MAOIs

Question 1

How were MAOI’s discovered?

Answer 1

Accidentally: they were initially TB medication and discovered when TB pts were feeling better

Question 2

What is MAOI mechanism of action?

Answer 2

They are IRREVERSIBLE inhibitors of MAO-A and MAO-B.
They inhibit the breakdown of NT’s (SER; NE; DA) causing toxicity

Question 3

Examples of MAOI’s

Answer 3

Phenelzine (Nardil); Tranylcypromine (Parnate)

Question 4

What are exogenous MAO’s

Answer 4

Exogenous MAO’s (tyramine) are what cause significant interactions. High tyrosine foods include:
Aged cheese; sour cream; yogurt; cottage cheese; wine (chianti, sherry); beer; aged/processed meats; MSG; fava beans; licorice; soy sauce; coffee; sauerkraut

Question 5

What are side effects of MAOI/toxicity (what’s the most concerning)?

Answer 5

HYPERTENSIVE CRISIS
postural hypotension (elderly); wt gain, sex SE, HA, n/v, stiff neck, diaphoresis
Especially bad with foods high in tyrosine or meds with hypertensive effects (ie pseudofed)
Sx can last up to 2 weeks: this is how long it takes to regenerate MAO-A/B

Question 6

What are medications likely to interact with MAOIs?

Answer 6

Meds that have hypertensive properties:
Amphetamines
Appetite Suppressants
Asthma medications
Decongestants
Cocaine
Other anti-depressants

Question 7

Why do we keep MAOIs around?

Answer 7

They are highly effective for some anxiety d/o (ie panic, social). Though they are most powerful drug class for treatment of unipolar depression the high risk of side effects make them last resort due to more effective, safer medications (SSRI/SNIR). Considered a last resort for treatment resistant individuals