Alcohol does not actually affect the efficacy of Parkinson’s medicines, but many people with Parkinson’s choose to avoid alcohol, probably because they feel that alcohol impairs their motor control. From a purely chemical perspective, L-dopa is compatible with small amounts of alcohol, whilst drinking alcohol is generally discouraged during treatment with dopamine agonists and amantadine. This is because alcohol affects the brain and can exacerbate side effects from the medicines, such as tiredness and confusion.
Dag Nyholm