UNIT 2 PD DRUGS Flashcards
What are the two major categories of PD drugs?
- Dopamine agents
- Anticholinergic agents
What is the MOA for dopamine agents?
- Promote activation of dopamine receptors
What is the MOA of anticholinergic agents?
- Prevent activation of cholinergic rectors
How is Levodopa absorbed?
Orally administered and rapidly absorbed from small intestine
What is the most important patient teaching for a patient taking levodopa?
- Food delays absorption esp. protein
- High-protein foods reduce therapeutic effects
- Teach patients not to eat protein at the same time as medication
What is important to know about neutral amino acids and levodopa?
- Neutral amino acids compete w/levodopa for intestinal absorption and for transport across the blood brain barrier
What is the MOA of Levodopa/carbidopa (Sinemet)?
- Levodopa is converted into dopamine in the CNS. Carbidopa prevents peripheral destruction of levodopa.
What are adverse effects of Levodopa/Carbidopa?
- N/V
- Dyskinesias
- Postural hypotension
- Dysrhythmias
- Psychosis
- Impulse control
- darkened sweat and urine loss
Due to the “on and off” effect of PD drugs what is important to monitor?
Blood levels
What do we need to know about dopamine agonists?
- 1st drug of choice for mild to moderate symptoms
What is the MOA of dopamine agonists?
- direct activation of dopamine receptors
- Not dependent on enzymatic conversion to be active
- Does not compete w/dietary proteins
Are dopamine agonists more or less effective than levodopa?
Less
What should we know about the Dopamine agonists Pramipexole (Mirapex)?
- Used alone in EARLY PD and w/levodopa in advanced PD
- Max benefits take several weeks
What are adverse effects of the Dopamine agonist Pramipexole (mirapex)
Monotherapy:
1. Sleep attacks***
2. Nausea
3. Dizziness
4. Daytime somnolence
5. Insomnia
6. constipation
7. Weakness
8. Hallucinations
Combined Therapy:
1. orthostatic hypotension
2. Dyskinesia
3. Increased hullucinations
What is a rare side effect of the dopamine agonist pramipexole (mirapex)
If pathologic gambling and other compulsive self-rewarding behaviors
What are some anticholinergic drugs?
- Trinexlphendyl
- Benziropine
What is the MOA of anticholinergic drugs?
- Blocks muscarinic receptors in stratum. Decreases ach. activity
What are some adverse effects of anticholinergic drugs?
- Dry mouth
- Urinary retention
- Tachycardia
- Blurred vision
- Constipation
- Photophobia
- Confusion
- Hallucinations
Never do what with PD drugs?
Stop taking abruptly
What is the MOA of COMT inhibitors?
Inhibit metabolism of levodopa in the periphery. NO direct theraputic effects on their own.
What are two examples of COMT inhibitors?
Entracapone (comtan)
Tolcapone (tasmar)
What should we know about COMT inhibitor Entacapone (comtan)
Indicated for use with levodopa
What is the MOA of Entacapone (comtan)? COMT inhibitors
- Inhibits breakdown of levadopa in the periphery
What are some adverse effects of entacapone (comtan)? COMT inhibitors
- Dyskinesia
- Orthostatic hypotension
- N/V/D
- hallucinations
- Sleep disturbances
- impulse control disorders
- Yellow and orange discoloration of urine
What should we know about tolcapone (tasmar) COMT inhibitor?
- Used only in conjunction with levodopa
- Only used if safer agents are ineffective or inappropriate
What are some adverse effects of tolcapone (tasmar) COMT inhibitors?
- Liver failure
- Dyskinesia
- Orthostatic hypotension
- Nausea
- Hallucination
- sleep disturbance
- Yellow and orange discoloration of urine
What should we know about MOA-B inhibitors?
- Considered 1st line drugs for PD
- Benefits are modest
- Combination w/levodopa can reduce the wearing off effect
What are the two MOA-b inhibitors?
- Selegline
- Rasagline
What is the MOA of selegline (eldepryl) a MOA-b inhibitor?
- inhibits breakdown of dopamine
What are adverse effects of the MOA-b inhibitor Selegline (eldpryl)?
- Insomnia
- Dry mouth
- Orthostatic hypotension
- Dizziness
- Hypertension crisis
- GI symptoms
What should we know about Rasagline (azilect)? MOA-b inhibitors
- Approved for initial therapy and for combined use with levodopa
- Benefits derived from preserving dopamine in the brain
- Avoid tyramine
What are some adverse effects of rasagline (azilect) MOA-b inhibitor?
- orthostatic hypotension
- insomnia
- irritation of buccal muscosa
- hypertensive crisis
What are other agents used to treat PD?
- Antihistamine w/anticholinergic or b-adrenergic blockers are used to manage tremors
- Antiviral agent- amantadine
- Apomorphine for hypomobility
