Use of cannabinoids in the treatment of epilepsy
The present invention relates to the use of cannabidiol (CBD) in the treatment of patients with childhood-onset epilepsy who are concurrently taking immunosuppressant drugs. In particular the immunosuppressant drug is a calcineurin inhibitor. More particularly the immunosuppressant drug is tacrolimus. Where the CBD is used in combination with an immunosuppressant drug, caution should be taken. For example, the dose of either the CBD and/or the immunosuppressant drug may be required to be reduced. Moreover, the patient may need to be monitored for side effects of said drug-drug interaction. Preferably the CBD used is in the form of a highly purified extract of cannabis such that the CBD is present at greater than 98% of the total extract (w/w) and the other components of the extract are characterised. In particular the cannabinoid tetrahydrocannabinol (THC) has been substantially removed, to a level of not more than 0.15% (w/w) and the propyl analogue of CBD, cannabidivarin, (CBDV) is present in amounts of up to 1%. Alternatively, the CBD may be a synthetically produced CBD.
1. A method of treating childhood-onset epilepsy in a patient who is concurrently taking tacrolimus, comprising:
administering to the patient a drug substance comprising at least 98% (w/w) cannabidiol (CBD) and less than 0.15% (w/w) THC;
detecting toxic blood levels of tacrolimus or one or more associated markers; and
reducing the dose of tacrolimus to no more than 5 mg per day.
2. The method according to claim 1 , wherein the dose of CBD is lowered.
3. The method according to claim 1 , wherein the drug substance is in the form of a highly purified extract of cannabis which comprises at least 98% (w/w) CBD.
4. The method according to claim 1 , wherein the CBD is present as a synthetic compound.
5. The method according to claim 3 , wherein the extract further comprises up to 1% (w/w) CBDV.
6. The method according to claim 1 , wherein the dose of CBD is below 50 mg/kg/day.
7. The method according to claim 1 , wherein the dose of CBD is greater than 20 mg/kg/day.
8. The method according to claim 1 , wherein the childhood-onset epilepsy is: Lennox-Gastaut Syndrome; Myoclonic Absence Epilepsy; Tuberous Sclerosis Complex; Dravet Syndrome; Doose Syndrome; Jeavons Syndrome; CDKL5; Dup15q; Neuronal ceroid lipofuscinoses (NCL) or brain abnormalities.
9. The method of claim 1 , wherein the associated markers comprise serum creatine.
10. The method of claim 9 , wherein the serum creatine become toxic when the blood levels are 2.4 mg/dL or more.
11. The method of claim 1 , wherein the dose of tacrolimus is reduced by up to 10-fold.
12. The method of claim 1 , wherein the dose of tacrolimus is reduced to 0.5 mg twice per day.