Cannabis, derived from Cannabis sativa and Cannabis indica, is one of the most widely used psychoactive substances. Its active components, cannabinoids—especially delta-9-tetrahydrocannabinol (THC)—produce euphoria, altered perception, and relaxation. Although cannabis toxicity is generally not fatal, acute and chronic use can lead to clinically significant physical and psychological effects.
Active Components
- THC (Delta-9-tetrahydrocannabinol): main psychoactive agent
- CBD (Cannabidiol): non-intoxicating, modulates THC effects
- Other minor cannabinoids and terpenes
Mechanism of Action
Cannabinoids act on:
- CB1 receptors (central nervous system)
- CB2 receptors (immune system)
Activation of these receptors affects memory, motor coordination, appetite, perception, and mood.
Clinical Effects
Psychological Effects
- Euphoria
- Relaxation
- Altered perception of time
- Impaired attention and cognition
- Anxiety or panic attacks
Physical Effects
- Tachycardia
- Conjunctival injection (red eyes)
- Increased appetite
- Dry mouth
- Ataxia
Acute Toxicity
More common with high-potency THC products and edibles.
Symptoms
- Severe anxiety or panic
- Paranoia
- Nausea and vomiting
- Hallucinations (rare, high doses)
- Tachycardia and hypertension
- Drowsiness
Chronic Use Effects
- Cannabis use disorder (dependence)
- Memory impairment
- Reduced motivation (“amotivational syndrome”)
- Bronchitis in chronic smokers
- Possible association with psychosis in vulnerable individuals
Complications
- Accidents due to impaired motor skills
- Severe vomiting: cannabinoid hyperemesis syndrome (CHS)
- Cardiovascular events (rare but reported)
Diagnosis
- Clinical history and symptoms
- Urine drug screen (detects THC metabolites)
Management
1. Supportive Care
- Reassurance in a quiet environment
- Hydration
- Observation until symptoms resolve
2. Sedation
- Benzodiazepines for severe anxiety or agitation
3. Cannabinoid Hyperemesis Syndrome (CHS)
- Hot showers may give temporary relief
- IV fluids and antiemetics
- Topical capsaicin therapy
- Definitive treatment: cessation of cannabis use
4. Psychiatric Management
- Support for substance dependence
- Counseling for cannabis-related anxiety or psychotic features
Prevention & Harm Reduction
- Avoid driving after cannabis use
- Educate about potency differences (smoking vs. edibles)
- Discourage use in adolescents and individuals with mental illness
Detailed Notes:
For PDF style full-color notes, open the complete study material below:
PATH: PHARMD/ PHARMD NOTES/ PHARMD FOURTH YEAR NOTES/ CLINICAL TOXICOLOGY/ CANNABIS GROUP.