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19 Cards in this Set
- Front
- Back
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What toxin may cause parkinsonian symptoms?
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MPTP
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Which pathway is most effected in the parkinson's disease?
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loss of nigrostriatal dopamine neurons
- leads to loss of dopaminergic innervation of the basal ganglia |
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What are the four dopminergic pathways?
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1. – Nigrostriatal
2. – Mesolimbic 3. – Mesocortical 4. – Tuberoinfundibular- involved in endocrine function |
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Primary strategy for therapy of parkinson's
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Replace or mimic dopamine focusing mostly on the D2 receptors, using L-Dopa (crosses BBB) (aka Levodopa)
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Secondary strategies for therapy of Parkinson's
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Anticholinergics
Amantadine |
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Which Dopamine receptor may mediate neuroprotective effects
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D3 receptors may mediate neuroprotective effects
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Name the pharmacologic effect of L-Dopa (levodopa)
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Motor- reverse rigidity, tremor, bradykinesia and reduced facial expression
Psychic- may improve mental funciton, sense of well being |
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S/E of L-dopa (levodopa)
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GI- N/V due to stiumlation of the chemoreceptor trigger zone
Cardiovascular- Orthostatic Hypotension, arrhythmia, tachy Other- decreased prolactin secretion Mydriasis, sweating, sleep disturbances, brownish body fluids |
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Long term S/E of L-dopa (levodopa)
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1. Motor- fluctuations in efficacy- wearing off "on-off"
2. Neurological- abnormal involuntary movements "dyskinetic/hyperkinetic" (80% of patients taking L-Dopa for 3 yrs) 3. Psychic- hallucination, paranoia, mania, anxiety, depression 4. Neuroendocrine- hypersexuality |
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L-dopa
1. Route of Administration 2. Absorption 3. Peak levels 4. T1/2 5. Metabolism and excretion |
1. Oral
2. Dependent on GI transit time 3. 1/2 to 2 hrs after 4. 1-3 hrs 5. 95% decarboxylated in periphery and excreted in urine |
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What is similar to L-dopa drug?
Why and how is it used? |
Carbidopa blocks AADC in periphery and increases L-dopa to brain (allows you to use less L-dopa)
- used with L-dopa in single pill (Sinemet) |
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Monoamine Oxidase (MAO)-B Inhibitors:
a. names b. MOA c. clinical use? |
a. selegeline, rasagiine
b. blocks catabolism of dopamine and inhibits MAO-A c. adjunct to L-Dopa (increases efficacy, decreases L-Dopa dose) |
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Catechol-O-methyl transferase (COMT) inhibitors
a. names b. MOA c. usage |
1.a. Tocapone- more potent and longer acting but hepatotoxic
b. entacapone- peripheral only (used more) 2. COMT inhibitor blocks catabolism of dopamine and L-Dopa 3. Adjunct to L-Dopa |
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Drug interactions for all therapies designed to increase dopamine concentrations?
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MAD-P
1. MAO inh- cause HTN crisis, esp MAO-A inh 2. Anticholinergics- descrease GI motility and decreased absorption 3. Dopamine antagonists and depleteing agents (antipsychotics, reserpine) 4. Pyridoxine (B6)- increases L-Dopa metabolism |
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Contraindications of L-Dopa
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AC-MB
1. Abrupt discontinuation 2. Closed angle glaucoma- due to mydriasis S/E 3. Melanoma 4. Breast- feeding |
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Use of L-dopa cautioned with?
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1. psychosis
2. cardiac diseases 3. peptic ulcer 4. open-angle glaucoma (for well controlled intraocular pressure) |
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What three dopamine agonist drugs also have D3 activity?
Which one has d1,2,3 activity and is given how? |
RPR
Ropinerole Pramipexole Rotigotine- d1-3- transdermal |
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Describe the action of the anticholingergics for parkonsin's and S/E
Names? |
1. block actions of striatal cholinergic interneurons
2. constiptation, urinary hesitance, mental confusion, hallucinations 3. Trihexyphenidyl, benztropine |
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Describe the following for Amatadine...
a. MOA b. Use c. S/E |
a. unknown- has some NMDA activity, may release dopamine, prophylaxis of influenza A
b. monotherapy or adjunct to L-Dopa c. similar to dopamine agonists, livedo reticularis, peripheral edema, and HA caution in seizures |
