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Summary
Cannabis-induced disorders include intoxication, withdrawal, cannabinoid hyperemesis syndrome, and other cannabis-related psychiatric and medical conditions. Causative agents include various preparations made from the cannabis plant, cannabinoid extracts, and synthetic cannabinoids that are consumed by smoking, vapor inhalation, and/or oral ingestion. Clinical features of cannabis intoxication include positive neuropsychiatric effects such as euphoria and relaxation, negative neuropsychiatric effects such as anxiety, perceptual disturbances, and cognitive dysfunction, and physiologic effects including increased appetite and changes in blood pressure. Symptoms of cannabis withdrawal manifest shortly following cessation of prolonged heavy use and include irritability, anxiety, and depression. Treatment of cannabis intoxication and withdrawal is mainly supportive. Cannabis hyperemesis syndrome can occur with heavy daily use, manifests with cyclic episodes of abdominal, pain, nausea, and vomiting, and resolves with abstinence from cannabis. Acute episodes are treated with antiemetics, IV fluids, and other supportive measures.
See “Cannabis use disorder” for information on the related substance use disorder.
Overview
Substances [2][3]
There are a variety of preparations that may be consumed by smoking, vapor inhalation, and/or oral ingestion.
- Whole-plant cannabis (street names: marijuana, weed, grass, pot, ganja): dried leaves and/or buds of the cannabis plant
- Hashish (street names: hash, dab, wax, budder): the resin of the cannabis plant, either in solid or oil form
- Cannabinoid-based products: commercially manufactured products containing tetrahydrocannabinol (THC) and/or cannabidiol (CBD)
- Medical cannabis: whole-plant cannabis (“medical marijuana”) or cannabinoids (e.g., dronabinol) used for medical indications (e.g., cancer pain, nausea, vomiting, poor appetite, glaucoma)
- Synthetic cannabinoids: synthesized cannabinoid receptor-binding substances that mimic the effect of THC [4]
DroNABINOl is an example of a medical canNABINOid.
Mechanisms of action [3][5]
Despite extensive research, the mechanisms of action of cannabinoids are still not fully understood.
- Tetrahydrocannabinol (THC): main psychoactive component
- Cannabidiol (CBD): main nonpsychoactive component
Overview of cannabis-induced disorders
- Substance-induced disorders
-
Cannabis-induced psychiatric disorders [6]
- Cannabis-induced psychotic disorder [2][7]
- Cannabis-induced anxiety disorder
- Cannabis-induced sleep disorder
-
Cannabis-induced medical disorders [3][7]
- Cannabinoid hyperemesis syndrome
- Pulmonary problems (e.g., wheezing, shortness of breath)
- Immunosuppression [8]
- Hormonal imbalances and reduced fertility [9]
- Acute myocardial infarction [10][11]
Cannabis intoxication
Clinical features [2][3][12]
The clinical features of cannabis use vary depending on the type of substance and preparation, CBD-to-THC ratio, THC dose, route of ingestion, and user comorbidities. [5][13]
Neuropsychiatric effects of cannabis
-
Positive neuropsychiatric effects
- Euphoric mood, joviality
- Calming and relaxation
- Increased awareness of the senses
-
Negative neuropsychiatric effects
- Decreased attention, disorganized thought
- Distorted sense of time
- Impairments in concentration, reaction time, coordination, judgment, and/or memory
- Depression, anxiety; , agitation, panic
- Perceptual disturbances; and other psychotic symptoms
- Social detachment
Cannabis preparations with a high CBD-to-THC ratio are less likely to induce adverse psychiatric effects than those with a low CBD-to-THC ratio. [5][13]
Physiologic effects of cannabis
- Tachycardia, tachypnea, tremor, arrhythmia
- Increased or decreased blood pressure and/or orthostatic hypotension
- Conjunctival injection, mydriasis, nystagmus
- Increased appetite
- Urinary retention
The effects of oral ingestion of THC may be delayed and unpredictable. [4]
Massive oral ingestion of cannabis products and use of synthetic cannabinoids have been associated with severe agitation, CNS depression, and seizures. [4]
Diagnosis
Approach
- Rule out life-threatening causes of altered mental status.
- If relevant, evaluate for and initiate management of acute psychosis.
- Use DSM criteria to establish the diagnosis.
- Consider urine drug screening if history of cannabis exposure is in doubt.
DSM-V diagnostic criteria [6]
Both criteria must be fulfilled during or shortly after cannabis consumption and not be attributable to another cause.
- Significant neuropsychiatric effects of cannabis: behavioral and/or psychological changes such as euphoria, anxiety, or social withdrawal
- At least two of the following within two hours of cannabis consumption:
- Tachycardia
- Conjunctival injection (red eyes)
- Increased appetite
- Dry mouth
Urine drug screening [4]
- Rarely helpful, as results may be falsely positive for acute intoxication [4]
- May be considered for the evaluation of suspected inadvertent cannabis exposure or altered mental status of unknown cause
- Does not detect most synthetic cannabinoids
Exposure to efavirenz, NSAIDs, pantoprazole, promethazine, or hemp can cause false positive results on urine drug screening. [3]
Treatment [2][4]
Treatment of cannabis intoxication is primarily supportive. Ensure patient safety, provide reassurance, and enable patients to rest in a quiet environment.
-
Severe CNS intoxication
- Follow the ABCDE approach in poisoning.
- Manage acute seizures, if necessary.
-
Significant agitation: See also “Management of the agitated or violent patient.”
- Identify potential for violence and use deescalation techniques.
- Consider benzodiazepines for agitation or antipsychotics for agitation.
- Manage acute panic attacks, if necessary.
- Treat acute psychosis, if necessary.
Use of activated charcoal following oral ingestion of cannabis products is not recommended, as the risks are considered to outweigh potential benefits. [3]
Disposition [4]
Disposition is determined on an individual basis, depending on symptoms and severity:
- Severe CNS intoxication: Admit to the ICU.
-
Acute psychosis
- Consider admission for further care and psychiatry consult (if available) [2]
- See “Disposition” in “Management of acute psychosis.”
- Children with significant symptoms: Consider admission for 24 hours of observation. [4]
- All other patients: Observe in the emergency department until signs of intoxication resolve.
Consider using the SBIRT approach to guide further counseling and treatment.
Cannabis withdrawal
Cannabis withdrawal develops within hours to days of cessation of regular use and may persist for weeks. Manifestations and symptom severity are highly variable. [2][3]
DSM-V diagnostic criteria [6]
Both criteria must be fulfilled and not be attributable to another cause.
- ≥ 3 of the following features occurring within ∼ 1 week following cessation of prolonged heavy cannabis use: [6]
- Clinically significant distress or functional impairment resulting from the above features.
Rule out potentially life-threatening withdrawal syndromes (e.g., alcohol withdrawal, benzodiazepine withdrawal), as symptoms of cannabis withdrawal are not specific. [14]
Management [14]
- Provide outpatient psychosocial support and counseling on substance use disorders.
- Symptomatic management as needed (e.g., management of acute panic attacks, benzodiazepines for agitation)
- Consider referring patients with polysubstance use and/or significant comorbidities to a supervised or inpatient withdrawal management setting.
Cannabinoid hyperemesis syndrome
Background [15][16]
- Definition: a functional nausea and vomiting syndrome associated with long-term cannabis use
- Pathophysiology: not entirely understood [15]
-
Risk factors [15]
- Male sex
- Age < 50 years
- Long-term daily cannabis use
Clinical features [15][17]
- Episodes of abdominal pain, nausea, and vomiting [17]
- Cyclic occurrence: acute onset of episodes lasting ≤ 1 week, with asymptomatic periods between
- Symptoms are relieved by hot showers or baths.
- Occurrence resolves with prolonged sustained cessation of cannabis use.
Diagnosis [16][17]
- Clinical diagnosis based on typical clinical features in chronic heavy cannabis users
- Consider using the Rome IV diagnostic criteria for functional nausea and vomiting disorders.
- Evaluate for alternative diagnoses if any red flags for abdominal pain or red flags for nausea and vomiting are present.
- See also “Diagnostic workup of nausea and vomiting.”
Management [4][17][18]
Supportive care for acute episodes
Acute management focuses on symptomatic relief and treatment of complications of intractable vomiting.
- Administer antiemetics; see “Overview of antiemetics” for agents and dosages.
- Consider capsaicin cream 0.075% applied to the abdomen or back. [15]
- Hot showers or baths may offer further symptom relief.
- Provide IV fluid resuscitation, electrolyte repletion, and/or management of acute kidney injury as indicated.
- See also “Management of nausea and vomiting.”
Long-term treatment
Cannabis hyperemesis syndrome resolves with complete cessation of cannabis use.
- Educate the patient about the etiology of their symptoms to encourage cessation.
- Consider referral to counseling for cannabis use disorder and abstinence support.
- Consider referring patients with polysubstance use and/or significant comorbidities to a supervised or inpatient withdrawal management setting.
Related One-Minute Telegram
- One-Minute Telegram 95-2024-2/3: Cannabis: a menace to heart health?
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