Patient case (clinical description): A 47-year-old woman comes to the office complaining of pain in the calf and knee when she bends down. The pain limits her activity. Her medical history is significant for osteoarthritis, for which she uses nonsteroidal anti-inflammatory drugs (NSAIDs) for the past two years. She is living with her husband and has 3 children. She doesn't smoke but drinks alcohol occasionally. Her vital signs are normal. On physical examination, there is a small effusion in the right knee. The effusion grew a little larger and she developed a tender swelling in the popliteal fossa and calf. Both the pain and swelling worsened as she bent and straightened her knee.

Patient's own account: I'm a 47-year-old woman, married with 3 kids. I don't smoke and I drink occasionally. I went to the doctor because of pain in my calf and knee when I was bending down. This has been limiting my daily activities. I have been diagnosed with osteoarthritis for which I have taken anti-inflammatory drugs for the past 2 years. The doctor saw a small fluid buildup in my right knee. This buildup became a bit bigger and I have a swollen calf. The pain is worse when I bend and straighten my knee.

Clinical trial: Efficacy of Cannabidiol in Knee Osteoarthritis

Eligibility criteria:
Inclusion Criteria:

        Patient must be willing and able to give informed consent for participation in the study

          -  Age 18-80 years

          -  Knee Pain

          -  WOMAC Pain Subscale ≥ 5 during screening

          -  Mean Visual Analogue Scale (VAS) ≥ 5 during 1 week of screening.

          -  Fulfilment of the clinical criteria of the American College of Rheumatology for knee
             OA 13

          -  X-ray or MRI confirmation of knee osteoarthritis

        All medications or interventions for pain due to knee osteoarthritis must have been stable
        for two weeks prior to screening and patient is willing to maintain a stable regimen
        throughout the study.

        Exclusion Criteria:

        Exclusion Criteria:

          -  Current mood disorder (dysthymia, bipolar mood disorder)

          -  Major Depression > 12 months (Beck Depression Inventory Score ≥ 18)

          -  History of a psychoactive substance use disorder within the preceding 12 months

          -  Major coexisting medical illness (e.g. severe heart failure, pulmonary hypertension,
             renal insufficiency)

          -  Glaucoma

          -  Acute myocardial infarction

          -  Uncontrolled hypertension

          -  History of convulsion

          -  Pregnancy; women of childbearing age will be required to use contraceptives during the
             duration of the study. Furthermore a pregnancy test will be performed prior to the
             beginning of the study and once a month during the study period.

          -  Breast feeding

          -  Participation in a clinical trial in the 3 weeks preceding the study

          -  Allergy to study medication

          -  Recent intra-articular corticosteroid or hyaluronic acid injection in the knee joint.
             Patients must be willing to abstain from such interventions during the entire study

          -  Use of the following medication:

               -  opioids except for tramadol,

               -  benzodiazepines other than indicated at low doses for sleep disorders

               -  NSAID

               -  Corticosteroids

          -  Impaired kidney function (Creatinine > 1.5mg/dl)

          -  Patient has significantly impaired hepatic function defined as any of the following:

               -  Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) >5 × upper
                  limit of normal (ULN).

               -  ALT or AST >3 × ULN and (total bilirubin [TBL] >2 × ULN or international
                  normalized ratio [INR] >1.5).

               -  ALT or AST >3 × ULN with the presence of fatigue, nausea, vomiting, right upper
                  quadrant pain or tenderness, fever, rash,and/or eosinophilia (>5%).

          -  Patient is currently using or has in the past used recreational or medicinal cannabis
             or synthetic cannabinoid based medications within 3 months prior to study entry

          -  Patient is unwilling to abstain from using recreational or medicinal cannabis, or
             synthetic cannabinoid based medications during the study

          -  Patients who are not able to understand the study measures and are not able to
             complete pain assessment forms.
No condition on gender to be admitted to the trial.
No healthy subjects accepted to join the trial.
Subject must be at least 18 Years old.
Subject must be at most 80 Years

Eligibility (NLI label): Entailment