Basal ganglia disorders

Question 1

Dopaminergics

Answer 1

Levodopa (precursor); Pramipexole, Ropinirole, Rotigotine (synthetic agonists)

MoA - Increased dopamine synthesis and dopaminergic function

Indications - Parkinson’s disease

Adverse effects - Confusion/agitation

Interactions - MAOI

Question 2

Dopa-decarboxylase inhibitor

Answer 2

Carbidopa, benserazide

MoA - Stops breakdown of levodopa in the periphery by inhibiting dopa-decarboxylase

Indications - Parkinson’s disease

Adverse effects - confusion, agitation

Question 3

Inhibitors of Monoamine oxidase B (MAOI)

Answer 3

Selegiline, rasagiline

MoA - Inhibition of dopamine breakdown

Indications - Parkinson’s disease

Question 4

Inhibitor of COMT

Answer 4

Entacapone, tolcapone

MoA - Blockade of dopamine precursor breakdown by inhibition of COMT

Indications - Parkinson’s disease

Adverse effects - nausea and vomiting

Question 5

Anticholinergics

Answer 5

Orphenadrine, procyclidine, trihexphenidyl

MoA - muscarinic cholinergic receptor antagonist

Indications - Parkinson’s disease, muscle rigidity, side-effects of anti-psychotics

Adverse effects - dry mouth, constipation

Question 6

Dopamine-depleting drugs

Answer 6

Tetrabenazine

MoA - Blocks VMAT, preventing uptake of DA into vesicles

Indications - Huntingdon’s chorea