This handout provides a concise clinical reference for healthcare providers who need to speak knowledgeably about cannabis with patients. Print it as a quick-reference for your office.
Cannabis Basics: A Clinical Reference
Key concepts for healthcare providers
Key Cannabinoids
| Cannabinoid | Primary Effects | Clinical Notes |
|---|---|---|
| THC (Δ9-tetrahydrocannabinol) | Psychoactive, analgesic, antiemetic, appetite stimulant | Primary driver of intoxication and dependence risk. Dose-dependent anxiety effects. |
| CBD (Cannabidiol) | Anxiolytic, anti-inflammatory, anticonvulsant, non-intoxicating | FDA-approved as Epidiolex for seizures. May modulate THC effects. CYP450 inhibitor. |
| CBN (Cannabinol) | Mildly sedating, mildly psychoactive | Oxidation product of THC. Limited clinical evidence. Often marketed for sleep. |
| CBG (Cannabigerol) | Anti-inflammatory, non-intoxicating | Precursor to THC and CBD. Early research stage. Growing commercial interest. |
The Endocannabinoid System (ECS)
The ECS is an endogenous signaling system present throughout the central and peripheral nervous systems. It consists of CB1 receptors (concentrated in the brain — mood, memory, pain, appetite), CB2 receptors (primarily immune system and peripheral tissues), and endogenous ligands (anandamide and 2-AG). The ECS modulates neurotransmitter release and plays a role in homeostasis. Exogenous cannabinoids like THC act primarily on CB1 receptors, which is why chronic use leads to receptor downregulation and tolerance.
Methods of Consumption
| Method | Onset | Duration | Bioavailability | Clinical Notes |
|---|---|---|---|---|
| Inhalation (smoking/vaping) | 1–5 min | 2–4 hrs | 10–35% | Rapid titration possible. Respiratory risks with combustion. |
| Edibles | 30–120 min | 4–8 hrs | 4–12% | Delayed onset — risk of overconsumption. 11-hydroxy-THC (more potent metabolite). |
| Sublingual (tinctures) | 15–45 min | 4–6 hrs | ~20% | Easier dose control than edibles. Bypasses first-pass metabolism partially. |
| Topicals | Variable | Localized | Minimal systemic | No psychoactive effects. Used for localized pain/inflammation. |
THC:CBD Ratios
| Ratio | Profile | Typical Use |
|---|---|---|
| High THC (20:1+) | Strongly psychoactive | Pain, nausea, appetite. Higher CUD risk. |
| THC-dominant (5:1 – 10:1) | Psychoactive with some modulation | Pain, sleep. Most common dispensary products. |
| Balanced (1:1 – 2:1) | Mild psychoactivity, synergistic | Anxiety, pain. CBD may buffer THC side effects. |
| CBD-dominant (1:5 – 1:20) | Minimal to no intoxication | Anxiety, inflammation, seizures. Lower risk profile. |
Important Terminology
- Strain vs. Cultivar: "Strain" is the common term; "cultivar" is botanically correct. Neither reliably predicts effects.
- Indica / Sativa / Hybrid: Marketing categories with limited scientific basis. Chemical profile (cannabinoid and terpene content) is more predictive than plant morphology.
- Full-spectrum: Contains the full range of cannabinoids, terpenes, and other plant compounds.
- Isolate: Pure single cannabinoid (usually CBD). No entourage effect.
- Entourage effect: Theory that cannabinoids and terpenes work synergistically. Plausible but not yet rigorously established.
The endocannabinoid system plays a modulatory role in numerous physiological processes. Understanding its basic function is increasingly important for clinicians as cannabis use becomes more prevalent among patient populations.
Zou & Kumar, International Journal of Molecular Sciences, 2018
For support with quitting or cutting back on cannabis, visit our companion site CannabisDependence.org