Exam 2 NURS 660 questions with complete solutions

Fluoxetine (Prozac) Major Side Effects SSRI correct answer: -Sexual dysfunction (men: delayed ejaculation, erectile dysfunction; men and women: decreased sexual desire, anorgasmia) -Gastrointestinal (decreased appetite, nausea, diarrhea, constipation, dry mouth) -Mostly CNS (insomnia but also sedation, agitation, tremors, headache, dizziness) Note: patients with diagnosed or undiagnosed bipolar or psychotic disorders may be more vulnerable to CNS-activating actions of SSRIs -Autonomic (sweating) -Bruising and rare bleeding SIADH (syndrome of inappropriate antidiuretic hormone secretion) -Fluoxetine's unique 5HT2C antagonist properties could contribute to agitation, anxiety, and undesirable activation, especially early in dosing Fluoxetine major adverse effects correct answer: Rare seizures Rare induction of mania Rare activation of suicidal ideation and behavior (suicidality) (short-term studies did not show an increase in the risk of suicidality with antidepressants compared to placebo beyond age 24) Fluoxetine major drug interactions correct answer: -Tramadol increases the risk of seizures in patients taking an antidepressant -Can increase TCA levels; use with caution with TCAs or when switching from a TCA to fluoxetine -Can cause a fatal "serotonin syndrome" when combined with MAOIs, so do not use with MAOIs or for at least 14 days after MAOIs are stopped,Do not start an MAOI for at least 5 weeks after discontinuing fluoxetine -May displace highly protein bound drugs (e.g., warfarin) -Can rarely cause weakness, hyperreflexia, and incoordination when combined with sumatriptan, or possibly with other triptans, requiring careful monitoring of patient -Possible increased risk of bleeding, especially when combined with anticoagulants (e.g.,warfarin, NSAIDs) NSAIDs may impair effectiveness of SSRIs -Via CYP450 2D6 inhibition, could theoretically interfere with the analgesic actions of codeine, and increase the plasma levels of some beta blockers and of atomoxetine -Via CYP450 2D6 inhibition, fluoxetine could theoretically increase concentrations of thioridazine and cause dangerous cardiac arrhythmias -May reduce the clearance of diazepam or trazodone, thus increasing their levels -Via CYP450 3A4 inhibition, may increase the levels of alprazolam, buspirone, and triazolam -Via CYP450 3A4 inhibition, fluoxetine could theoretically increase concentrations of certain cholesterol lowering HMG CoA reductase inhibitors, especially simvastatin, atorvastatin, and lovastatin, but not pravastatin or fluvastatin, which would increase the risk of rhabdomyolysis; thus, coadministration of fluoxetine with certain ----HMG CoA reductase inhibitors should proceed with caution Via CYP450 3A4 inhibition, fluoxetine could theoretically increase the concentrations of pimozide, and cause QTc prolongation and dangerous cardiac arrhythmias Fluoxetine lab tests *Don't have to taper! correct answer: none in healthy individuals Fluoxetine neurotransmitters correct answer: -serotonin -norepinephrine (bc of antagonistic properties5HT2C receptors) -dopamine (bc of antagonistic properties at 5HT2C receptors) Fluoxetine pregnancy risk correct answer: not recommended, especially in first trimester -may need to continue @ 3rd trimester if depressive disorder increased postpartum depression -Neonates exposed to SSRIs or SNRIs late in the third trimester have developed complications requiring prolonged hospitalization, respiratory support, and tube feeding; reported symptoms are consistent with either a direct toxic effect of SSRIs and SNRIs or, possibly, a drug discontinuation syndrome, and include respiratory distress, cyanosis, apnea, seizures, temperature instability, feeding difficulty, vomiting, hypoglycemia, hypotonia, hypertonia, hyperreflexia, tremor, jitteriness, irritability, and constant crying Fluoxetine mechanism of action correct answer: -Boosts neurotransmitter serotonin -Blocks serotonin reuptake pump (serotonin transporter) -Desensitizes serotonin receptors, especially serotonin 1A receptors -Presumably increases serotonergic neurotransmission -Fluoxetine also has antagonist properties at 5HT2C receptors, which could increase norepinephrine and dopamine neurotransmission Escitalopram (Lexapro) Major Side Effects SSRI *May be best tolerated anti-depressants *may be assoc w/ less sexual dysfunction *least interaction w/ CYP 2D6 and 3A4 correct answer: -Sexual dysfunction -GI (dry mouth, constipation, nausea, diarrhea, decreased appetite) -Mostly central nervous system (insomnia but also sedation, agitation, tremors, headache, dizziness) Note: patients with diagnosed or undiagnosed bipolar or psychotic disorders may be more vulnerable to CNS-activating actions of SSRIs -Autonomic (sweating) -Bruising and rare bleeding -Rare hyponatremia (mostly in elderly patients and generally reversible on discontinuation of escitalopram -SIADH (syndrome of inappropriate antidiuretic hormone secretion)