A 70-year-old man being treated for Parkinson disease develops the above appearance of his legs.
Which of the following agents is most likely responsible?
- A) Amantadine
- B) Levodopa/carbidopa
- C) Bromocriptine
- D) Pergolide
- E) Pramipexole
- F) Ropinirole
- G) Cabergoline
- H) Selegiline
- I) Tolcapone
0 voters
The answer is A.
This patient has livedo reticularis, a cutaneous sign characterized by a blotchy and lace-like,
reddish-blue to purple appearance.
Amantadine, a dopamine reuptake inhibitor sometimes used in Parkinson disease, can cause livedo
reticularis.1, 2
Is is believed that livedo reticularis is a physiological response provoked by depletion of
catecholamine stores in peripheral nerve terminals.3
Levodopa/carbidopa is a frequently used formulation in Parkinson disease. Dopamine does not
cross the blood-brain barrier (BBB), but L-dopa does.4 Carbidopa, an L-dopa decarboxylase
inhibitor, decreases the amount of L-dopa converted to dopamine peripherally so that more can
cross the BBB, where it is then converted to dopamine.5
Bromocriptine, pergolide, pramipexole, ropinirole, and cabergoline are all dopamine receptor
agonists that may be used in Parkinson disease.6
Selegiline is a selective monoamine oxidase B (MAO-B) inhibitor used in Parkinson disease.7
Tolcapone, a catechol-O-methyltransferase (COMT) inhibitor used in Parkinson disease, decreases
the metabolism of L-dopa so that more is available to cross the BBB