University:
University of North Carolina at Chapel Hill
Course:
NURS 312 | Pharmacology
Academic year:

2020
Views:

477

Pages:

1
Author:

Carissa Thomas

3.2 – “I want to ride my tricycle tricycle”: ”: Tricyclic anti antidepressants depressants • Depression is thought to be related to a deficiency of CNS serotonin, NE, dopamine. There is a clear role for enhancing availability of synaptic monoamines to address disease. TCAs are 2nd or 3rd line in treatment of depression because of adverse effects, and are generally reserved for patients with treatment resistant depression (student struggling with resistant door to drama room, marked by comedy/tragedy masks) Tricyclic antidepressants (TCAs) (tricycle) • Include imipramine & derivatives desipramine, clomipramine (imprint of ball on girl’s face); amitriptyline, nortriptyline (girl tripping over trike) • Inhibit presynaptic norepinephrine & 5HT reuptake by blocking NET & SERT (blocked uptake of compass & smiley-face balls) • Off label uses: o Pain disorders, neuropathic & otherwise; notably diabetic neuropathy (kid stuck in Diasweeties machine) & chronic pain (frayed wire) o Migraine prophylaxis, especially Amitriptyline (school bell). o Clomipramine may be used to treat OCD, although SSRIs first line (child very neatly arranging marbles). o Central blockade of H1 histamine receptors, so may be used with allergies (bee ball) • Adverse effects o Many effects are a direct result of anticholinergic activity d/t inhibition of muscarinic acetylcholine receptors (child playing Mad Hatter’s tea party). ▪ Amitriptyline has most potent anticholinergic effect ▪ Less prevalent with secondary amines (e.g. nortriptyline & desipramine) (kid hiding under Secondary School sign) o Sexual dysfunction (rejected advances) o Relatively contraindicated in elderly patients d/t severe anticholinergic & antihistamine effects (just like dodgeball) (older man holding head) ▪ Urinary retention can be a clue to anticholinergic toxicity in delirium (bladder shaped tea kettle) o Central block of H1 histamine receptors can cause ↑appetite & weight gain (bee ball; heavy kid eating) o Can block α-1 receptors (extinguished α-1 candle). Can cause peripheral vasodilation & orthostatic hypotension, especially in the elderly (fainted girl) o CV toxicity ▪ Fatal cardiac arrhythmias are the most common cause of death in OD d/t blockage of fast Na channels (broken heartshaped peanut cookies; peanut butter jar). Causes ↓cardiac conduction → QRS & QT prolongation & arrhythmias (QRS shaped crack in bake sale sign; torsades streamers). ▪ Contractility depression can cause fatal hypotension. ▪ When a patient on TCAs presents with widened QRS or ventricular arrhythmia, treat with sodium bicarb (girl throwing baking soda). Alkalinizes serum, favoring non-ionized form of the drug which decreases affinity for Na channels. Also increases extracellular Na, allowing outcompetition of TCAs. o Seizures, probably d/t antagonist effect of TCAs on GABA-A receptor (kid in convulsions) o Serotonin syndrome (stack of smiley faced balls) o Can cause coma (kid sleeping it off) o *3 C’s: Cardiac, coma, convulsions