Anti Parkinson Drugs Flashcards
Anti cholinergic drugs bykhlasu keln b —– ma 3ada——
Hydrochloride
Mesylate
Agents that increase dopamine synthesis:
Levodopa:
Transported — to CNs
Converted to dopamine in —-
Only —-% of L dopa reaches the brain
Actively
Brain
1-3
Side effects of levodopa:
1-
2-
3-
4-
1-GI irritation and stimulation of CTZ
2-Upset stomach with nausea and vomiting
3-dyskinesia (involuntary movements)(overactivity of dopamine receptors)
4-mood changes,depression and psychosis
Agents that increase dopamine synthesis:
Dopamine:
Lower doses—-
High doses——
D1 and D2 in——
Effect of binding to D1 nad D2:
Dopamine is metabolized to —– by MAO or COMT
Vasoconstriction on alpha
Stimulates B1 cardiac receptors
Perioheral mesenteric and renal
Vasodlation
Homoooosexua(azde homovanillic acid)
How to increase levodopa in brain?
By carbidopa
Its a decarboxylase inhibitor that prevents metabolization of dopamine in the periphery so more levodopa will reach the brain (10%) and decrease the required levodopa by 5 times
T or F
Carbidopa cross the BBB
Falseee zaddy
Acts peripherally
T or F
Pyridoxine (B6) decrease the breakdown of levodopa in the oeriohery
Ghalaaaaaat
Bl aakesss
Byshtghl b 3aks l bestie carbidopa
T or f
Administration of MAO inhibitors with levodopa can lead to hypertensive crisis
Ehhhhh wley
Agents that inhibit dopamine metabolism
MAO inhibitors
1-
2-
Reversible or rrieversible inhibition?
Khaletna giline
Selegiline
Rasagiline 2nd generation
Irrreeeeeeversible
T or F
COMt trasforms normetadrenaline to VMA
And MAO converts noradrenaline to normetadrenaline
Falseeee
Reverseddd
Khaletna giline is —— administered and —- metabolized
Selegiline bser —– then will lead to —- and ——-
Rasagiline bser ——
Orally
Extensively
Amphetamine
Insomnia and vasoconstriction
1-aminoindan ma eendu vasoactive effect
T or F
Rasagilineee is selective for MAO type A
False
Type B
Agents that inhibit dopamine metabolism
COMT inhibitors
Khaletna —–
Whde m—–w whde m—-
Reversible or itreversible?
Caponeeeee
Whde Tolcapone w whde entacapone
Reversible
COMt transform dopamine to —–
Thus inhibiting it will —-
3 O methyl dopa
Prolong its effect
Inhibition of dopamine metabolism by carbidopa will lead to its metabolism by COMT to ——
This molecule will consequentially —— with —— thus—-
So entacapone is administered to ——
3 o methyl dopa
Compete with levodopa on the active tranport sites
Thus diminish its activity
Reduce methyl o dopa plasma levels by inhibiting COMt
T or F
Entacapone have longer effects than tolcapone
Entacapone acts mostly in the periphery while tolcapone acts centrally and peripherally
False
Tolcapone 8-12 hr
Entacapine 2 hr
Side effects of khalte capone:
1-
2-
Nausea
Hallucinations
Fatal hepatic failure occurs only with entacapone
Falseee
With tolcapone
Stalevo composition:
12.5 mg carbidopa
50 mg of levodopa
200 mg entacapone
Agents that increase dopamine release
1-
Mode of action
Entery and excretion
More potent or less than levodopa
Adverse effects
1-
2-
3-
4-
Amantadine (mantadix)
Increase dopamine release from neurons and inhibit dopamine reuptake
Lipophilic that may enter the brain
Unchanged renal excretion
Less potent than levodopa
1-insomnia
2-hallucination
3-depression
4-confusion and agitation
Dopamine receptor agonists:
Duration of action:
Risk of dyskinesia:
Type of receptors:
Adverse:
Longerrrr than levodopa
Less than levodopa
D2
Nausea,vomiting and hallucinations
Bromocriptine
Derivative of ——
Full agonist at ——-
At low doses used for—
High doses
Dyskinesia?
Adverse effects
Hepatic metabolism metabolism
T1/2
Vasoconstrictive ergotamine
D2
Hperprolactinemia
For parkinson
Less prominent
Same as levo plus serious cardiac problems with patients with MI
Worsening of vasospasm (alpha1 agonist)
90% undergo hepatic metabolism
3hr
Ropinirole and pramipexole
Ergot?
Receptors?
Exacerbate vasospasm?
No
D2 and D3
No
Ripinirole
—– active and metabolized by — with half life —– dyskinesia is —— frequent than in levodopa
Pramipexole
——- absorbed
Eliminated via—–
Half life
Orally
Cyp1A2
6hrs
Orally
Unchangeddddd via kidney
8-12 hrs
