Cannabis as Inhaler Treats Neuropathy Says New Study

Posted On August 20, 2014

In a new study published in the Journal of Pain and Palliative Care Pharmacotherapy.

ABSTRACT

Chronic neuropathic pain is often refractory to standard pharmacological treatments. Although growing evidence supports the use of inhaled cannabis for neuropathic pain, the lack of standard inhaled dosing plays a major obstacle in cannabis becoming a “main stream” pharmacological treatment for neuropathic pain. The objective of this study was to explore the pharmacokinetics, safety, tolerability, efficacy, and ease of use of a novel portable thermal-metered-dose inhaler (tMDI) for cannabis in a cohort of eight patients suffering from chronic neuropathic pain and on a stable analgesic regimen including medicinal cannabis. In a single-dose, open-label study, patients inhaled a single 15.1 ± 0.1 mg dose of cannabis using the Syqe Inhaler device. Blood samples for Δ⁹-tetrahydrocannabinol (THC) and 11-hydroxy-Δ⁹-THC were taken at baseline and up to 120 minutes. Pain intensity (0–10 VAS), adverse events, and satisfaction score were monitored following the inhalation. A uniform pharmacokinetic profile was exhibited across all participants (Δ⁹-THC plasma C_max ± SD was 38 ± 10 ng/mL, T_max ± SD was 3 ± 1 minutes, AUC_0→infinity ± SD was 607 ± 200 ng·min/mL). Higher plasma C_max increase per mg Δ⁹-THC administered (12.3 ng/mL/mg THC) and lower interindividual variability of C_max (25.3%), compared with reported alternative modes of THC delivery, were measured. A significant 45% reduction in pain intensity was noted 20 minutes post inhalation (P = .001), turning back to baseline within 90 minutes. Tolerable, lightheadedness, lasting 15–30 minutes and requiring no intervention, was the only reported adverse event. This trial suggests the potential use of the Syqe Inhaler device as a smokeless delivery system of medicinal cannabis, producing a Δ⁹-THC pharmacokinetic profile with low interindividual variation of C_max, achieving pharmaceutical standards for inhaled drugs.