Effects
The majority of antiparkinsonian drugs are directly or indirectly dopaminergic. Some are anticholinergic in action.
Indications
Parkinson’s disease, including drug-induced Parkinson’s disease in some cases.
Drug treatment
Overview of drug therapy:
1. dopaminergic agents
Levodopa is a precursor of dopamine and is considered the most important and effective pharmacotherapy for PD. Combining it with peripheral decarboxylase inhibitors prevents the formation of dopamine from levodopa in the periphery:
- Levodopa + benserazide (Madopar) Detailed information.
- Levodopa + carbidopa (Sinemet, generics).
Dopamine agonists stimulate central dopamine receptors:
- Apomorphine (solution for injection).
- Bromocriptine (Parlodel)
- Pergolide (Permax, out of commerce).
- Pramipexole (Sifrol)
- Ropinirole (Requip, Adatrel)
- Rotigotine (Neupro)
COMT inhibitors inhibit peripheral metabolism of levodopa via catechol- methyltransferase (COMT):
- Entacapone (Comtan, Stalevo).
- Opicapone (Ongentys)
- Tolcapone (Tasmar)
Monoamine oxidase inhibitors inhibit dopamine degradation by inhibiting monoamine oxidase MAO-B:
- Rasagiline (Azilect)
- Selegiline (generic, original: Jumexal).
- Safinamide (Xadago)
NMDA antagonists block strial NMDA receptors, reducing the disturbed balance between dopaminergic inhibition and glutaminergic stimulation of cholinergic neurons:
- Amantadine (Symmetrel, PK-Merz).
2. central anticholinergics
Anticholinergics inhibit central cholinergic (muscarinic) receptors and wind effective against rigor, tremor, and akinesia:
- Biperiden (akinetone -/retard).
- Procyclidine (kemadrin)
3. other active ingredients
Cholinesterase inhibitors (antidementia drugs) are used to treat Parkinson’s dementia:
- Rivastigmine (Exelon)
