Pharm U3 antidepressants Flashcards
reserpine - use and side effects
hypertension or schizophrenia. side effect: depression
what is depression associated with?
decreased functional amine-dependent synaptic transmission (too little CNS NE and/or 5-HT
how does cocaine treat depression symptoms?
blocks NE reuptake (most antidepressive drugs block re-uptake of both NE and 5-HT)
placebo effect: true or false
most agree that meds are beneficial over placebo for patients with very severe depression
HDRS scores
hamilton depression rating scale (mild 8-13; moderate 14-18; severe 19-22; very severe >23)
MAOIs - mechanism and example
irreversibly inhibits monoamine oxidase (breakdown of neurotransmitter inside) - tranylcypromine and phenelzine
tricyclics - mechanism and examples
inhibitors of both NE and 5-HT reuptake to a varying degree - imipramine and amitriptyline
SSRIs - mechanism and examples
selective serotonin reuptake inhibitors = fluoxetine and citalopram
SNRIs - mechanism and examples
serotonin-NE reuptake inhibitors (little difference from SSRIs)… - duloxetine and venlafaxine
atypicals - mechanism and examples
inhibit 5-HT uptake transporter, and also several proposed other mechanisms (DA reuptake inhibition, agonist, and/or antagonist at serotonin receptor sub-types, **NE reuptake inhibition, antipsychotics) - bupropion and mirtazapine
what is used to treat bipolar disorder
lithium salts, followed by carbamazepine and valproate
MAOa vs MAOb
MAOa oxidizes mainly NE, 5-HT, tyramine
MAOb oxidizes mainly DA, phenyethylamine
tranylcypromine
phenelzine
what do they inhibit, what are they used for?
tranylcypromine: inhibits both A and B - used for depression
phenelzine: inhibits both A and B - used for depression
MAOi side effects, life-threatening side effects
SE: anticholinergic, pronounced orthostatic hypotension, sexual dysfunction, weight gain, sedation varies.
Life threatening: liver MAO also inhibited so dangerous with TYRAMINE (don’t eat fermented foods or take certain other drugs)
MAOI + SSRI
serotonin syndrome
biogenic amine hypothesis
depression = too little CNS NE and/or 5-HT (amounts and/or activity)
what are the tricyclics?
desipramine, imipramine, amitriptyline, nortriptyline
problem with tricyclics
“dirty drugs” - many side effects because they block several other neurotransmitter receptors besides NE and 5-HT
side effects of tricyclics
antimuscarinic (blurred vision, constipation, confusion), alpha antagonist (orthostatic hypotension), histamine antagonist (sedation and additive sedative effects with alcohol), sympathomimetic (tremor, insomnia), CARDIAC-ARRHYTHMIAS, CONDUCTION DEFECTS - ESPECIALLY AT OVERDOSE, seizures
how are antidepressants prescribed to people?
different ratios and drug combinations for different people - personalized medicine
what are the SSRIs and SNRIs?
fluoxetine, paroxetine, citalopram, duloxetine, venlafaxine
what are the main differences between SSRIs and tricyclics?
SSRIs have longer duration, some SSRIs inhibit P450 enzymes, SSRIs much safe in OD (no seizures or cardiac arrythmia), less side effects, but more nausea and complaints of decreased sexual function
side effects of SSRIs
drug-drug interactions with fluoxetine and paroxetine
serotonin syndrome
hyperthermia, muscle rigidity, myoclonus, rapid changes in mental status, vital signs (potentially lethal)
what causes serotonin syndrome?
SSRI and MAOI interaction - increased stores of 5-HT and inhibited reuptake - marked increases of serotonin in synapses
what are the atypical antidepressants?
mirtazapine and bupropion
what is unique about bupropion?
atypical: only agent with notable selectivity for DA uptake transporter, potential side effect of lowering seizure threshold, useful in improving nicotine abstinence in quitting smokers
ketamine
NMDA receptor antagonist produces rapid antidepressant response within hours - effective in treatment resistant depressed patients
uses of antidepressants
depression, anxiety, PTSD, chronic pain, enuresis, bulimia, pre-menstrual dystrophic disorder, alcoholism
side effects of lithium
drowsiness, weight gain, tremor, polydipsia, polyuria
early warning of Li OD
nausea with vomiting
MAO lithium
causes depletion of IP3 and DAG which are important second messengers for both alpha-adrenergic and muscarinic-cholinergic transmission
