neuro13 - nishi

[ArchivalUser]

Which of the following is a selective inhibitor of monoamine oxidase
type B (MAO-B) and, therefore, useful in treating parkinsonism?
a. Bromocriptine
b. Carbidopa
c. Selegiline
d. Phenelzine
e. Tranylcypromine

[ArchivalUser]

b.?..or e.....?

[ArchivalUser]

c???

[ArchivalUser]

cc

[ArchivalUser]

C,,

[ArchivalUser]

CCCCCC


Two types of MAO have
been found: (1) MAO-A, which metabolizes norepinephrine and sero-
tonin, and (2) MAO-B, which metabolizes dopamine. Selegiline is a selective
inhibitor of MAO-B. It therefore inhibits the breakdown of dopamine
and prolongs the therapeutic effectiveness of L-dopa in parkinsonism.
Bromocriptine is a dopamine receptor agonist. Carbidopa inhibits the
peripheral metabolism of L-dopa. Both are useful in the treatment of
parkinsonism. Phenelzine and tranylcypromine are nonselective MAOIs.
Combining them with L-dopa may lead to hypertensive crises, and thus
they are not used in the therapy of parkinsonism.