Aim: Glioblastoma is a heterogeneous lethal disease, regulated by a stem-cell hierarchy and the neurotransmitter microenvironment. The identification of chemotherapies targeting individual cancer stem cells is a clinical need. Methodology: A robotic workstation was programmed to perform a drug concentration to cell-growth analysis on an in vitro model of glioblastoma stem cells (GSCs). Mode-of-action analysis of the selected top substance was performed with manual repetition assays and acquisition of further parameters. Results: We identified 22 therapeutic potential substances. Three suggested a repurpose potential of neurotransmitter signal-modulating agents to target GSCs, out of which the Parkinson's therapeutic trihexyphenidyl was most effective. Manual repetition assays and initial mode of action characterization revealed suppression of cell proliferation, cell cycle and survival. Conclusion: Anti-neurotransmitter signaling directed therapy has potential to target GSCs. We established a drug testing facility that is able to define a mid-scale chemo responsome of in vitro cancer models, possibly also suitable for other cell systems.