Antidepressants Flashcards
What is the goal of antidepressant treatment?
To promote long-term adaptations in serotonergic (5-HT) or noradrenergic (NE) neurotransmission, leading to improved depression symptoms.
What are the major classes of antidepressants?
SSRIs, SNRIs, TCAs, MAOIs, Atypical Antidepressants (including bupropion, mirtazapine, and trazodone).
What is serotonin syndrome, and how is it treated?
A life-threatening condition caused by excessive serotonin. Symptoms: hyperthermia, hypertension, hyperreflexia, hyperstimulation (diarrhea, mydriasis, sweating). Treatment: Cyproheptadine (5-HT2 antagonist).
What is the mechanism of action of SSRIs?
They inhibit SERT, increasing synaptic serotonin (5-HT) levels.
What are the main indications for SSRIs?
Major depression, anxiety disorders, OCD, bulimia, menopausal hot flashes, fibromyalgia.
Name a prototypical SSRI and other commonly used SSRIs.
Prototypical: Fluoxetine (Prozac). Common: Sertraline (Zoloft), Escitalopram (Lexapro).
What are the main adverse effects of SSRIs?
Nausea, anxiety (initially), sexual dysfunction, weight gain, increased bleeding, discontinuation syndrome.
Why does fluoxetine have a lower risk of discontinuation syndrome?
It has long-acting metabolites that naturally taper off the drug.
What is the mechanism of action of SNRIs?
They inhibit SERT & NET, increasing both serotonin (5-HT) and norepinephrine (NE) levels.
What are the main therapeutic indications of SNRIs?
Major depression, neuropathic pain, fibromyalgia, chronic pain.
Name a prototypical SNRI and commonly used alternatives.
Prototypical: Venlafaxine (Effexor). Common alternative: Duloxetine (Cymbalta) (used for pain management).
What are the adverse effects of SNRIs?
Same as SSRIs, but may also worsen hypertension and anxiety initially.
What is the mechanism of action of Bupropion?
It inhibits DAT (dopamine transporter) & NET, increasing dopamine (DA) and norepinephrine (NE).
What are the main therapeutic indications for Bupropion?
Major depression, ADHD, smoking cessation, obesity (FDA-approved for weight loss).
What are the major advantages and adverse effects of Bupropion?
Advantages: No sedation, no sexual dysfunction, improves focus. Adverse: Seizure risk (avoid in epilepsy, alcohol withdrawal), may worsen hypertension.
What is the mechanism of action of Mirtazapine?
Alpha-2 adrenergic antagonist (increases NE & 5-HT release), also blocks 5-HT2A receptors.
What are the major indications and adverse effects of Mirtazapine?
Indications: Depression with insomnia. Adverse: Sedation, weight gain, dizziness (vestibular effects).
What is the mechanism of action of Trazodone?
Weak SERT inhibitor, blocks 5-HT2A and alpha-1 adrenergic receptors.
What are the main indications and adverse effects of Trazodone?
Indications: Depression with insomnia. Adverse: Sedation, weight gain, orthostatic hypotension, priapism (rare).
What is the mechanism of action of TCAs?
Inhibit SERT & NET (NET > SERT), also block alpha-1, histamine, and muscarinic receptors.
Name a prototypical TCA and its indications.
Prototypical: Amitriptyline (Elavil). Indications: Refractory depression, neuropathic pain, insomnia, bedwetting (enuresis).
What are the major adverse effects of TCAs?
Anticholinergic (dry mouth, constipation, urinary retention), weight gain, drowsiness, arrhythmias, orthostatic hypotension.
Why are TCAs dangerous in overdose?
Low therapeutic index (TI = 3), overdose can cause: 3 Cās: Cardiac arrhythmias (Na+ channel block) ā fatal ventricular fibrillation, Convulsions, Coma. Emergency Treatment: Sodium bicarbonate (NaHCO3) to stabilize cardiac membranes.
What is the mechanism of action of MAOIs?
They inhibit MAO-A, preventing the breakdown of serotonin, norepinephrine, and dopamine.
Name a prototypical MAOI and its major concerns.
Prototypical: Phenelzine (Nardil). Major concerns: Hypertensive crisis (avoid tyramine-rich foods: cheese, red wine), drug interactions, CNS agitation, seizure risk.
