MAOIs

Question 1

how MAOIs work

Answer 1

block monoamine oxidase (MAO), prevents breakdown of monoamines. Irreversible (irreversible mouse traps)

Question 2

isoforms of MAO

Answer 2

MOA-A (albino mouse) preferentially oxidatively de-aminates serotonin, NE, and DA (eating the smiley face, the north compass, and the DA rope)
MAO-B (black mouse) only for DA (eating DA rope)

Question 3

MAOIs

Answer 3

tranylcypromone (try a sip wine)
phenelzine (funnel on wine bottle)
isocarboxazid (boxed wine)
selegiline - a selective MAO-B inhibitor (sledgehammer by black mouse)

Question 4

MAOI uses

Answer 4

atypical depression - hyperphagia, hypersomnia, leaden paralysis (not your typical winery sign by sad and happy mask) but not first line because of their side effects
treatment resistant depression (guy struggling with resistant bottle of wine)

Question 5

selegiline

Answer 5

selective MAO-B inhibitor
especially useful in the CNS (cerebral meat hanging by mouse)
managing parkinsons with fluctuating responses to levadopa (cogwheel clock)

Question 6

MAOI side effects

Answer 6

most common: orthostatic hypotension, weight gain, highest sexual side effects
should be avoided with tyramine containing foods - aged meats, cheese, and wine (tyramine is metabolized in the GI tract by MAO-A (albino mouse eating the meat) with MAOI all the tyramine flows into the general circulation and acts a a sympathomimetic agent causing pressor response (vasoconstriction, HTN, tachycardia, blurry vision, diaphoresis) seen with the lady with red sweaty face, and pressure out ears) and malignant HTN leading to stroke/MI so low tyramine diet needed
serotonin syndrome (autonomic instability, agitation, hyperthermia, HTN, hyperreflexia, clonus)

Question 7

how long before giving MAOI do you need to discontinue serotonin antidepressants (SSRI, SNRI, TOAs)

Answer 7

2 weeks

Question 8

treatment of tyramine toxicity

Answer 8

phentolamine (alpha 1 and 2 blocker) - phantom of the alpha

treats the hypertensive symptoms