TABLE 1

Commonly used pharmacological agents to treat symptoms of Parkinson disease

Adapted from Armstrong and Okun (2020) and Seppi et al. (2019).

	Symptom	Mechanism of Action	Medication	FDA-Approved Indication for PD or Off Label
Motor symptoms	Core PD symptoms	DA precursor	IR carbidopa-levodopa	FDA approved
			CR carbidopa-levodopa	FDA approved
			ER carbidopa-levodopa	FDA approved
	Core PD symptoms and motor fluctuations	Nonergot DA agonists	Pramipexole	FDA approved
			Ropinirole	FDA approved
			Rotigotine	FDA approved
		Monoamine oxidase-B inhibitors	Selegiline	FDA approved
			Rasagiline	FDA approved
			Safinamide	FDA approved
			Zonisamide	Off label
	Motor fluctuations	Catechol-O-methyltransferase inhibitors	Entacapone	FDA approved
		Catechol-O-methyltransferase inhibitors	Opicapone	FDA approved
		Adenosine A2A receptor antagonist	Istradefylline	FDA approved
	Rescue medication	Levodopa formulation	Inhaled carbidopa/levodopa	FDA approved
		Nonergot dopamine agonist	Sublingual apomorphine	FDA approved
		Nonergot dopamine agonist	Injectable apomorphine	FDA approved
	Dyskinesias	Noncompetitive NMDA receptor antagonist	IR amantadine	FDA approved
		Noncompetitive NMDA receptor antagonist	ER amantadine capsule/tablet	FDA approved
		Anticholinergics	Trihexyphenidyl	FDA approved
		Anticholinergics	Benztropine	FDA approved
Nonmotor symptoms	Cognitive changes	Acetylcholinesterase inhibitors	Rivastigmine	FDA approved
			Donepezil	Off label
			Galantamine	Off label
		NMDA receptor antagonist	Memantine	Off label
	Psychosis	D2 and 5-HT2 receptor antagonist	Quetiapine	Off label
		D2 and 5-HT2 receptor antagonist	Clozapine	Off label
		5-HT2A and 5-HT2C receptor agonist and antagonist	Pimavanserin	FDA approved
	Depression and anxiety	Tricyclic antidepressants	Nortriptyline	Off label
			Amitriptyline	Off label
			Imipramine	Off label
			Desipramine	Off label
		Selective serotonin reuptake inhibitor/serotonin norepinephrine inhibitor	Citalopram	Off label
			Escitalopram	Off label
			Sertraline	Off label
			Paroxetine	Off label
			Venlafaxine	Off label
		Levodopa formulations	Carbidopa/levodopa formulations	Off labela
		DA precursors	Pramipexole	Off labela
			Ropinirole	Off labela
			Rotigotine	Off labela
	Insomnia/sleep disorders	Melatonin receptor 1A agonist	Melatonin	Supplement
	Insomnia/sleep disorders	DA precursors	Controlled-release carbidopa/levodopa	Off labela
	Orthostatic hypotension	Fluid retention	Salt tabs	Supplement
		DA2-receptor antagonist	Domperidone	Not FDA approved
		α1-adrenergic receptor stimulator	Midodrine	Off label
		Increased Na reabsorption	Fludrocortisone	Off label
		Increased norepinephrine	Droxidopa	FDA approved
		Acetylcholinesterase inhibitor	Pyridostigmine	Off label
	Constipation	Anionic surfactant	Docusate	Off label
		Stool bulking	Fiber	Supplement
		Mixes stool fat and water	Polyethylene glycol	Off label
	Anorexia, nausea, vomiting	DA2-receptor antagonist	Domperidone	Not FDA approved
	Anorexia, nausea, vomiting	VGNA and K channel blocker, GABA receptor enhancer	Zonisamide	Off label
	Drooling	Anticholinergic	Atropine 1% ophthalmic drops under the tongue	Off label
			Glycopyrrolate	Off label
			Botulinum toxin B	FDA approved
	Urinary	Muscarinic antagonist	Solifenacin	Off label
	Urinary	β3-adrenergic agonist	Mirabegron	Off label
	Fatigue	Monoamine oxidase-B inhibitors	Rasagiline	Off labela
		DA and NE reuptake inhibitors	Methylphenidate	Off label
		DA reuptake inhibitor	Modafinil	Off label
	Pain	Nonergot dopamine agonists	Rotigotine	Off labela
	Pain	DA precursor	Carbidopa/levodopa formulations	Off labela

CR, controlled release; ER, extended release; IR, immediate release; NE, norepinephrine; VGNA, voltage-gated sodium.
^aThese medications are FDA-approved for treatment of PD, but they are often used to treat these PD-related symptoms off label.