ANTIDEPRESSANTS

Question 1

MAOIs

Answer 1

Hydralazines: Isocarboxazid, Phenelzine*

• non-selective MAO-A and MAO-B inhibitors
• irreversible binding
• severe drug interaction with OTC cold formulations

Non-Hydralazines: Tranylcypromine, Selegiline*
*selective MAO-B inhibitor approved for treatment of Parkinson’s

Uses: rarely used in practice today d/t toxicity and potentially lethal F/D interactions

AE: insomnia, drowsiness, orthostatic hypotension
Drug interactions: MAOI + SSRI, SNRI, or TCA can lead to ‘Serotonin Syndrome’ (hyperthermia, muscle rigidity, myoclonus, mental status change) d/t overstimulation of 5HT1A and 5HT2 receptors
Food interactions: MAOI + tyramine containing food = release of large amounts of catecholamines = HTN, tachycardia, arrhythmia, seizures

Question 2

TCAs

Answer 2

Amitriptyline, Clomipramine*, Desipramine, Nortriptyline

*associated w/ sexual dysfunction

MOA: competitive binding to SERT and NET

• good alternatives to pts unresponsive to SSRIs

-AE: blockade of muscarinic receptors, ⬆️ catecholamine activity = cardiac overstimulation, blockade of cardiac fast Na+ channels = arrhythmias, alpha-1 block = orthostatic HypoTN, reflex tachy, H1 block = weight gain and sedation
Discontinuation Syndrome

Question 3

SSRIs

Answer 3

Citalopram, Escitalopram, Fluoxetine, Fluvoxamine, Paroxetine, Sertraline
*low potential for drug interactions

• 300 to 3000 fold greater selectivity for SERT
• little blocking effect @ muscarinic, alpha and H1 receptors (better side effect profile than TCAs)

Uses: depression, other psychiatric disorders, first line treatment of premature ejaculation

Question 4

SNRI

Answer 4

Venlafaxine, Duloxetine*
*should not be administered in pts w/ hepatic insufficiency

Uses: depression in pts unresponsive to SSRIs

-free from alpha1 and H1 blocking properties

Discontinuation Syndrome- d/t abrupt stop of venlafaxine d/t its short half life

Question 5

NDRI

Answer 5

Bupropion (+ metabolite hydroxybupropion) inhibit NE and dopamine reuptake

• assists in ⬇️ craving and attenuating the w/drawal sxs for nicotine and tobacco users
• not associated w/ sexual dysfunction which occurs w/ SSRIs, bc it lacks the serotonergic component

Contraindications: pts w/ seizure disorders (OD can cause seizures)

Question 6

SARIs

Answer 6

Nefazodone, Trazodone*

5HT2 antagonist/Reuptake Inhibitor

*extremely sedating - most common use as an unlabeled hypnotic

Question 7

NASSA

Answer 7

Mirtazapine

-Noradrenergic and specific serotonergic antidepressant (nassa)

• inhibits presynaptic alpha-2 receptors = enhanced release of NE and serotonin
• antagonist at 5HT2 and 5HT3 receptors

AE: weight gain, sedation (d/t H1 antagonism)