Antidepressants
SSRIs, SNRIs, bupropion, TCAs and MAOIs
| Class | Examples | Key points |
|---|---|---|
| SSRIs | sertraline, escitalopram, citalopram, fluoxetine, paroxetine | First-line for depression and anxiety. Nausea, sexual dysfunction, insomnia or sleepiness, low sodium (older adults), bleeding risk with NSAIDs/anticoagulants. Citalopram: QT (dose limits). Fluoxetine's long half-life means less withdrawal. |
| SNRIs | venlafaxine, duloxetine, desvenlafaxine | Depression, anxiety, nerve pain, fibromyalgia (duloxetine). Can raise BP; sweating; nausea. Bad withdrawal if stopped suddenly (venlafaxine). |
| NDRI | bupropion | Depression, smoking cessation. No sexual side effects or weight gain. Lowers seizure threshold: contraindicated in seizure disorders and in bulimia or anorexia (higher seizure risk). |
| Others | mirtazapine; trazodone | Mirtazapine: sedation, weight gain, take at bedtime. Trazodone: sedation (used for sleep), orthostasis, priapism (emergency). |
| Tricyclics (TCAs) | amitriptyline, nortriptyline, imipramine, clomipramine | Uses: depression, nerve pain, migraine prevention, bedwetting (imipramine), OCD (clomipramine). Anticholinergic effects, orthostasis, sedation. Deadly in overdose (wide QRS, dysrhythmias, seizures): give small supplies. Antidote: sodium bicarbonate. |
| MAOIs | phenelzine, tranylcypromine, isocarboxazid; selegiline patch | Used for treatment-resistant (and atypical) depression. Tyramine → hypertensive crisis. Many drug interactions. |
Teach for all antidepressants
- Full effect takes 4–6 weeks (some improvement may come in 1–2 weeks).
- Don't stop suddenly (discontinuation symptoms): taper.
- Boxed warning: increased suicidal thoughts in people under 25, especially early on or after dose changes. As energy returns before mood lifts, a person may act on a plan: monitor closely.
- Avoid alcohol; no St. John's wort.
MAOI diet and drug rules
Avoid tyramine: aged cheese, cured, smoked or fermented meats (salami, pepperoni), tap or draft beer, soy sauce, sauerkraut, kimchi, fava beans, overripe or spoiled food, yeast extracts.
Hypertensive crisis: severe occipital headache, stiff neck, chest pain, palpitations, sweating.
Never combine with SSRIs, SNRIs, TCAs, meperidine, tramadol, dextromethorphan, linezolid, St. John's wort. Wait 14 days after stopping an MAOI (and 5 weeks after fluoxetine before starting one).
Serotonin syndrome
Cause: too much serotonin, usually from combinations (SSRIs, SNRIs, MAOIs, tramadol, linezolid, triptans, dextromethorphan, St. John's wort). Starts within hours.
Signs: agitation, confusion, sweating, high fever, fast heart rate, clonus and hyperreflexia, tremor, diarrhea. Action: stop the drugs, cool, benzodiazepines, cyproheptadine.
Memory hook: TCA anticholinergic effects
"Can't see (blurred vision), can't pee (urinary retention), can't spit (dry mouth), can't poop (constipation)." Avoid in narrow-angle glaucoma, urinary retention, and older adults where possible.