A D2 receptor agonizing agent with a 5HT1A receptor agonizing agent or a a2 adrenergic receptor agonizing agent is used to treat Parkinson's disease, ADHD or microadenoma. A a2 adrenergic receptor agonizing agent with a 5HT1A receptor agonizing agent is used to treat Parkinson's disease, ADHD or microadenoma. The D2 receptor agonizing agent can be a compound of formula (I), pergolide, bromocriptane, ropinerol or pramipexole. The 5HT1A receptor agonizing agent can be a compound of formula (I), buspirone, gepirone, ipsapirone or flexinoxan. The a2 adrenergic receptor agonizing agent can be a compound of formula (I), yohimbine or idazoxan. In formula (I) X is N or CH; Y is a group of formula (II) and Z is a group of formula (III).
The use of pyrido[1,2-a]pyrazine derivatives for the treatment of Parkinson's disease, ADHD and microadenomas