<unk>  is an antitussive or cough suppressant which acts as a sigma receptor agonist.It is an analogue of dextromethorphan and dextrorphan, but lacks significant NMDA receptor antagonistic action and dissociative effects, thereby having reduced abuse potential and adverse effects in comparison.
Dimemorfan
Diprenorfin
Muzolimine
Rivastigmine
Rivastigmine 
Memantine
Valpromide
Guanabenz