Marijuana & Synthetic Cannabinoids

Key Features

• The dried leaves and flowers of the Cannabis plant contain the psychoactive cannabinoid, delta-9-tetrahydrocannabinal (THC), which binds to endogenous cannabinoid receptors

• Toxicity is dose dependent but varies significantly by individual, prior experience, and degree of tolerance

• Synthetic cannabinoids ("Spice", "K2", "Black Mamba") are laboratory designed analogs of THC

• Onset of symptoms after smoking is usually rapid (minutes) with a duration of effect of approximately 2 hours

• Symptoms may be delayed after ingestion and can result in prolonged intoxication (up to 8 hours)

Clinical Findings

• Mild intoxication may result in

  • Euphoria

  • Palpitations

  • Heightened sensory awareness

  • Altered time perception

  • Sedation

• More severe intoxication may result in

  • Anxiety

  • Visual hallucinations

  • Acute paranoid psychosis

• Physical findings include

  • Tachycardia

  • Orthostatic hypotension

  • Conjunctival injection

  • Incoordination

  • Slurred speech

  • Ataxia

• Chronic heavy marijuana use is associated with the cannabinoid hyperemesis syndrome, which is characterized by

  • Recurrent nausea

  • Abdominal pain

  • Vomiting

• Synthetic cannabinoids have become increasingly popular and are associated with a variety of adverse side effects including

  • Seizures

  • Kidney dysfunction

  • Serious neuropsychiatric symptoms

Diagnosis

• Clinical history of marijuana use

• Blood testing is available to detect presence of the psychoactive cannabinoid, delta-9-tetrahydrocannabinal (THC):

  • High levels indicate recent use

  • Low levels may persist for hours or days

• Urine testing is available for non-psychoactive marijuana metabolites, most commonly, tetrahydrocannabinol carboxylic acid (THC-COOH): Urine test detection of THC-COOH varies from days to weeks after use, long after any psychoactive effect has passed

  • Actual detection times for THC-COOH in urine depends on marijuana dose (use), frequency of use, and individual metabolism

    • With single use, THC-COOH can typically be detected for ~3 days

    • With moderate use (4 times weekly), for ~5 days

    • With heavy (daily) use, for ~10 days

    • With long-term heavy use, for ~30 days.

Treatment

• Consider activated charcoal early after ingestion of large quantities

• There is no specific antidote currently available

• Treat anxiety and paranoia with simple reassurance and placement into a calming environment

• Benzodiazepines such as lorazepam or diazepam may be used for more severe behavioral and psychomotor symptoms

• Hypotension and sinus tachycardia should be treated with intravenous fluids

• Topical capsaicin and haloperidol have been used with variable success for the treatment of acute vomiting in patients with cannabinoid hyperemesis syndrome