MAO is considered as “Safety Valve” MAOA&BI is irreversibly inactivate MAO, → ↑5-HT, NE, DA and leakage into synaptic cleft.

1. Prof. Sawsan Aboul-Fotouh
Department of pharmacology, faculty of Medicine, Ain-Shams University
Monoamine Oxidase Inhibitors
(MAOIs)
Stahl, 2013

2. Mechanism of actions MAOIs
MAO is considered as
“Safety Valve”
MAOA&BI is irreversibly inactivate
MAO, → ↑5-HT, NE, DA and
leakage into synaptic cleft.

3. Monoamine Oxidase Inhibitors
(MAOIs)
Non-Selective
MAOA&B I: Tranylcypromine & Phenelzine
Selective
MAOAI: Moclobemide
MAOBI: Selegiline/Patch
NE, 5-HT in high conc.

4. Therapeutic Uses of MAOIs
MAOIs are a last-line in Resistant Depression & Anxiety
1. MDD & Atypical depression
2. Anxiety disorders, Panic disorders, Social
phobias
3. Eating disorders

5. MAO Inhibitors
Dangerous Food & Drug
Interactions
Hypertensive
Crisis

6. B
B

7. Tyramine→ ↑NE release.
Tyramine in foods, as cheese.
a high-tyramine meal (40 mg) →↑
release of NE (1). However, MAO-A
destroys excess NE released and NO
vasoconstriction or elevation in blood
Pressure (SAFE)
Irreversible MAO-A inhibitor →MAO-A
stopping its destruction of NE (2) →
accumulation of NE.
Taking tyramine (10mg), the
combination → very large
accumulation of NE (3) → excessive
stimulation of alpha1-R → VC
→↑ blood pressure.
Stahl 2013

9. Tramadol
OTC

10. Current Psychiatry. 2018
“ ↑ Serotoninergic function….”
“MAOA I action….”
“ SRI action….”
“ ↑ 5-HT….”
“MAOA I action….”

11. • Short-acting, Reversible Inhibitor of
MAO-A (RIMA).
• Has the Advantage of a reduced risk
of cheese reaction due to:
❑ Selective MAO-A inhibitor  allows
MAO-B to metabolize tyramine.
❑ Short-reversible MAO-A inhibitor 
easily displaced by tyramine allowing
tyramine to be metabolized by MAO- A.
Moclobemide
The accumulated NE released by tyramine
(1) can displace the RIMA (2),→ normal
destruction of the extra NE (3).
Stahl 2013

12. Selegiline
(FDA approval 2006)

13. Selegiline TD Patch
(FDA approval 2006)

14. Precautions with MAOIs
1. Avoid serious drug interactions and list of the foods on
patients on nonselective MAOIs.
2. Avoid in the elderly: postural hypotension – some atropine-like
actions (other side effects: Wt gain, drowsiness, Sexual Dysfunction..).
3. Avoid TCAs or SSRIs except after 2 weeks from stopping MAOIs
“Washout period”
Moclobemide “1 Week”