Marijuana & Synthetic Cannabinoids

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)

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

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.

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