Table 2 Routes of administration: compare and contrast
From: Priming primary care providers to engage in evidence-based discussions about cannabis with patients
Routes | Smoking | Vaporization (“vaping”) | Oral/edibles | Topical |
|---|---|---|---|---|
Notes | Combustion of dried cannabis flower using several methods: cigarettes (joints, spliffs), pipes, water pipes (bongs) | Vaporizer is used to heat dried flower or concentrated extract (oil, resin) and the resultant vapor is inhaled | Variety of edibles available; often dose/single serving is a fraction of the product (i.e.—one part of a cookie or brownie) | Many forms available: creams, ointments, patches, poultices, oils |
Pharmacology | Rapid onset and peak so one can gauge effect and titrate dosing | Rapid onset and peak similar to smoking; no smoke; less toxicant exposure than smoking | No inhalation; broad range of products; slower onset action | None of the pulmonary effects associated with inhalation; probably much less intoxicating |
Cautions | Bronchial irritation; cough; sputum; production contains carcinogens; potential for adverse effects on lung function with heavy use over many years | Substantially higher blood THC concentrations achieved at a given dose than with smoking; higher risk of adverse effects in novice users; long term lung safety is unknown; need for potentially costly equipment; risk of potentially life-threatening pulmonary illness | Onset and peak are delayed, and effects can last many hours which makes it more difficult to titrate dose; oral metabolite of THC (11-OH-THC) may have fourfold more powerful psychoactive effect risk of overdose; caution especially in novice users | Very little is known about topical preparations; unknown systemic absorption; rapidly expanding topical CBD market is completely unregulated |