Pharmacology Psychiatric

Question 1

What are some typical antipsychotics? Mechanism of action?

Answer 1

High potency: Haloperidol, trifluoroperazine, fluphenazine Low potency: thioridazine, chlorpromazine (haloperidol + “-azines”). Block dopamine D2 receptors (increase cAMP)

Question 2

Uses of typical antipsychotics?

Answer 2

Schizophrenia, psychosis, acute mania, Tourette’s

Question 3

Toxicity of typical antipsychotics? Generally speaking.

Answer 3

Highly lipid soluble, takes long time to clear, greater risk of EPS than atypicals, NMS, dopamine receptor antagonism–>hyperprolactinemia–>galactorrhea

Question 4

Treatment of extrapyramidal side effects?

Answer 4

benztropine or diphenhydramine

Question 5

treatment of NMS?

Answer 5

dantrolene (muscle relaxant), D2 agonists (bromocriptine)

Question 6

Chlorpromazine

Answer 6

low potency typical antipsychotic, corneal deposits

Question 7

Thioridazine

Answer 7

low potency typical antipsychotic, retinal deposits

Question 8

Haloperidol

Answer 8

high potency typical antipsychotic, NMS, tardive dyskinesia

Question 9

What are some atypical antipsychotics? Mechanism of action? Uses?

Answer 9

Olanzapine, clozapine, quetiapine, risperidone, aripiprazole, ziprasidone. Varied effects on 5-HT2, D, alpha, H1 receptors. Schizophrenia, bipolar disorder, OCD, anxiety disorders.

Question 10

Treatment of tourette’s syndrome?

Answer 10

antipsychotic (eg haloperidol or risperidone)

Question 11

Toxicity profile of atypical antipsychotics

Answer 11

Less EPS, NMS risk than typical antipsychotics (less anticholinergic)

Question 12

Olanzapine

Answer 12

atypical antipsychotic, significant weight gain

Question 13

Clozapine

Answer 13

atypical antipsychotic, significant weight gain, agranulocytosis (requires weekly RBC monitoring), seizure

Question 14

Risperidone

Answer 14

atypical antipsychotic, anti-dopaminergic effects –> increase prolactin –> lactation and manboobs –> decreased GnRH, LH, FSH –>irregular menstruation and fertility problems

Question 15

Ziprasidone

Answer 15

atypical antipsychotic, prolong QT interval

Question 16

What is mechanism of action of Lithium? Uses?

Answer 16

Unknown MoA (possible inhibition of phosphoinositol cascade). Mood stabilizer for bipolar disorder. Acute mania. SIADH.

Question 17

Lithium toxicity?

Answer 17

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

Question 18

Lithium toxicity to fetus?

Answer 18

Ebstein anomaly (apically displaced tricuspid valve), malformation of great vessels

Question 19

Buspirone. MoA? Uses? Toxicity?

Answer 19

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)

Question 20

What are some SSRIs? Mechanism?

Answer 20

Fluoxetine, paroxetine, sertraline, citalopram. 5-HT specific reuptake inhibitors (inhibit serotonin specific re-uptake pump).

Question 21

Uses of SSRIs?

Answer 21

Depression, GAD, panic disorder, OCD, bulimia, social phobias, PTSD–First line for most things except bipolar disorder, psychosis (schizo) and tourette

Question 22

Toxicity of SSRIs?

Answer 22

Generally fewer than TCAs, GI distress, sexual dysfunction, serotonin syndrome

Question 23

What is serotonin syndrome? Causes? Tx?

Answer 23

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)

Question 24

What are some SNRIs? Mechanism?

Answer 24

Venlafaxine, duloxetine. Inhibit 5-HT and norepinephrine uptake.

Question 25

What is an unusual use for duloxetine?

Answer 25

Diabetic peripheral neuropathy

Question 26

SNRI toxicities?

Answer 26

Increased BP, stimulant effects, sedation/nausea, serotonin syndrome

Question 27

What are some TCAs? Mechanism

Answer 27

Amitriptyline, nortriptyline, imipramine, desipramine (-iptyline and -ipramines). Block reuptake of norepinephrine and 5-HT.

Question 28

TCA uses?

Answer 28

Major depression, OCD (clomipramine), fibromyalgia

Question 29

TCA toxicities? Tx?

Answer 29

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.

Question 30

What are some MAO inhibitors? MoA?

Answer 30

Tranylcypromine, Phenelzine, Isocarboxazid, Selegiline. Inhibits MAO resulting in increase of amine neurotransmitters (norepi, 5-HT, dopamine)

Question 31

Use of MAO inhibitors?

Answer 31

Never use, only as last resort given potential side effects. Atypical depression, anxiety, hypochondriasis.

Question 32

MAO inhibitor toxicities?

Answer 32

HTN crisis from tyramine effect (wine, cheeses). CNS overstimulation.

Question 33

What are some contraindications to prescribing MAO inhibitors?

Answer 33

Serotonin syndrome risk: SSRIs, TCAs, St John’s wort (CYP450 inducer), meperidine (opioid with 5HT-ergic effects), dextromethorphan (cough supressant, SNRI effects)

Question 34

Bupropion

Answer 34

atypical antidepressant; smoking cessation; increases norepi and dopamine via unknown mechanism; Tox: stimulant effects/headache/seizure in bulimic patients/no sexual SEs

Question 35

Mirtazapine

Answer 35

atypical antidepressant; alpha2-antagonist/potent 5HT2 and 5HT3 receptor antagonist (increases release of norepi and 5HT); Tox: sedation, increased appetite/weight gain

Question 36

Trazadone

Answer 36

atypical antidepressant; insomnia; blocks 5HT2 and alpha1-adrenergic receptors; Tox: priapism, postural hypotension