Which of the following medication in the treatment of Parkinson's disease is an NMDA antagonist?
(B) Amantadine # N-Methyl-d-aspartate (NMDA) glutamate receptors are a class of excitatory amino acid receptors, which have several important functions in the motor circuits of the basal ganglia, and are viewed as important targets for the development of new drugs to prevent or treat Parkinson's disease (PD). NMDA receptors are ligand-gated ion channels, which composed of multiple subunits, and each has distinct cellular and regional patterns of expression. Amantadine is a NMDA receptor Antagonist that is used in early Parkinson's disease to help tremor. In recent years, amantadine has also been found useful in reducing dyskinesia that occur with dopamine medication. Amantadine is well-tolerated, but its side effects include dry mouth, constipation, bladder problems, ankle swelling and skin rash.# COMT inhibitors such as Entacapone and Tolcapone represent the newest class of Parkinson's medications. These agents have no direct effect on PD symptoms but instead, are used to prolong the effect of levodopa by blocking its metabolism. COMT inhibitors are useful primarily to help with problem of wearing-off (effect of levodopa becomes short-lived).# Dopamine agonists: These are drugs that stimulate the parts of the human brain influenced by dopamine. In effect, the brain is tricked into thinking it is receiving the dopamine it needs. Dopamine agonists are not as potent as Carbidopa/Levodopa. These are less likely to cause dyskinesia and can be taken alone or in combination with medications containing levodopa. Two most commonly prescribed oral pill agonists are Pramipexole and Ropinirole.# MAO-B inhibitors -- Selegiline blocks an enzyme in the brain thereby breaks down levodopa. These drugs have a modest effect in suppressing the symptoms of Parkinson's.
Entacapone
Amantadine
Ropinirole
Selegiline
Miscellaneous