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Flashcards in Lec 74 Antidepressants Deck (60)
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1

What are the classes of antidepressants?

- MAO inhibitors
- tricyclic antidepressants
- selective serotonin reuptake inhibitors
- antidepressants with multiple receptor targets

2

What is therapeutic use of MAO inhibitors?

atypical depression
anxiety
hypochondriasis

treatment resistant depression/panic disorder/social anxiety disorder

3

What is mech of action of MAO inhibitors?

- irreversibly inhibit degradation of MAOs in presynaptic terminals
- causes increase 5HT, NE, DA in presynaptic terminals and synaptic cleft

4

What are substrates of MAO-A vs MAO-B?

MAO-A: 5HT, NE, DA
MAO-B: phenylethylamine, DA [NOT 5HT, NE]

5

What is first aid mnemonic for MAO inhibitors?

MAO takes pride in shanghai

- MAO
- Tranylcypromine
- Phenelzine
- Isocarboxazid
- Selegiline

6

What are the side effects of MAO inhibitors?

serotonin syndrome if combined w/ other 5HT drugs

hypertension if combined with tyramine diet or drugs that are adrenergic agonists

orthostatic hypotension, weight gain, insomnia, sexual dysfunction, rare hepatotoxicity [for phenelzine + iso]

7

What are symptoms of serotonin syndrome?

symptoms: ab pain, diarrhea, sweating, tremor, hyperthermia, tachycardia, hypertension, myoclonus, irritability, delirium, death

8

What causes serotonin syndrome?

selected drugs in combo with MAOI

- other antidepressants
- cyclobenzapine
- carbamazepine
- dextromethorphan
- opiaties: meperidine, fentanyl, methadone
- tramadol
- st johns wort
- SSRI

9

What is a hypertensive crisis? symptoms?

defined by diastolic BP > 120
symptoms: headache, palpitations, stiff/sore neck, N/V, sweating, dilated pupils, photophobia

10

What triggers hypertensive crisis? what drugs to avoid?

triggered by noradrenergic drug + MAO inhibitor

avoid
- decongestants
- stimulants [amphetamines]
- appetite suppressants
- antidepressants with NRI [TCAs, SNRIs, buproprion]

11

What is a tyramine-induced hypertensive crisis?

- ingestion of tyramine-rich foods in presence of MAO-I can trigger hypertensive crisis
- tyramine is a catecholamine releasing agent
- intestinal wall MAO-A breaks down tyramine before absorption
- if tyramine gets access to NE sympathetic neurons --> will release NE; but don't have to worry about it because MAO-A breaks down tyramine before it gets a chance

if you inhibit MAO-A --> can't handle dietary tyramine, release NE and no MAO-A to destroy it --> increased BP

12

What foods should you avoid on MAO-I?

avoid: soy, beer, red wine, aged cheese, dried sausage, fava beans, liver, smoked fish, sauerkraut

continue diet for 2 wks after stopping MAO-I to allow re-synthesis of MAO-A

13

What is EMSAM?

selegiline transdermal path for treatment of depression
- at low levels selegiline inhibits MAO-B but at antidepressent level inhibits A and B
- goal to bypass GI tract and liver to minimize chance of hypertensive crisis if tyramine is ingested

dietary restriction at > 6mg/24 hr

14

What kind of drug is phenelzine?

MAO inhibitor

15

What kind of drug is tranylcypromine?

MAO inhibitor

16

What kind of drug is selegiline?

MAO inhibitor --> selective for MAO-B at low doses; but acts on both at anti-depressant levels

17

What is therapeutic use for tricyclic antidepressants?

- major depression
- OCD [clomipramine]
- fibromyalgia

depression + treatment resistant depression
childhood enuresis [imipramine]
generalized anxiety disorder
insomnia
obsessive compulsive disorder
migraine
cataplexy syndrome [imipramine]
fibromyalgia
prurits/dermatologic

18

What is mech of action tricyclic antidepressants?

- block presynaptic reuptake of NE and 5HT
- secondary = NE only; tertiary = NE + 5HT
- causes NT accumulation in synaptic cleft

19

What are side effects of TCAs?

sedation, weight gain [H1 block]

a1 blockade --> orthostatic hypotension, dizziness

atropine [anti-ACh] side effects: urinary retention, dry mouth, tachycardia

20

What are side effects unique to despiramine?

- less sedating [H] but higher seizure incidence
- least alpha 1 blockade

21

Do tertiary or secondary amines have more anticholinergic effects?

tertiary > secondary

22

what are the Tri-C's of tricyclic antidepressants?

TriC = convulsion, coma, cardiotoxicity [arrhythmias]

23

Why should you use nortriptyline in elderly?

its a secondary amine = less anti-ACh effects
causes confusion and hallucination in elderly

24

How do you treat tricyclic antidepressant cardio toxicity?

NaHCO3

25

Which TCAs have least anticholinergic effects?

secondary amines [desipramine, nortriptyline]

26

Which TCAs have most antihistamigeric effect?

doxepin

27

Which TCAs have least alpha 1 blockade?

secondary amines [desipramine, nortriptyline]

28

What happens in TCA overdose?

lethal

29

Who should you avoid TCA in?

pts with narrow angle glaucoma, recent cardiac events, cardiac conduction delays, prolonged GTc

30

Are tertiary or secondary amines beter in elderly?

secondary