Impulse control disorders (ICDs) (such as pathological gambling, hypersexuality, compulsive shopping …) are an increasingly recognized psychiatric complications in Parkinson's disease (PD). Therapeutic management of these disorders is important since they have an impact on patient quality of life. Dopamine agonists play a key role in the emergence of ICD.

Animal models and imaging underline the implication of opioid system in the genesis of ICD.

An opioid antagonist, the naltrexone, has been studied to treat ICDs in PD. Papay and al 2014 have found that patients treated by naltrexone showed an interesting decrease of their ICDs measured by the QUIP RScale. Nevertheless, naltrexone has shown adverse effects such as increasing hepatic liver enzymes. Nalmefene has no known hepatic adverse effects. Nalmefene is an opioid antagonist that has an antagonist action on μ and δ receptors, but also an agonist action on κ receptor. Grant and al 2006 has shown significant reduction of the severity of pathological gambling in patients treated with nalmefene.

The primary purpose is to evaluate the efficacy and the safety of nalmefene in the treatment of ICDs in PD.

In this open study, 30 patients with ICDs, will be treated with 18 mg per day of nalmefene during 3 months.

Patients will be evaluated 2 times: at inclusion visit (J0) and 3 months after (at the end of the study, +3months).

At each time, patients will have :

• a clinical and neurological evaluation
• neuropsychological tests for cognitive, depression and TCI evaluations.
• blood sample to test hepatic and renal functions
• tolerance evaluation with a list of adverse events/effects

Patients will be contacted 3 times by phone: 2 weeks after inclusion, 1 month after inclusion and 2 months after inclusion, to note the presence of adverse events.

Inclusion Criteria:

• Patient suffering of Parkinson's disease
• Male or Female aged from 18 to 80 years old
• Diagnosis of ICDs with the Ardouin Scale of Behavior in Parkinson's Disease (ASBPD) with a score of at least 2 on one of the Item of hyperdopaminergic symptoms
• No modification of the treatments for PD since 3 months
• No modification of parameters of deep brain stimulation since 6 months
• Patients who understood and signed the consent form
• Patients having a social security

Exclusion Criteria:

• Contraindication to nalmefene (Patients receiving opioid antalgics, antecedent of opioid dependence, dopamine agonist withdrawal syndrome, opioid consumption, patient receiving methadone or buprenorphine, severe hepatic failure, severe renal failure, antecedent of alcohol withdrawal, galactose intolerance, lactose deficit or glucose malabsorption, pregnant women)
• Cognitive impairment with Mini Mental Score < 26
• Psychiatric comorbidities (bipolar disease, schizophrenia)
• Patient participating in another therapeutic study