By Pat Anson, PNN Editor

Very low doses of inhaled THC – the psychoactive ingredient in cannabis – can significantly reduce pain levels in chronic pain patients, according to a small study conducted in Israel.

The concept of “microdosing” cannabis isn’t new, but this was the first clinical study to demonstrate its effectiveness in temporarily relieving pain. The study was sponsored by Syqe Medical, an Israeli medical technology company that makes an inhaler designed to deliver microdoses of cannabis and other drugs.

The study involved 27 patients living with neuropathy, radiculopathy, phantom limb pain or Complex Regional Pain Syndrome (CRPS), who self-reported pain levels of at least 6 on a zero to 10 pain scale. Participants were randomly assigned to three groups that inhaled either a placebo or two different microdoses of THC.  

The most effective dose to relieve pain was just 500 micrograms of THC, inhaled 3-4 times per day. Participants reported a 2 to 3 point reduction in their pain levels for 150 minutes.  

A typical cannabis patient might consume 150,000 micrograms of THC per day – about 75 times more than the highest dose used in the study. Researchers say their findings, published in the European Journal of Pain, suggest that pain patients can benefit from dramatically lower doses.

"We can conclude from the study results that low doses of cannabis may provide desirable effects while avoiding cognitive debilitations, significantly contributing to daily functioning, quality of life, and safety of the patient,” said lead researcher Elon Eisenberg, PhD, Director of the Multidisciplinary Pain Relief Unit at Rambam Health Care Campus in northern Israel.

“The doses given in this study, being so low, mandate very high precision in the treatment modality. This precision is unique to the Syqe drug delivery technology, enabling cannabis dosing at pharmaceutical standards."

There were side effects from inhaling microdoses of THC. About 20% of patients reported feeling “high” or experienced dizziness, sleepiness, nausea, cough or dry mouth. But researchers said there was “no evidence of consistent impairment” in any of the participants.

The risk of impairment from THC is one reason researchers and cannabis companies have largely focused on the medical benefits of cannabidiol (CBD), a compound also found in marijuana. CBD is not psychoactive, while THC can make people impaired – at least in high doses.

"This study is the first to show that human sensitivity to THC is significantly greater than previously assumed, indicating that if we can treat patients with much higher precision, lower quantities of drug will be needed, resulting in fewer side effects and an overall more effective treatment,” said Perry Davidson, CEO of Syqe Medical.

“The Syqe drug delivery technology is also applicable to opioids and other compounds that, while potentially effective, are notoriously associated with dangerous side effects. The introduction of a tool to prescribe medications at such low doses with such high resolution may allow us to achieve treatment outcomes that previously were not possible."

In addition to cannabis, the company is also exploring the use of its inhaler to deliver other drugs for treating pain, sleep, anxiety and cancer. The Syqe inhaler is sold in Israel by Teva Pharmaceuticals. Approval is also being sought to begin sales in Europe, Canada and Australia. Syqe is planning to submit a medical device application to the Food and Drug Administration in the United States.