Pharmacology Psychiatric Flashcards
What are some typical antipsychotics? Mechanism of action?
High potency: Haloperidol, trifluoroperazine, fluphenazine Low potency: thioridazine, chlorpromazine (haloperidol + “-azines”). Block dopamine D2 receptors (increase cAMP)
Uses of typical antipsychotics?
Schizophrenia, psychosis, acute mania, Tourette’s
Toxicity of typical antipsychotics? Generally speaking.
Highly lipid soluble, takes long time to clear, greater risk of EPS than atypicals, NMS, dopamine receptor antagonism–>hyperprolactinemia–>galactorrhea
Treatment of extrapyramidal side effects?
benztropine or diphenhydramine
treatment of NMS?
dantrolene (muscle relaxant), D2 agonists (bromocriptine)
Chlorpromazine
low potency typical antipsychotic, corneal deposits
Thioridazine
low potency typical antipsychotic, retinal deposits
Haloperidol
high potency typical antipsychotic, NMS, tardive dyskinesia
What are some atypical antipsychotics? Mechanism of action? Uses?
Olanzapine, clozapine, quetiapine, risperidone, aripiprazole, ziprasidone. Varied effects on 5-HT2, D, alpha, H1 receptors. Schizophrenia, bipolar disorder, OCD, anxiety disorders.
Treatment of tourette’s syndrome?
antipsychotic (eg haloperidol or risperidone)
Toxicity profile of atypical antipsychotics
Less EPS, NMS risk than typical antipsychotics (less anticholinergic)
Olanzapine
atypical antipsychotic, significant weight gain
Clozapine
atypical antipsychotic, significant weight gain, agranulocytosis (requires weekly RBC monitoring), seizure
Risperidone
atypical antipsychotic, anti-dopaminergic effects –> increase prolactin –> lactation and manboobs –> decreased GnRH, LH, FSH –>irregular menstruation and fertility problems
Ziprasidone
atypical antipsychotic, prolong QT interval
What is mechanism of action of Lithium? Uses?
Unknown MoA (possible inhibition of phosphoinositol cascade). Mood stabilizer for bipolar disorder. Acute mania. SIADH.
Lithium toxicity?
LMNOP: Lithium, movement (tremor), Nephrogenic diabetes insipidus, hypOthyroidism, Pregnancy problems. Exclusively renal excreted and re-absorbed at PCT with Na–>requires close monitoring of serum levels
Lithium toxicity to fetus?
Ebstein anomaly (apically displaced tricuspid valve), malformation of great vessels
Buspirone. MoA? Uses? Toxicity?
Stimulates 5-HT1A receptor. Used in generalized anxiety disorder. Does NOT cause addiction/dependence but takes 1-2 weeks to become effective. Does not interact with alcohol (vs barbiturates/benzos)
What are some SSRIs? Mechanism?
Fluoxetine, paroxetine, sertraline, citalopram. 5-HT specific reuptake inhibitors (inhibit serotonin specific re-uptake pump).
Uses of SSRIs?
Depression, GAD, panic disorder, OCD, bulimia, social phobias, PTSD–First line for most things except bipolar disorder, psychosis (schizo) and tourette
Toxicity of SSRIs?
Generally fewer than TCAs, GI distress, sexual dysfunction, serotonin syndrome
What is serotonin syndrome? Causes? Tx?
Hyperthemia, confusion, myoclonus, cardiovascular collapse, flushing, diarrhea, seizures. Tx with cyproheptadine (5-HT2 receptor antagonist). Caused by any drug that increased 5HT (MAO inhibitors, SNRIs, SSRIs, TCAs)
What are some SNRIs? Mechanism?
Venlafaxine, duloxetine. Inhibit 5-HT and norepinephrine uptake.
What is an unusual use for duloxetine?
Diabetic peripheral neuropathy
SNRI toxicities?
Increased BP, stimulant effects, sedation/nausea, serotonin syndrome
What are some TCAs? Mechanism
Amitriptyline, nortriptyline, imipramine, desipramine (-iptyline and -ipramines). Block reuptake of norepinephrine and 5-HT.
TCA uses?
Major depression, OCD (clomipramine), fibromyalgia
TCA toxicities? Tx?
Sedation, alpha1-blocking effects (postural hypotension), anti-cholinergic tox (amitriptyline). Three Cs: coma, convulsions, cardiotoxic (arrythmias, prolonged QT). Tx with sodium bicarbonate for cardiac toxicity. Serotonin syndrome.
What are some MAO inhibitors? MoA?
Tranylcypromine, Phenelzine, Isocarboxazid, Selegiline. Inhibits MAO resulting in increase of amine neurotransmitters (norepi, 5-HT, dopamine)
Use of MAO inhibitors?
Never use, only as last resort given potential side effects. Atypical depression, anxiety, hypochondriasis.
MAO inhibitor toxicities?
HTN crisis from tyramine effect (wine, cheeses). CNS overstimulation.
What are some contraindications to prescribing MAO inhibitors?
Serotonin syndrome risk: SSRIs, TCAs, St John’s wort (CYP450 inducer), meperidine (opioid with 5HT-ergic effects), dextromethorphan (cough supressant, SNRI effects)
Bupropion
atypical antidepressant; smoking cessation; increases norepi and dopamine via unknown mechanism; Tox: stimulant effects/headache/seizure in bulimic patients/no sexual SEs
Mirtazapine
atypical antidepressant; alpha2-antagonist/potent 5HT2 and 5HT3 receptor antagonist (increases release of norepi and 5HT); Tox: sedation, increased appetite/weight gain
Trazadone
atypical antidepressant; insomnia; blocks 5HT2 and alpha1-adrenergic receptors; Tox: priapism, postural hypotension
