Antiparkinson agents (dopaminergic)
Dopaminergic antiparkinson drugs restore dopamine signaling in the brain, either by supplying dopamine's building block or by acting like dopamine. Carbidopa-levodopa is the most effective treatment for the slowness, stiffness, and tremor of Parkinson's disease. Nausea, dizziness on standing, involuntary movements, and hallucinations are common, and benefit can wear off between doses after years of use. They should not be stopped suddenly, because that can cause a dangerous reaction resembling neuroleptic malignant syndrome.