Nursing care includes treating comorbid conditions (careful, monitored stimulant prescribing for true ADHD), sleep and nutritional rehabilitation, and overdose education for patients who co-use opioids ('speedball') — always pair with naloxone distribution.
Methamphetamine-Specific Findings
- 'Meth mouth': severe dental caries and tooth loss from xerostomia (dry mouth), bruxism, acidic intake, and neglected hygiene.
- Skin excoriations from formication (sensation of insects crawling under the skin) and compulsive picking.
- Dilated cardiomyopathy and pulmonary hypertension with chronic use.
- Persistent neurocognitive deficits (attention, memory, executive function) that improve slowly over months of abstinence.
Caffeine
Caffeine is the most widely used psychoactive substance in the world. The DSM-5-TR recognizes caffeine intoxication (doses typically >250 mg: restlessness, nervousness, insomnia, flushed face, gastrointestinal upset, tachycardia, rambling speech) and caffeine withdrawal (headache beginning 12-24 hours after cessation, fatigue, dysphoria, poor concentration, peaking at 1-2 days) — but caffeine is not classified as a formal substance use disorder. Clinically, warn patients that combining energy drinks with alcohol masks perceived intoxication without reducing impairment.
A 29-year-old patient is admitted with cocaine use disorder and asks the nurse which medication will be prescribed to stop their cravings. According to current evidence, what is the most accurate nursing response?
A patient arrives in the emergency department with severe agitation, blood pressure 198/112 mmHg, heart rate 132 bpm, and diaphoresis one hour after smoking methamphetamine. Which pharmacological intervention is the first-line priority?
A patient admitted to a detoxification unit stopped using cocaine 18 hours ago after a two-week binge. The patient is sleeping excessively, reports feeling hopeless and 'empty,' and has a strong craving. Which nursing assessment takes priority during this phase?