Neurological Pharmacology Flashcards
Name some causes of Parkinson’s disease
Idiopathic Parkinson’s
Drug induced
Vascular
Progressive supranuclear palsy
Mutliple systems atrophy
Corticobasal degeneration
Name the drug classes used to treat Parkinson’s
Levodopa (L-DOPA)
Dopamine receptor agonist
MAO type B inhibitors
COMT inhibitors
Anticholinergics
(Amantadine)
Describe the pharmacokinetics of levodopa
Given PO and absorbed by active transport
90% inactivated by intestinal wall while 9% converted to dopamine in periphery by DOPA decarboxylase
t1/2 is 2hrs
What is L-DOPA given in combination with and name some levodopa drugs
L-DOPA is given with peripheral DOPA decarboxylase inhibitor to prevent peripheral conversion of L-DOPA to dopamine
Co-careldopa - sinemet
Co-beneldopa - madopar
What are the advantages and disadvantages of using L-DOPA
Advantages - highly efficacious and low number of side effects
Disadvantages - needs enzyme conversion, have loss of efficacy over time, involuntary movements, motor complications may occur (dyskinesias, dystonia, freezing)
Name some side effects of L-DOPA
Nausea
Anorexia
Hypotension
Psychosis - Schizophrenia-like, hallucinations, delusions, paranoia
Tachycardia
Name some of the drug that interact with L-DOPA
Anti-emetics - can be anti-dopamine
Pyridoxine (Vit B6) - increases peripheral L-DOPA breakdown
MAOIs at high dose increase risk of hypertensive crisis
Anti-psychotics - block dopamine receptors
Name some dopamine receptor agonists
Ropinirole
Pramipexole
Rotigotine (as a patch)
Apomorphine - subcutaneous. Only for those with sever motor fluctuations
Name some advantages and disadvantages of dopamine receptor therapy
Advantages - directly acting, less dyskinesias/motor complications, possible neuroprotection
Disadvantages - less efficacious than L-DOPA, impulse control disorders, more psychiatric side effects, more expensive
Name some side effects of dopamine receptor agonsits
Sedation
Hallucinations
Confusion
Nausea
Hypotension
What do MAO B do, where are they found and name some drugs which inhibit them
Monoamine oxidase B metabolise dopamine in the dopamine containing regions of the brain
MAOI include: selegilline and rasagaline
Name a COMT inhibitor, why it is used and describe how COMT inhibitors are given (name the drug)
Entacapone (COMT inhibitor) is used as it does not cross the BBB so reduces the peripheral breakdown of L-DOPA
Given in combination with L-DOPA and peripheral DOPA decarboxylase inhibitor - Stalevo
Name some anticholinergics
Trihexyphenidyl
Orphenadrine
Procyclidine
Name some advantages and disadvantages of using anticholinergics in the treatment of Parkinson’s
Advantages - treat the tremor, do not act via dopamine system
Disadvantages - no effect on bradykinesia, has antimuscarinic side effects
Anticholinergics have an antagonist effect to dopamine
Name the types of drugs used to treat myasthenia gravis
Acetycholinesterase inhibitors
Corticosteriods - decrease inflammation
Steroid sparing drugs - decrese inflammation
IV immunoglobulins
Plasmapheresis
