5.3 Cannabis & Hallucinogen Use Disorders

5.3 Cannabis & Hallucinogen Use Disorders

Cannabinoids and other hallucinogens represent 6% of the CARN exam (approximately 9-11 items). Although these substances rarely produce fatal withdrawal, the exam tests recognition of cannabis use disorder, cannabis hyperemesis syndrome, synthetic cannabinoid toxicity, and the distinctive management of hallucinogen and dissociative intoxication.

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Cannabis Use Disorder

Delta-9-tetrahydrocannabinol (THC) is a partial agonist at cannabinoid CB1 receptors. Cannabis use disorder is diagnosed with the same 11 DSM-5-TR criteria as other substances. Roughly 3 in 10 people who use cannabis develop some degree of cannabis use disorder; risk rises sharply with adolescent-onset use (about 1 in 6) and with daily use of high-potency products.

Cannabis Withdrawal Syndrome

Abrupt cessation after sustained heavy use produces a DSM-recognized withdrawal syndrome:

• Irritability, anger, or aggression
• Anxiety and restlessness
• Sleep difficulty with strange, vivid dreams
• Decreased appetite and weight loss
• Depressed mood, headache, and physical discomfort

Onset is 24-72 hours after last use, symptoms peak at days 2-6, and the syndrome resolves over 1-2 weeks. It is uncomfortable but never life-threatening; nursing care focuses on sleep hygiene, hydration, reassurance, and craving-management skills. There is no FDA-approved medication for cannabis use disorder; motivational enhancement therapy, CBT, and contingency management are the evidence-based treatments.

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Cannabis Hyperemesis Syndrome (CHS)

CHS is a paradoxical syndrome of cyclic nausea and vomiting in patients with chronic, heavy cannabis use. Key diagnostic clues:

1. Cyclic vomiting separated by symptom-free intervals, often with morning predominance.
2. Compulsive hot bathing or showering — patients learn that hot water temporarily relieves symptoms; this behavior is a near-pathognomonic clue.
3. Standard antiemetics (ondansetron) are frequently ineffective.

Acute care includes IV fluids and electrolyte repletion; topical capsaicin applied to the abdomen and haloperidol have shown benefit. The only definitive cure is cannabis cessation, and relapse returns symptoms — the nurse's non-judgmental education about this link is the central intervention.

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Potency, Synthetic Cannabinoids, and Detection Windows

• High-potency THC concentrates ('dabs,' wax, oils exceeding 60-90% THC) are associated with acute anxiety, panic, and psychosis; epidemiological links to psychotic disorders are strongest with adolescent and high-potency use.
• Synthetic cannabinoids (K2, Spice) are full CB1 agonists far more potent than THC, producing severe agitation, seizures, psychosis, and acute kidney injury. They are not detected on standard urine drug screens.
• Urine detection windows (high-yield): THC metabolites are lipophilic and store in adipose tissue — approximately 3 days after single use, 1-2 weeks with moderate use, and several weeks (30+ days) in chronic heavy users. This is why a positive urine screen alone cannot prove recent use in a daily user.

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Approved Cannabinoid Medications (Do Not Confuse)

Distinguish illicit/high-potency cannabis from FDA-approved cannabinoid medications: dronabinol and nabilone (appetite stimulation and chemotherapy-induced nausea) and cannabidiol (Epidiolex) (specific pediatric epilepsy syndromes). None treats cannabis use disorder, and state 'medical marijuana' programs operate outside FDA approval with variable product purity.

Classic Hallucinogens: LSD, Psilocybin, Mescaline

Classic hallucinogens act as 5-HT2A serotonin receptor agonists. They produce perceptual distortions, synesthesia, and altered self-experience but no withdrawal syndrome and no physiological dependence (tolerance develops within days and resets quickly).

Managing Acute Intoxication ('Bad Trip')

1. Move the patient to a calm, quiet, low-stimulation environment with continuous supervision.
2. Provide reassurance ('talking down'): remind the patient the effects are drug-induced, temporary, and will pass.
3. Use a benzodiazepine (e.g., lorazepam) for severe agitation or panic.
4. Protect from self-harm or accidental injury; reality-test gently rather than arguing with hallucinations.

Hallucinogen Persisting Perception Disorder (HPPD) — spontaneous visual 'flashbacks' weeks to months after use — is a recognized long-term complication.

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Dissociatives (PCP, Ketamine) and MDMA

Phencyclidine (PCP) and ketamine are NMDA receptor antagonists. PCP intoxication produces a classic, testable picture:

• Vertical AND horizontal nystagmus (a hallmark clue)
• Hypertension, hyperthermia, diaphoresis
• Insensitivity to pain, bizarre or violent behavior, apparent 'superhuman' strength

Management prioritizes a quiet, dark, low-stimulation room, benzodiazepines for agitation, and avoidance of physical restraints (struggling against restraints causes rhabdomyolysis and hyperthermia). Anticipate monitoring creatine kinase, temperature, and urine output.

MDMA combines stimulant and hallucinogen effects. Life threats include hyperthermia, hyponatremia (from SIADH plus excessive water intake at dance events), and serotonin syndrome — monitor temperature and sodium, and treat hyperthermia with aggressive cooling.

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Inhalants (Brief Recognition)

Volatile solvents, nitrites, and nitrous oxide produce rapid, brief intoxication. Dangers include sudden sniffing death (fatal arrhythmia), peripheral neuropathy, and cumulative cognitive deficits. Treatment is supportive; prevention education targets adolescents, the highest-use group.