Stimulant Use Disorders

Stimulants 101 - The Fast Lane

• Definition: Psychoactive drugs that induce temporary improvements in mental/physical functions. Cause ↑ alertness, energy, euphoria.
• Common Examples:
  • Cocaine ("coke", "crack", "snow")
  • Amphetamines (e.g., Dextroamphetamine, Methamphetamine/"meth", MDMA/"ecstasy")
  • Methylphenidate (Ritalin)
  • Modafinil
  • Khat (Catha edulis leaves)
• Core Mechanism: Primarily potentiate catecholamines (Dopamine, Norepinephrine) by blocking reuptake or enhancing release.

⭐ Formication (tactile hallucination of insects crawling on/under skin - "cocaine bugs" or "meth mites") is a characteristic psychotic symptom of chronic stimulant use.

Neurobiology - Brain's Dopamine Rush

• Primary effect: ↑↑ Dopamine (DA) in brain's reward pathway.
• Mechanism of Action (MOA):
  • Cocaine: Blocks Dopamine Transporter (DAT), preventing DA reuptake.
  • Amphetamines: Promote DA release from presynaptic terminals & block DAT.
• Key Pathway: Mesolimbic System ("Reward Pathway").
  • Ventral Tegmental Area (VTA) projects to Nucleus Accumbens (NAc).
  • NAc activation → intense euphoria, reinforcement, "rush".
  • Prefrontal Cortex (PFC) involvement: craving, executive dysfunction.

⭐ Stimulants cause a rapid, high-magnitude DA surge in the NAc, far exceeding natural rewards, leading to powerful reinforcement properties of these drugs.

Clinical Picture - Highs, Lows, & Alerts

• Cardiovascular: MI, CVA, HTN crisis, arrhythmias.
• Neurological: Seizures, hyperthermia, psychosis.
• Withdrawal: Severe depression, suicidality.

⭐ Formication (tactile hallucination of insects under skin) is classic in chronic stimulant intoxication ("cocaine bugs").

Complications - The Toll Taker

• Cardiovascular: Myocardial infarction, arrhythmias, dilated cardiomyopathy, severe hypertension, hemorrhagic/ischemic stroke.
• Neurological: Seizures, movement disorders (e.g., choreoathetosis), persistent psychosis, significant cognitive impairment.
• Psychiatric: Worsening depression/anxiety, intense paranoia, suicidal ideation/attempts.
• Infectious (IVDU): HIV, Hepatitis B/C, infective endocarditis, cellulitis, abscesses.
• Dental: "Meth mouth": rampant caries, gingivitis, tooth loss.
• Nutritional: Severe malnutrition, cachexia, vitamin deficiencies.
• Obstetric: IUGR, placental abruption, preterm labor, neonatal abstinence syndrome.

⭐ Methamphetamine-associated cardiomyopathy (MACM) is a distinct form of dilated cardiomyopathy; early cessation offers the best chance for cardiac function recovery.

Management - Navigating Recovery

• Acute Intoxication:
  • Supportive care (ABCs).
  • Agitation/Psychosis: Benzodiazepines (e.g., Lorazepam 2-4mg IV/IM), antipsychotics (e.g., Haloperidol 5mg IM).
  • Hyperthermia: Cooling blankets, IV fluids.
  • Severe Hypertension/Tachycardia: Labetalol (cautiously), cardiac monitoring.
• Withdrawal Management:
  • Primarily supportive care.
  • Monitor for depression, anhedonia, suicidality.
  • No FDA-approved medications.
• Long-Term Relapse Prevention:
  • Psychosocial interventions are primary.
    • Cognitive Behavioral Therapy (CBT).
    • Contingency Management (CM).
  • No FDA-approved pharmacotherapy.
  • Off-label options (limited evidence): Modafinil, Bupropion.

⭐ Contingency Management (CM) shows robust efficacy in promoting abstinence in stimulant use disorders.

High‑Yield Points - ⚡ Biggest Takeaways

• Mechanism: Stimulants (cocaine, amphetamines) primarily ↑ dopamine, norepinephrine, serotonin.
• Intoxication: Presents with euphoria, agitation, mydriasis, hypertension, and characteristic formication ("cocaine bugs").
• Withdrawal: Characterized by dysphoria, profound fatigue, hypersomnia, and ↑ appetite.
• Complications: Include life-threatening MI, stroke, seizures, and nasal septal perforation with cocaine.
• Intoxication Management: Primarily benzodiazepines for agitation/seizures; antipsychotics for psychosis.
• Withdrawal Management: Supportive care; no FDA-approved medications currently exist.