Background and objective There is limited evidence about the efficacy and safety of cannabinoids in the treatment of patients with Huntington’s disease (HD). Five patients with HD were treated with nabilone, a synthetic cannabinoid, in order to alleviate therapy-resistant symptoms.
Methods All patients and caregivers were informed about the off-label use of nabilone and gave written informed consent. A Clinical Global Impression Scale (CGI) and the Unified Huntington's Disease Rating Scale (UHDRS) were applied prior, after one and four weeks to decide on the continuation of nabilone treatment.
Case reports Patient 1 is a 20-year-old male who presented with disabling tics, generalised chorea and increased irritability. He developed severe parkinsonism during therapy with amisulpiride and olanzapine. Amisulpiride was stopped and he was treated with nabilone 1 mg/d.
Patient 2 is a 48-year-old female with 10 years history of HD and chronic pain. Multiple treatment trials were ineffective. Nabilone 2 mg/d was introduced.
Patient 3 is a 62-year-old female with disabling chorea and increased irritability. She developed severe akathisia as a side effect of several antidopaminergic therapies. Treatment with nabilone 1.5 mg/d was commenced.
Patient 4 is a 46-year-old female who had parkinsonism and depression under therapy with tetrabenazine. Treatment with nabilone 3 mg/d was introduced as monotherapy.
Patient 5 is a 67-year-old female with disabling chorea and increased irritability. She developed parkinsonism during therapy with tetrabenazine. Medication was changed to 2 mg/d nabilone.
Results Transient mild sedation during titration occurred in patients 3, 4 and 5, mild non-disturbing xerostomia in patient 3. All patients reported improved symptoms as assessed by the CGI. UHDRS and Chorea-scores improved in all patients. A reduction of tics without worsening of parkinsonism with nabilone was seen in patient 1. Patient 2 reported that her pain completely subsided. Irritability substantially improved with nabilone in patients 1, 3 and 5. Moreover, tetrabenazine could be stopped in patients 3, 4 and 5. This resulted in a remission of akathisia in patient 3, in improved parkinsonism in patients 4 and 5 as well as in ameliorated mood in patient 4.
Conclusions These case series suggest that nabilone may be an effective and well tolerated adjunct to the drug treatment of HD. However, larger controlled trials are needed to confirm these preliminary open-label observations.