Table 1.

Treatment cascade of current dopaminergic substitution tools with respect to the concept of continuous dopaminergic stimulation

Drug	Step	Mode of action within the dopaminergic system	Tolerability	Main clinical relevant side effects	Efficacy
MAO-B-I	I	stabilize dopamine levels in the striatal synaptic cleft by inhibition of dopamine metabolism	+++	risk for rise of raised blood pressure and increase of liver enzymes, contraindication for simultaneous fluoxetine and fluvoxamine use, precaution with application of SSRI in general	+
NMDA-A	I	indirect dopaminergic modulation, reduce motor complications (?)	+	oedema, insomnia, hallucinations	+
DA	II	stimulate directly postsynaptic striatal receptors linked to motor symptom control	+	Orthostatic syndrome, oedema, nausea, slow titriation necessary	++
LD/DDI/COMT-I	III	precursor of dopamine, DDI and COMT-I reduce LD metabolism	+++	orthostatic syndrome, homocysteine elevation (LD/DDI alone), motor complications, diarrhea (COMT-I)	+++
infusion systems (apomorphine, LD)	IV	See DA, respectively LD line	+	Subcutaneous local inflammatory reactions	+++
DBS	V	electric stimulation of the subthalamic nuclei or globus pallidus	+	Social adjustment problems, depression, cognitive dysfunction.	+++

DBS = deep brain stimulation, MAO-B-I = MAO-B-Inhibitors, NMDA-A = NMDA-antagonist, DA = dopamine agonist, LD = levodopa, DDI = decarboxylase inhibitor, COMT-I = inhibitor of catechol-O-methyltransferase, judgement on tolerability and efficacy are based on the personal experience of the author.