L-DOPA (Levodopa) is an amino acid precursor of dopamine with antiparkinsonian properties. It is a prodrug converted to dopamine by DOPA decarboxylase and can cross the blood-brain barrier. In the brain, levodopa is decarboxylated to dopamine, stimulating dopaminergic receptors and compensating for depleted endogenous dopamine in Parkinson's disease. To ensure adequate concentrations reach the central nervous system, levodopa is administered with carbidopa, a decarboxylase inhibitor that does not cross the blood-brain barrier, reducing peripheral decarboxylation and increasing CNS dopamine delivery.

Mirtazapine (6-Azamianserin) is a tetracyclic antidepressant with a somewhat unique mechanism of action. Mirtazapine therapy can be associated with transient asymptomatic elevations in serum aminotransferase levels and has been linked to rare instances of clinically apparent acute liver injury.

Clozapine N-oxide is the major metabolite of Clozapine and is blood-brain barrier permeable. Clozapine N-oxide is an agonist of DREADDs and activates the DREADD receptors hM3Dq and hM4Di. Clozapine N-oxide is also a dopamine antagonist and selective muscarinic M4 receptor agonist.

Mianserin hydrochloride (Org GB 94) is a tetracyclic compound with antidepressant properties that blocks alpha-adrenergic, histamine H1, and certain serotonin receptors; it may cause drowsiness and hematological issues.

Doxepin hydrochloride (Aponal) is a dibenzoxepin tricyclic compound. It displays a range of pharmacological actions including maintaining adrenergic innervation. Its mechanism of action is not fully understood, but it appears to block reuptake of monoaminergic neurotransmitters into presynaptic terminals. It also possesses anticholinergic activity and modulates antagonism of histamine H(1)- and H(2)-receptors.

Olanzapine (LY170053) is an atypical antipsychotic that is used currently in the treatment of schizophrenia and bipolar illness.

Citicoline (CDP-Choline) is an intermediate in the synthesis of phosphatidylcholine, a component of cell membranes. Citicoline exerts neuroprotective effects.

Octodrine (2-Amino-6-methylheptane) is primarily used as a pharmaceutical intermediate for Octamylamine; it also functions as a local anesthetic and vasoconstrictor.