Chronic Administration of Cannabidiol to Healthy Volunteers and Epileptic Patients

Abstract

In phase 1 of the study, 3 mg/kg daily of cannabidiol (CBD) was given for 30 days to 8 healthy human volunteers. Another 8 volunteers received the same number of identical capsules containing glucose as placebo in a double-blind setting. Neurological and physical examinations, blood and urine analysis, ECG and EEG were performed at weekly intervals. In phase 2 of the study, 15 patients suffering from secondary generalized epilepsy with temporal focus were randomly divided into two groups. Each patient received, in a double-blind procedure, 200-300 mg daily of CBD or placebo. The drugs were administered for as long as 4½ months. Clinical and laboratory examinations, EEG and ECG were performed at 15- or 30-day intervals. Throughout the experiment the patients continued to take the antiepileptic drugs prescribed before the experiment, although these drugs no longer controlled the signs of the disease. All patients and volunteers tolerated CBD very well and no signs of toxicity or serious side effects were detected on examination. 4 of the 8 CBD subjects remained almost free of convulsive crises throughout the experiment and 3 other patients demonstrated partial improvement in their clinical condition. CBD was ineffective in 1 patient. The clinical condition of 7 placebo patients remained unchanged whereas the condition of 1 patient clearly improved. The potential use of CBD as an antiepileptic drug and its possible potentiating effect on other antiepileptic drugs are discussed.

Inhibition of an equilibrative nucleoside transporter by cannabidiol: A mechanism of cannabinoid immunosuppression

“…Nucleoside transporter inhibitors are also intriguing as adjunct therapy in cancer patients to potentiate the effectiveness of antifolate drugs (34). CBD is already known to be well tolerated in humans (35), which has previously been a problem for other nucleoside inhibitor drugs (36,37). However, in daily use of CBD or THC, there is a chance for adenosine receptor desensitization; chronic consumption of ethanol, another adenosine transporter inhibitor, results in cell tolerance to adenosine through heterologous desensitization of receptors (38).…”

Cannabidiol: from an inactive cannabinoid to a drug with wide spectrum of action

“…Only one of the eight patients getting CBD showed no improvement, while among the patients who received the placebo, 1 improved and 7 remained unchanged. 38 In a less successful study, no significant improvement in seizure frequency was observed among 12 epileptic patients who received 200-300 mg of cannabidiol per day, in addition to standard antiepileptic drugs. 39 No further clinical trials with CBD have been published since then.…”

Cannabinoids and Epilepsy

“…Two of these studies demonstrated a partial antiseizure effect of CBD [261,262], while 2 showed no significant effect [263,264]. However, all 4 studies included significant limitations, including low study sizes, insufficient blinding or randomization, or incomplete data sets.…”