What is Medical Cannabis (Cannabis Based Medical Products)
What is Medical Cannabis? What is it used to treat?
Medical cannabis, also known as Cannabis Based Products for Medicinal use (CBPMs), are medications derived from the cannabis plant. They contain cannabidiol (CBD) and/or tetrahydrocannabinol (THC) — the psychoactive component of cannabis. In the UK, medical cannabis has been legal since 2018 and is used to treat a range of conditions including psychological, neurological, and chronic pain disorders, as well as for palliative and end-of-life care. For a detailed list of eligible conditions, please refer to the eligibility section on this website.
What’s the eligibility criteria?
Since CBPMs are unlicensed, patients must demonstrate unmet clinical needs, meaning their condition has not improved with conventional treatments. Due to the psychoactive nature of cannabis, patients with certain conditions listed in the exclusion criteria will not be eligible for CBPMs. These patients are advised to consult their NHS consultants for alternative treatments. Patients seeking CBPMs must be over 18 years of age and may request a second opinion if they do not have any contraindications listed below.
Exclusion Criteria?
Like all medications, CBPMs is not advisable to use if you struggle from one of the following: –
- Unstable high blood pressure
- History of psychosis
- Schizophrenia
- Unstable heart conditions (within the last 6+ months)
- Pregnancy or breastfeeding
What are the side effects of medical cannabis?
Common side effects of CBMPs include:
- Drowsiness
- Confusion
- Imbalance
- Euphoria
- Diarrhea
- Dry mouth
- Anxiety and/or depression
- Heart palpitations
- Psychological dependence
- Tolerance
- Cannabis hyperemesis syndrome (CHS)
Possible adverse reactions include:
- Headaches
- Migraines
- Nausea
- Vomiting
- Diarrhea
If you experience adverse reactions, report your symptoms to the MHRA via the Yellow Card (mhra.gov.uk) scheme and inform your clinic to ensure the medication is not prescribed to you again in the future.
Cannabis dependence:
Cannabis dependence, or cannabis use disorder, can occur with any form of cannabis use, including medical cannabis. Signs of psychological dependence include:
- Using more medication than prescribed or more frequently
- Withdrawal symptoms
- Increased tolerance requiring larger doses
- Repeated unsuccessful attempts to control or stop use
- Physical or psychological issues related to use (e.g., respiratory problems, mood swings)
- Missing appointments or work to use cannabis
- Craving for non-prescribed purposes
If you exhibit any of these signs, contact your prescriber for appropriate management.
Cannabis Hyperemesis Syndrome (CHS)
CHS can occur in individuals using high doses of cannabis over a prolonged period, including medical cannabis. Symptoms include:
- Intense nausea and vomiting
- Projectile vomiting (up to 5 times an hour)
- Extreme diarrhea
- Lack of appetite
- Weight loss
If you experience these symptoms, reduce or stop use and urgently contact your prescriber. If symptoms are severe, seek immediate medical attention to avoid dehydration.
Monitoring BP / Warfin prescription
Medical cannabis can cause heart palpitations. Patients with a history of high blood pressure or heart conditions, especially those on warfarin, should be cautious as cannabis can interact with liver enzymes affecting other medications. Work closely with your GP and healthcare professionals to monitor your heart condition.
Regular blood pressure monitoring is advised:
- Low: 90/60 or below – Inform GP and clinic, seek medical attention if unwell
- Normal: 90/60 – 140/90 – Continue monitoring, update clinic at follow-up appointments
- Raised: 141/91 – 179/119 – Monitor and inform GP and clinic
- High: 180/120 or more – Significant risk, needs urgent review – update GP and clinic