Does cannabis help in severe itching?
Neff et al.
Pruritus due to cholestatic liver disease [please see below for an explanation] can be particularly difficult to manage and frequently is intractable to a variety of medical therapies. The aim of our study is to evaluate the efficacy of delta-9-tetrahydrocannabinol (delta-9-THC) for intractable cholestatic related pruritus (ICRP) that has failed conventional (and unconventional) remedies. Three patients were evaluated for plasmapheresis [please see below for an explanation] because of ICRP. All 3 patients had previously been extensively treated with standard therapies for ICRP including: diphenhydramine, chlorpheniramine, cholestyramine, rifampicin, phenobarbital, doxepin, naltrexone, UV therapy, and topical lotions. Even multiple courses of plasmapheresis were performed without any benefit for the intractable pruritus. All patients reported significant decreases in their quality of life, including lack of sleep, depression, inability to work, and suicidal ideations.
All patients were started on 5 mg of delta-9-THC (Marinol) at bedtime. All 3 patients reported a decrease in pruritus, marked improvement in sleep, and eventually were able to return to work. Resolution of depression occurred in two of three. Side effects related to the drug include one patient experiencing a disturbance in coordination. Marinol dosage was decreased to 2.5 mg in this patient with resolution of symptoms. The duration of antipruritic effect is approximately 4-6 hrs in all three patients suggesting the need for more frequent dosing. Delta-9-tetrahydrocannabinol may be an effective alternative in patients with intractable cholestatic pruritus.
Source: Neff GW, et al. Preliminary observation with dronabinol in patients with intractable pruritus secondary to cholestatic liver disease. Am J Gastroenterol 2002 Aug;97(8):2117-9
Explanations: What are cholestatic liver disease and plasmapheresis?
The term cholestasis originally derives from Greek and literally means "a standing still of bile." This disruption of bile flow can occur in the liver cells, in the small channels that transport the bile in the liver or in larger channels that transport the bile from the liver to the gallbladder and into the bowel. Cholestasis or cholestatic liver disease may or may not result in jaundice with yellow coloured skin. It may be accompanied by severe itching.
Plasmapheresis is a method to remove certain substances from the blood plasma in a process similar to that used in an "artificial kidney," or dialysis, treatment. The procedure became known as plasmapheresis, meaning plasma separation. It is also known as plasma exchange.