Parkinsons Flashcards
Levodopa (L-DOPA)
Class: Dopamine precursor
Mech: Oral, absorbed in small bowel
Therapeutics: Given with carbidopa, first line treatment for Parkinson’s unless patient is young (want to delay as long as possible)
Tox: Hallucinations, dyskinesias, on-off phenomenon, neuroleptic malignant syndrome (NMS), psychosis possible with chronic use
Nausea, GI distress, hypotension, dizziness
Misc: Given with carbidopa, may accelerate PD progression, relatively short half-life (3 hrs)
Carbidopa
Class: Aromatic amino acid decarboxylase inhibitor
Mech: Inhibits peripheral conversion of L-DOPA to dopamine; does not cross the BBB
Therapeutics: Given with Levodopa for Parkinsons
Tox: Hallucinations, dyskinesias, on-off phenomenon, neuroleptic malignant syndrome (NMS), psychosis possible with chronic use
Nausea, GI distress, hypotension, dizziness
Misc: MAO-A inhibitors are contraindicated except MAO-B which only hits DA
Bromocriptine
Class: Ergot derivative
Mech: D2 agonist, D1 antagonist
Thera: Mild Parkinson’s; DA agonism in NMS; hyperprolactinemia
Tox: Pleural effusions, cough, SOB, pulmonary fibrosis, peripheral DA-like effects
Misc: Must be titrated slowly due to hypotension
Pergolide
Class: Ergot derivative
Mech: N/A
Thera: No longer used for Parkinson’s
Tox: Cardiac valve regurgitation, pleural effusions, cough, SOB, pulmonary fibrosis, peripheral DA-like effects
Misc: Must be titrated slowly due to hypotension
Pramipexole
Class: Non-ergot DA receptor agonist
Mech: Selective D2 agonist
Thera: Mild Parkinson’s (first-line); to delay L-DOPA treatment, usually in combination with ropinorole
Tox: More acute: psychosis, nausea/GI, edema, compulsive behavior (nucleus accumbens, D3)
Misc: Less effective with motor symptoms of PD
Ropinorole
Class: Non-ergot DA receptor agonist
Mech: Selective D2 agonist
Thera: Mild Parkinson’s, restless leg syndrome
Tox: More acute: psychosis, nasuea/GI edema, daytime sleep attacks
Misc: Less effective with motor symptoms of PD
Rotigotine
Class: Non-ergot receptor agonist
Mech: Selective D2 agonist
Thera: Mild Parkinson’s, restless leg syndrome
Tox: More acute: psychosis, nasuea/GI edema
Misc: Transdermal patch; less effective with motor symptoms of PD
Apomorphine
Class: Non-ergot DA receptor agonist
Mech: N/A
Thera: Rescue therapy for “off” periods
Tox: Psychosis, drowsiness, hypersexuality (increase erections), emesis (pre-administer trimethobenzamide or domiperidone); hypotension with serotonin receptor antagonists, peripheral DA effects
Misc: Injectable only; serotonin receptor antagonists contradicted (eg ondansetron)
Entacapone
Class: COMT inhibitor
Mech: Prevents breakdown of DA
Thera: Prolong half-life of levodopa, reduce “off time”; primarily works peripherally
Tox: Increase in dyskinesias, diarrhea, urine discoloration, DA side effects
Misc: Short-acting (2 hours)
Tolcapone
Class: COMT inhibitor
Mech: Prevents breakdown of DA
Thera: Prolong half-life of levodopa, reduce “off time” primarily works peripherally
Tox: Fatal hepatotoxicity (use only if entacapone fails), increase in dyskinesias, diarrhea (worse than entacapone), urine discoloration, DA side effects
Misc: Short-acting (2 hours)
Selegiline
Class: MAO-B inhibitor
Mech: Prevents breakdown of DA
Thera: Mild early Parkinson’s (monotherapy); may delay onset of levodopa therapy
Tox: Hypotension, GI distress, dyskinesia, psychosis, nausea, vomiting
Misc: Antidote to enviromental toxins; contraindications include: decongestants dextromethorphan, St. John’s wort, analgesics, methadone, tramadol, propoxyphene, caution with SSRIs and MAO-A inhibitors
Rasagiline
Class: MAO-B inhibitor
Mech: Prevents breakdown of DA
Thera: Mild early Parkinson’s (monotherapy); may delay onset of levodopa therapy; also as an adjunct with levodopa (reduces “off” time)
Tox: Hypotension, GI distress, dyskinesia, psychosis
Misc: contraindications include: decongestants dextromethorphan, St. John’s wort, analgesics, methadone, tramadol, propoxyphene, caution with SSRIs and MAO-A inhibitors
Benztropine
Class: Anticholinergics
Mech: N/A
Thera: Tremor and drooling in Parkinson’s and really only used if drooling is a major problem (otherwise, very bad mental symptoms)
Tox: Confusion, impaired memory, hallucinations, typical anticholinergics (dry mouth,etc)
Misc: Contraindicated in demented Parkinson’s; abrupt discontinuation exacerbates symptoms
Biperiden
Class: Anticholinergics
Mech: N/A
Thera: Tremor and drooling in Parkinson’s and really only used if drooling is a major problem (otherwise, very bad mental symptoms)
Tox: Confusion, impaired memory, hallucinations, typical anticholinergics (dry mouth,etc)
Misc: Contraindicated in demented Parkinson’s; abrupt discontinuation exacerbates symptoms
Trihexyphenidyl
Class: Anticholinergics
Mech: N/A
Thera: Tremor and drooling in Parkinson’s and really only used if drooling is a major problem (otherwise, very bad mental symptoms)
Tox: Confusion, impaired memory, hallucinations, typical anticholinergics (dry mouth,etc)
Misc: Contraindicated in demented Parkinson’s; abrupt discontinuation exacerbates symptoms
Procyclidine
Class: Anticholinergics
Mech: N/A
Thera: Tremor and drooling in Parkinson’s and really only used if drooling is a major problem (otherwise, very bad mental symptoms)
Tox: Confusion, impaired memory, hallucinations, typical anticholinergics (dry mouth,etc)
Misc: Contraindicated in demented Parkinson’s; abrupt discontinuation exacerbates symptoms
Ethopropazine
Class: Anticholinergics
Mech: N/A
Thera: Tremor and drooling in Parkinson’s and really only used if drooling is a major problem (otherwise, very bad mental symptoms)
Tox: Confusion, impaired memory, hallucinations, typical anticholinergics (dry mouth,etc)
Misc: Contraindicated in demented Parkinson’s; abrupt discontinuation exacerbates symptoms
Amantadine
Class: Anti-viral
Mech: Dopaminergic, anticholinergic, anti-NMDA
Thera: Mild early Parkinson’s (2nd line); best as an adjunct to levodopa/carbidopa for long-term treatment; movement disorders in HD; only adjunct that reduces dyskinesias
Tox: DA side effects, edema, psychosis, NMS upon withdrawal
Misc: Excreted unchanged in urine (renal dysfunction requires lower dose); contraindicated in elderly with dementia (anticholinergic effects)
Deep Brain Stimulation
Class: Surgery
Mech: Hits subthalamic nucleus
Thera: Treatment for motor fluctuations or dyskinesias refractory to other meds; reduces off time, may reduce levodopa dosage.
Tox: Fatal intracerebral hemorrhage, cognitive impairment
Misc: Patients must still be sensitive to levodopa therapy (or they aren’t a candidate)
