Monoamine Oxidase Inhibitor Side Effects

Monoamine Oxidase Inhibitors (MOA) are a class of antidepressants that includes Isocarboxazide (Marplan), Phenelzine (Nardil), Tranylcypromine (Parnate), and Selegiline (Emsam). ⁠

MAO inhibitors are prone to drug interactions that inhibit its breakdown and could lead to hypertensive crisis, serotonin syndrome, or increased psychosis.⁠

⭐ Patients taking MAO inhibitors must avoid tyramine-rich foods, including aged cheese, pickled herring, yeast extract, air-dried meats, sauerkraut, soy sauce, fava beans, and some red wines and beers as it can precipitate hypertensive crisis. Foods can become high in tyramine when they have been aged, fermented, pickled, or smoked.⁠

SNRI Side Effects

Serotonin and norepinephrine reuptake inhibitors (SNRIs) are a class of antidepressants that work by blocking serotonin and norepinephrine reuptake in the synapse (as the name suggests). ⁠

🗒️ It is important to educate patients that there is an increased risk of suicidal thinking and behavior in children, adolescents, and young adults during the first few months of therapy and it may take up to 8 weeks before therapeutic effects are recognized.⁠

SSRIs Side Effects

💊 Selective serotonin reuptake inhibitors (SSRIs) work by inhibiting 5-HT reuptake by the presynaptic cleft, thus increasing serotonin levels in the synapse.⁠ It is commonly used to treat depression, a condition thought to be linked to low levels of serotonin, dopamine, and norepinephrine. ⁠

⭐ As you can see, this mnemonic is similar to the mnemonic on the side effects of SNRIs. Since they both block serotonin reuptake, they exhibit very similar side effect profiles except SNRIs can also impact blood pressure (increase or decrease) due to the norepinephrine reuptake inhibition. SSRIs do not affect blood pressure. ⁠

In addition, SSRIs can cause weight gain in adults on long-term therapy, while SNRIs cause less of this long-term weight gain and are more associated with weight loss. ⁠