PARKINSON'S DISEASE Flashcards
Try to remember how all the different Parkinson’s medications fit into schema
What do you know about Selegiline and Rasagiline?
Selegiline and Rasagiline are monoamine oxidase inhibitor - specifically to B receptors. They enter the brain and prevent the breakdown of dopamine. They also inhibit the pre- synaptic reuptake of catecholamines and enhance dopamine synthesis but blocking presynaptic dopamine auto receptors.
Generally well tolerated.
Risk of serotonin syndrome with SSRI much less than previously thought.
What do you know about Safinamide?
licensed as an add on treatment, Safinimide is a newer, more selective monoamine oxidase inhibitor. Like the older types (Seligiline and Rasagiline) it works by entering the brain and reducing the breakdown and reuptake of dopamine.
How does Madopar differ from sinemet?
Madopar = levo
What do you know about Madopar?
Madopar = Levodopa + Benserazide at a ratio of 4:1. This is the mainstay of treating Parkinson’s. Comes in immediate and controlled release forms.
Levodopa is converted to dopamine by dopa-decarboxylase. It alleviates the symptoms of Parkinson’s disease by replenishing depleted striatal dopamine.
Benserazide, a dopa-decarboxylase inhibitor, prevents the peripheral breakdown of levodopa to dopamine. This increases available levodopa in the brain and reduces peripheral adverse effects. It does not cross the blood-brain barrier.
Side effects of levodopa include nausea, Postural hypotension, drowsiness, psychosis, hallucinations, dyskinesias, rarely impulse control disorders.
Levodopa dosing: initially 50 mg 3–4 times daily, increased by 100 mg daily once or twice weekly according to response; usual maintenance dose 200mg 3-4 x per day
What do you know about Sinemet?
Sinemet = Levodopa + carbidopa. Its name means “without emesis” as the carbidopa prevents peripheral break down of levodopa and lessens side effect of nausea significantly (as lower doses of levodopa required).
Side effects are as for levodopa - nausea, Postural hypotension, drowsiness, psychosis, hallucinations, dyskinesias, rarely impulse control disorders.
Comes in immediate release, modified release and intestinal gel.
What are some things you can do to trouble shoot people not tolerating initial dosing of levodopa well and are really nauseated?
- try adding domperidone (but check QTC)
- try controlled release preparation
- try a bigger dose (sometimes the low dose of carbidopa isn’t enough to prevent peripheral conversion so paradoxically a higher dose is better tolerated)
What do you know about Pramiprexole, ropinerole and rivastigmine?
These are all dopamine agonists (non ergot). They should be used alongside levodopa to reduce levodopa dose required.
2 very important side effects to ask about are impulse control disorders and sleep attacks. Both can be dangerous. Can also cause ankle oedema.
These medications can also be addictive - When you have too much its called Dopamine dysregulation syndrome and when you don’t have enough its called DAWS - dopamine agonist withdrawal syndrome.
Pramiprexole dosing: initially 125 micrograms 3 times daily, dose doubled every 5–7 days if tolerated to 500 micrograms 3 times daily; further increased if necessary by 250 micrograms 3 times daily at weekly intervals; maximum 4.5 mg daily in 3 divided doses
What is entacapone?
Entacapone prevents the peripheral breakdown of levodopa, by inhibiting catechol-O-methyltransferase, allowing more levodopa to reach the brain.
It is used as an add on therapy to
