regulating dopamine levels Flashcards
the cause of AD is thought to be the degeneration of […] neurons in the […] portion of the extrapyramidal motor system.
this causes reduced dopamine levels.
dopaminergic
substantia nigra
reduced dopamine levels.
the substantia nigra is thought to be the focal point of dopaminergic neuron degeneration in AD because…..
producing dopamine requires production of free radicals.
dopaminergic neurons are highly concentrated in the substantia nigra—>high rate of ROS production.
may be concomitant with a mutation in PARKIN receptor of the mitochondria that impedes the metabolism of ROS products.
the focus of AD treatment is […] rather than curative. The objective being to restore dopaminergic/cholinergic balance in the striatum (basal ganglia).
palliative.
why cant you give patient pure dopamine to tx AD?
dopamine does not cross the BBB.
it is also an emetic, and oral ingestion would cause severe vomiting.
L-DOPA is made from […], before being converted to dopamine by […].
Dopamine can be converted to […] by Dopamine Beta-Hydroxylase.
tyrosine
DOPA decarboxylase.
noradrenaline
dopamine is broken down and metabolized by [….].
MAO (monoamine oxidase) and COMT (catecholo-methyl transferase)
[..and …] are drugs given to patients with parkisons disease in conjuction with levodopa to inhibit peripheral metabolism of levodopa into dopamine, and increase amount of levodopa that crosses the BBB.
carbidopa and benserazide
L-DOPA is an [….]. More than 90% is converted by […] into dopamine and noradrenaline in the periphery.
Only 10% of dose reaches the CNS.
amino acid isomer.
DDC (dopamine decarboxylase)
dopamine can cause [….] of symptoms in many patients, and thus its effectiveness declines over time with the continued degeneration of dopaminergic neurons.
acceleration
[……] are dopamine agonists that may be preferred in [….] patients, since it can be used as monotherapy and
bromocriptine and cabergoline
younger
entacapone is a dominergic drug that acts by inhibiting {….] metabolism of L-DOPA to 3-O-methyldopa.
COMT
selegiline is a dominergic drug that acts by inhibiting {….] metabolism/deactivation of dopamine.
—>these are advantageous to [….] inhibitors because there are fewer hypertensive crises.
Early use may decrease progression of AD because […..] production is decreased.
MAO(B)
MAO(A)
free radical
[…] is a dopaminergic agent (originally an antiviral for influenza) that enhances dopamine release, but less effective than L-DOPA and more rapid tolerance.
amantadine
muscarinic receptor antagonists can be used as an adjunct to L-DOPA with the objective of titrating the [….] effect of L-DOPA. However, these have the classic anti-muscarinic side effects of: [….]
anticholinergic
Reduced SLUD = salivation, lacrimation, urination, defecation
