How the inhalation of cannabis works

Administration via the pulmonary route (inhalation) of cannabis can be a convenient, very rapid and efficient method of cannabinoid delivery for patients. It allows self-titration to the desired therapeutic effect.

A vaporizer medical device is used to administer pharmaceutical-quality cannabis herbal material. The rapid onset of effects of inhaled cannabinoids enable easier titration to an optimal dose based on symptom severity, tolerability and avoidance of side effects.

Bioavailability of inhaled cannabis

THC and CBD are lipophilic compounds rapidly absorbed and distributed by the lungs. The bioavailability of inhaled THC is upward of 40%. Following inhalation, THC and CBD plasma levels increase rapidly. The increase in plasma concentration of cannabinoids is dose-dependent. Peak plasma concentrations typically occur 3-10 minutes after inhalation, resulting in onset of clinical effects after about 5-10 minutes and taper off within 1-3 hours.

Pulmonary pharmacokinetics profile

THC and CBD plasma concentrations

There is low inter-subject variability in THC plasma concentrations with pulmonary administration. Pulmonary administration of THC mostly avoids first-pass metabolism. THC is converted to its active metabolite, 11-OH-THC, and further metabolism occurs later.

Reducing variability in pulmonary dosing

Administration by smoking is never advised. The use of a quality vaporizor medical device eliminates exposure to toxic pyrolytic compounds of cannabis smoke and reduces variability in administered cannabinoid content with ≤ 35 % of dose reaching the lungs. Highly functioning devices markedly reduce variability in the administered dose.

Registered medical devices like the SyqeAir Inhaler or the Volcano Medic® are now available. Other reliable, aff ordable and portable devices are required to ensure that patients have access to these devices.

Inter-patient and intra-patient variability

Inter-patient and intra-patient variability in administered dose occurs from the depth of inhalation, duration of inhalation, and breath-holding time. The quality and consistency of the cannabis herbal material used and the quality of the thermal inhalation medical device will either increase or decrease variability.

Patients with COPD and/or asthma should be monitored when using such a device as the depth of breath and breath-hold time will impact the total dose.