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Initial Treatment of Idiopathic Parkinson’s Disease. Sandra Derghazarian August 2013. Treatment in PD. Complex because of Motor and non-motor features Disease is progressive Both early and late side effects. Goals of treatment in PD. Prevention of disease progression
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Initial Treatment of Idiopathic Parkinson’s Disease Sandra Derghazarian August 2013
Treatment in PD • Complex because of • Motor and non-motor features • Disease is progressive • Both early and late side effects
Goals of treatment in PD • Prevention of disease progression • Symptomatic treatment of motor symptoms • Management of motor complications • Wearing off/motor fluctuations • Dyskinesias • Symptomatic treatment of non-motor symptoms
Prevention of disease progression • “Neuroprotectionis an unmet need in Parkinson’s disease and no drug can be recommended yet for this purpose in practice.”
Canadian PD Guidelines 2012 • Following should not be used for neuroprotection • Vitamin E • Following should only be used as neuroprotection in context of clinical trials • Coenzyme Q10 • Dopamine agonists • MAO B inhibitors • Insufficient evidence to make recommendations for: • Amantadine • Thalamotomy • No evidence on L-dopa for neuroprotection Canadian PD Practice Guidelines
Motor symptoms • Symptoms that are being targeted by medications • Tremor • Rigidity • Bradykinesia • Gait/postural instability
What to take into account? • Know that no single medication is recommended for initial treatment • Remember goals • Reduce motor symptoms • Improve QOL • Avoid side effects Canadian PD Practice Guidelines
What to take into account? • Consider following factors • Symptom severity • Ability/desire to continue to work • Patient preference • May have fears that meds will cause deterioration • There is NO evidence to suggest this • In fact, L-Dopa may spare dopaminergic neurons Canadian PD Practice Guidelines
What are the options? “It is not possible to identify a universal first-choice drug for early PD.” Canadian PD Practice Guidelines
Levodopa • Remains the most effective for motor symptoms • Converted into dopamine • Always combined with either • Carbidopa (Sinemet) or • Benserazide (Prolopa) • They prevent peripheral decarboxylation avoid peripheral side effects of dopamine
Levodopa • L-dopa/carbidopa formulations • Regular (Sinemet R) • Usually use tablets of 100/25 • L-dopa = 100mg, Carbidopa = 25mg • Can break tablets if necessary • Sustained–release (Sinemet CR) • 100/25 or 200/50 • Not used in early treatment • 25-30% less bioavailable than Sinemet R • Remember to adjust dose!
Levodopa • How to start? • No guidelines • Usually 1 tab (100/25) potid • Should see considerable improvement • Beware of undertreating • If no effect likely not idiopathic PD
Levodopa Side-Effects • Early side effects – most common • Peripheral • Nausea, orthostatic hypotension • If severe –> Domperidone 10 mg tab • Central • Somnolence, confusion, hallucinations • Punting – repetitivepurposelessbehavior • Dopamine dysregulation syndrome – “addiction” to dopamine • Latesideeffects • Motor complications
Motor complications • What are motor fluctuations/off time? • Periods of alteration of symptom control • On/off time – initially predictable, later unpredictable • What are dyskinesias? • Drug-induced involuntary movements that include chorea and dystonia • Risk factors for development • Younger age at onset of PD, severity, higher L-dopa dose and longer disease duration
Levodopa • Try to keep dose at lowest effective possible to help avoid motor complication • No evidence that sustained-release form reduces motor complications • No evidence that entocapone delays motor complications Canadian PD Practice Guidelines
Levodopa - Recommendations • May be used as a symptomatic treatment for early PD • Dose should be kept as low as possible to maintain good function, in order to reduce development of motor complications • Modified-release levodopa should not be used to delay onset of motor complications in early PD Canadian PD Practice Guidelines
What are the options? “It is not possible to identify a universal first-choice drug for early PD.” Canadian PD Practice Guidelines
Dopamine Agonists • Stimulate dopamine receptors directly • Do not need to be converted • 2nd most potent for control of motor symptoms after L-dopa • Can be used with success in early PD • Titrate slowly to effective dose • Less risk of fluctuations but higher risk of side-effects Canadian PD Practice Guidelines
Dopamine Agonists • Ergot agonists • Bromocriptine (only one available in Canada) • Non-ergot agonists • Pramipexole (Mirapex) • Ropinirole (Requip) • [Rotigotine (patch, Neupro)] Canadian PD Practice Guidelines
Ergot Dopamine Agonists • Bromocriptine • Risk of pleuropulmonary and cardiac valve fibrosis • ESR, renal function, cardiac echo and CXR before starting and q-yearly • Risk of erythromelalgia • Because of complications and need for monitoring, rarelyused • If possible, switch to a non-ergot DA-agonist Canadian PD Practice Guidelines
Non-Ergot Agonists • Principle of start low, go slow • Pramipexole (Mirapex) • Titrate to 0.5mg potid over 3 weeks • E.g. 0.125 tid x 1 wk, 0.25 tid x 1 week, then 0.5 tid • Maintenance dose: 0.5 – 1.5 mg potid • Ropinirole (Requip) • Titrate to 2-3 mg potid over 6-9 weeks • Start at 0.25 tid, 0.5 tid, 0.75 tid, 1 tid, 1.25 tid etc
Non-Ergot Agonists • Clinical effect • Moderate • Of long duration (don’t notice wearing off) • Side effects • Nausea • Can treat with domperidone • Somnolence (“sleep attacks”) • Hallucinations • Behavioral changes • Peripheral edema
Behavioral Complications • Behavioral changes with DA-agonists– overall 13% • Gambling (50%) • Hypersexuality (40%) • Excessive spending (10%) • Management • ASK about symptoms – patients will not offer • Reduce dose or discontinue
DA-Agonists Recommendations • Dopamine agonists may be used as a symptomatic treatment in early PD • Titrated to a clinically efficacious dose • If side effects prevent this use another agonist or drug from another class • If use an ergot-derived dopamine agonist • Minimum of RFTs, ESR, and chest X-ray before starting treatment, and annually thereafter. • Given monitoring required with ergot-DA agonists, non-ergot agonist preferred Canadian PD Practice Guidelines
What are the options? “It is not possible to identify a universal first-choice drug for early PD.” Canadian PD Practice Guidelines
Monoamine Oxidase (MAO) • Group of enzymes involved in monoamine metabolism • Dopamine, serotonin, norepinephrine • Two enzyme subtypes • A and B • In basal ganglia 80% is MAO-B • MAOI and the “cheese reaction” • Hypertensive crisis if eat foods rich in tyramine • Does not happen with selective MAO-B inhibitors
MAO-B Inhibitors • Selective MAO-B inhibitors • Selegiline • Rasagiline • Selegiline • Start at 5mg daily • Increase to 5mg bid (maximum dose) • Rasagiline • Start at 0.5mg daily • Increase to 1mg daily (maximum dose)
MAO-B Inhibitors • Clinical effects • Moderate but definite • Long duration • No evidence of neuroprotection • Side effects • Nausea • Confusion • Headache
MAO-B Inhibitors - Recommendations • May be used as a treatment for people with early PD Canadian PD Practice Guidelines
What are the options? “It is not possible to identify a universal first-choice drug for early PD.” Canadian PD Practice Guidelines
Amantadine • Used in PD for over 40 years • AntiparkinsonianMoA not fully known • Partial NMDA receptor antagonist • Partial dopamine agonist
Amantadine - Use • Dose • 100 mg po daily to qid • Clinical effect • Modest for motor symptoms • Side effects • Livedoreticularis, leg edema, • Same side effect profile as dopamine agonists • Generally well-tolerated
Amantadine - Recommendations • May be used as treatment in early PD but should not be drug of first choice Canadian PD Practice Guidelines
What are the options? “It is not possible to identify a universal first-choice drug for early PD.” Canadian PD Practice Guidelines
Anticholinergics • Mechanism of Action in PD • Not clearly known • Degeneration of DA-ergicnigrostriatal neurons imbalance between striatal dopamine and Ach • Anticholinergics help counteract the imbalance • Use in PD • Typically for tremor-predominant young patients • Options • Benztropine, Ethopropazine, Procyclidine, Trihexyphenidyl
Anticholinergics • Main ones (start low, go slow): • Trihexyphenidyl (Artane) • Start 0.5-1mg bid, increase to 2mg tid • Benztropine (Cogentin) • Start 0.5-1 mg bid, increase to 2mg bid • Side effects • Confusion, hallucinations, blurry vision, increased intraocular pressure, dry mouth, urinary retention, constipation
Anticholinergics • May be used in symptomatic treatment • Typically in young patients with early PD and severe tremor • Should not be drug of first choice due to limited efficacy and side-effect profile Canadian PD Practice Guidelines
Motor Symptoms Later in PD • Levodopa remains the most effective • Over years, duration of benefit decreases • Patients feel “wearing off” before next dose • Eventually unpredictable on/off, freezing • Also, start to develop dyskinesias • As per recommendations, it is not possible to identify a universal first-choice adjuvant therapy for late PD Canadian PD Practice Guidelines
What are the options? Canadian PD Practice Guidelines
COMT Inhibitors • Entocapone • Blocks key enzyme responsible for breaking down levodopa before it reaches the brain • (Tolcapone • Not used due to hepatotoxicity ) • Improves duration of response to levodopa • Hence its usefulness in wearing off • Adds 1-2 hours of on-time/day
Entocapone (Comtan) • How to start • 1 tab of 200 mg with each dose of L-dopa • Will increase peak levodopa • often recommend 30% reduction in levodopa • practically difficult - often cannot • Side effects • Same as increasing Sinemet • Increased dyskinesias possible • Stalevo (L-dopa, carbidopa, entocapone) • 50 Ldopa/12.5 carbidopa/200 mg entacapone • Advantage is convenience
Motor Complications - Recommendations • To reduce off time • Entocapone and rasagiline should be offered • Pramipexole and ropinirole should be considered • Sustained-release L-dopa may be used but should not be first choice • To reduce dyskinesias • Amantadine may be considered Canadian PD Practice Guidelines
Two Words on Surgery • DBS of the STN may be considered to • Improve motor function • Reduce dyskinesias • Reduce medication usage • Candidates for bilateral GPi stimulation • Motor complications refractory to med mgmnt • Healthy, no significant comorbidity • L-dopa responsive • No psychiatric problems Canadian PD Practice Guidelines
Two Words on Surgery • No evidence to state whether GPi or STN is preferred target of DBS • DBS of thalamus may be considered • Patients with predominantly severe disabling tremor • STN DBS cannot be performed Canadian PD Practice Guidelines
Non-motor symptomsNote: I didn’t update these based on the canadian guidelines. All from AAN 2006 guidelines.
Non-motor symptoms • “Non-motor symptoms dominate the clinical picture of advanced Parkinson’s disease and contribute to severe disability, impaired quality of life, and shortened life expectancy”