Cannabis for arthritis and chronic pain

TL;DR

• Meta-analyses show moderate, significant reduction in chronic joint pain.
• Effect smaller than strong analgesics, but a good add-on when NSAIDs are not tolerated.
• Oral forms (oil, capsule) preferred in older adults, no smoking.
• Israeli cohort (Abuhasira 2018): 93% report improvement, most common side effect dizziness.

What does the evidence actually show?

The Cochrane and JAMA meta-analyses (Whiting 2015) pool several RCTs on chronic non-cancer pain and find an average number needed to treat of around 24 for a 30% pain reduction. For arthritis specifically fewer large RCTs exist, but observational studies and the Israeli registry cohort (Abuhasira 2018), with over 2000 patients over 65, mostly report positive subjective effects.

Limits and caution in older adults

Older populations are under-represented, much data comes from observational cohorts without placebo control. Also, the side-effect rate (dizziness, sedation, confusion) rises noticeably with age, increasing fall risk (see the Fall risk spoke). Cannabis should therefore never be a sole first-line therapy but a carefully titrated add-on.

Swiss legal framework and medical prescribing practice

Since the amendment of the law in August 2022, access to medical cannabis in Switzerland has been significantly simplified for patients with chronic pain such as osteoarthritis. Doctors can now prescribe medicinal products containing THC directly on a narcotics prescription, without having to obtain a time-consuming exceptional authorisation from the Federal Office of Public Health (FOPH). This liberalisation significantly facilitates therapeutic support in old age. Nevertheless, the legal distinction remains important: over-the-counter CBD products with a total THC content of less than one percent do not fall under the Narcotics Act, whereas higher-dose medical preparations strictly require a prescription.

However, coverage of costs by the mandatory health insurance (OKP) is still not automatically regulated in Switzerland. In most cases, those affected must submit a prior request for cost assumption to their health insurance provider, which is reviewed by the medical assessor. Reimbursement is often only granted if established standard therapies have demonstrably failed or were not tolerated due to contraindications. For older patients, this means that detailed clarification and documentation by the treating medical staff is necessary before starting therapy to avoid financial risks.

• Direct medical prescription of medical cannabis without an exceptional authorisation from the FOPH has been possible since August 2022.
• Over-the-counter CBD products must have a total THC content of less than one percent to be considered legal.
• Health insurance providers generally only cover the costs of THC preparations after a case-by-case review and prior cost assumption.
• Close medical supervision and regular check-ups by physicians are mandatory.

Dosage and the therapeutic principle of gradual titration

When using cannabinoids for pain relief in osteoarthritis in advanced age, the dosing principle of gradual titration is of central importance. Since the aging body metabolises active substances more slowly and reacts more sensitively to psychoactive effects, the dose is adjusted step by step. Treatment usually begins with a minimal dose in the evening to shift any sedative effects into the sleep phase. Only when no adverse effects occur after several days can the dose be carefully increased under medical supervision until noticeable pain relief is achieved.

This structured approach minimises the risk of acute side effects such as dizziness or confusion, which can lead to falls, particularly in older people. Since pain perception and individual tolerance vary widely, there is no standardised one-size-fits-all dose for all patients. The use of standardised oily solutions or capsules enables precise dosing in the milligram range, which would not be achievable with inhalative forms of consumption. Accurate documentation of the amount taken and pain intensity in a diary helps to optimally determine the therapeutic window.

• Initiation of therapy with a minimal dose in the evening to avoid unwanted daytime sedation.
• Gradual increase of the dose (titration) over several days or weeks to minimise risk.
• Use of standardised drops or capsules for precise dosing in the milligram range.
• Keeping a pain diary to document effects, dosage, and any side effects.

Interactions with existing medication in old age

Many seniors suffering from osteoarthritis already take various medications for concomitant diseases such as high blood pressure, diabetes, or cardiovascular complaints. When additionally taking medical cannabis, the risk of interactions must be carefully analysed. Both CBD and THC are metabolised in the liver via the cytochrome P450 enzyme system. This can cause the levels of other medications in the blood to rise or fall unpredictably, thereby strengthening or weakening the effect of these drugs.

Interactions with blood thinners, cardiac medications, and other painkillers are particularly relevant. The combination with sedative substances such as sleeping pills or strong painkillers from the opioid group can also lead to a dangerous enhancement of the depressant effect on the central nervous system. Before starting cannabis therapy, a complete medication review by the treating physician or a pharmacist is therefore essential. This is the only way to systematically minimise adverse drug reactions and ensure safe use in the context of polypharmacy.

• Metabolism of cannabinoids via the hepatic enzyme system can alter the blood concentration of other medications.
• Increased caution is advised when taking blood thinners and heart medications simultaneously.
• Risk of increased sedation when combined with opioids, antidepressants, or sleeping aids.
• Mandatory review of the entire medication list by qualified specialists before starting therapy.

Mobility and participation in Swiss road traffic

An often underestimated aspect of therapy with THC-containing preparations is the legal and practical situation in Swiss road traffic. In Switzerland, a strict zero-tolerance policy applies to THC, with a statutory limit of 1.5 micrograms of THC per litre of blood. Since this limit can be exceeded even with very low doses or even days after the last consumption, patients undergoing THC therapy are quickly deemed legally unfit to drive. This may significantly restrict the daily mobility of elderly people.

Even if cannabis has been medically prescribed, this does not automatically exempt one from criminal liability during a traffic check. Driving ability must be assessed and certified in writing on a case-by-case basis by the treating physician, although this confirmation does not guarantee absolute legal certainty in an emergency. With pure CBD preparations containing less than one percent THC, the risk of exceeding the limit is significantly lower; however, traces of THC can still be detected in the blood. Patients should definitely take this aspect into account when making their therapy decision.

• In Switzerland, a strict THC limit of 1.5 micrograms per litre of blood applies to road traffic.
• A medical prescription does not automatically protect against legal consequences during a traffic check.
• Individual driving ability must be regularly evaluated by a doctor and documented in writing.
• Even when using CBD products below the one percent limit, THC accumulation in the blood is possible.

FAQ