[The new Parkinson's disease drugs].

The purpose of the new drugs for Parkinson's disease is control of the long-term levodopa treatment syndromes, especially wearing-off phenomenon and dyskinesia. Therefore, they show long T1/2. Most of them are classified into dopamine agonists. Others are monoamine oxidase B inhibitor and cathecole-o-methyltransferase inhibitor. Marketed dopamine agonists are bromocriptine, pergolide, talipexole, and cabergoline in Japan. Except talipexole, they are all ergot alkaloid derivatives. Their affinity for dopamine receptor is D2 group, and their T1/2 are longer than levodopa. Bromocriptine is an oldest dopamine agonist. Other 3 drugs and bromocriptine had made each other double blinded cross over trial previously. The result of double blinded studies show that their efficacy for PD treatment were equal, 40-50% patients with PD. However, in clinical usage, some difference is observed as described below. Efficacy of pergolide is strong compared with bromocriptine; however, pergolide is easy to arise dyskinesia. Talipexole is strong in the hypnosis effect. As for cabergoline, it takes long time to show medical effect, so that it is expected to control wearing-off phenomenon. Monoamine oxidase B inhibitor, Selegiline, is useful as an economizer effect to levodopa. As for the cathechole-o-methyltransferase inhibitor (COMT-I) will be make double-blinded trial in future. The efficacy for PD treatment of COMT-I is prolonged levodopa effect for PD, so that wearing-off phenomenon will be controlled. To use these drugs successfully is important with the treatment of PD. In the future, the development of the cause therapy in addition to the systematic therapy is wanted.