Table 2 Drugs treating Alzheimer’s and Parkinson’s disease that have passed phase 3 clinical trials

Acetylcholinesterase inhibitors (AChE)

Aricept^® (donepezil)

Eisai Co. Ltd and Pfizer

AChE inhibitors avoid acetylcholine breakdown, restoring and improving the neurotransmitter activity

Diarrhea, nausea, and vomiting

[107]

Exelon^® Patch (rivastigmine)

Novartis Pharmaceuticals Corporation

Razadyne™ (galantamine)

Johnson and Johnson

Human immunoglobulin gamma 1 (IgG1) monoclonal antibody targeting Aβ

LEQEMBI™ (lecanemab)

Biogen

Binds to soluble Aβ protofibrils to prevent Aβ plaques

Amyloid Related Imaging Abnormalities (ARIA), flu-like symptoms, nausea, vomiting and variations in blood pressure

[108,109,110]

Aduhelm™ (aducanumab)

Biogen

Binds to Aβ plaques in the brain

ARIA-edema, ARIA-hemosiderin deposition (ARIA-H) microhemorrhage and headache

[95, 111]

Glycogen synthase kinase 3 (GSK3β) inhibitor to restore gut microbiome

ANAVEX 2–73 (blarcamesine)

Anavex Life Science Corp

Sigma-1 receptor activator, involved in enhancing neuroplasticity and neural cells homeostasis

Dizziness, headache

[112, 113]

Dopamine replacement

Levodopa

AbbVie Inc

Catecholamine precursor converted to dopamine in the brain by DOPA decarboxylase, with cofactor vitamin B6

Levodopa-induced dyskinesias

[69, 114, 115]

Agonists of the D₁- and D₂-like dopamine receptors

APO-go^® (apomorphine)

Britannia Pharmaceuticals

Aporphine alkaloid from morphine acidification able to bind D1- and D2-like receptors, and serotonergic, adrenergic receptors

Nausea, somnolence and hypotonia

[116]