Psych (Antidepressants/Antiepileptic/Etc) SG Flashcards Preview

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Flashcards in Psych (Antidepressants/Antiepileptic/Etc) SG Deck (45)
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1

MOA of SSRIs

Block nerve terminal uptake of serotonin
Produce therapeutic action through an ability to increase 5-HT concentration

2

Clinical uses of SSRIs

effective in treating major depressive disorder

3

Metabolism of SSRIs

Oxidized by liver microsomal enzymes

(can inhibit hepatic microsomal oxidases)

4

Medication interactions with SSRIs

Caution in combination with other antidepressants, benzodiazepines, neuroleptics, carbamepazine, as blood levels can increase

5

Side effects of SSRIs

GI effects – nausea and diarrhea
CNS stimulation – insomnia and anxiety
Sexual dysfunction – aorgasmia and delayed ejaculation
Weight loss

6

Anesthesia effects of SSRIs

The anticholinergic and cardiovascular side effects (seen in the TCAs) were not present in the SSRI group

7

Examples of SSRIs

Escitalopram (lexapro)

Fluoxetine (Prozac)

Paroxetine (Paxil)

Sertraline (Zoloft)

citalopram

fluvoxamine

8

MOA of Tricyclic Antidepressants (TCAs)

Inhibition of norepinephrine neuronal reuptake
Mild effect on 5-HT serotonin concentration
All are weak alpha adrenergic antagonists
Potentiate effects of directly acting sympathomimetics
TCAs and heterocyclics block effects of indirectly acting sympathomimetics

9

Clinical uses of TCAs

Effective in treating major depressive disorder
(Benefit p 2-3 wks; Ineffective in treating schizophrenia)

10

Metabolism of TCAs

Oxidized by microsomal liver enzymes

11

Anesthetic/Medication interactions of TCAs

Anesthetics: poss. ↑ incidence of cardiac dysrhythmias on induction
Sympathomimetics: exaggerated response to these meds, use small titrations
Anticholinergics: ↑ risk of central antichol syndrome, less likely with Glycopyrrolate
AntiHTNs: rebound HTN p D/C clonidine
Opioids: ↑ analgesia and ventilatory depressant effects

12

Side effects of TCAs

Antimuscarinic effects
Tachycardia, blurred vision, constipation, dry mouth
Sedation
Toxic delirium
Seizures
Weight gain
Involuntary movements
Neuroleptic malignant syndrome

13

Anesthetic-specific effects with TCAs

Most antidepressants will lower the seizure threshold
CNS toxicity presents as a delirium with affective, cognitive, motor, and psychotic symptoms
Overdose is frequently fatal with unresolvable arrhythmias

14

Examples of TCAs

Amitriptyline (Elavil)

clomipramine

desipramine

imipramine

nortriptyline

15

MOA of MAOis

Monoamine Oxidase exists on the body as type A and type B
Transmitter amines, such as norepinephrine, are preferentially metabolized by MAO-A in brain tissue
MAO-B is involved in the catabolism of dopamine
Drugs inhibit both A and B, but A is where the therapeutic effect occurs

16

Clinical uses of MAOis

Reserved for atypical depression

Depression unresponsive to TCAs or SSRIs

Depression resistant to ECT

17

Metabolism of MAOis

oxidation and acetylation by MAO

18

Medication interactions with MAOis

Cyclic antidepressants
Fluoxetine
Cold or allergy medications
Nasal decongestants
Sympathomimetic drugs
Opioids (esp. meperidine)

19

Side effects with MAOis

  • Hepatotoxicity (explored on next card)
  • Cardiovascular effects (explored on next card)
  • Tremors
  • Ejaculatory delay
  • Orthostatic hypotension
  • Hyperpyrexia with meperidine, dextromethorphan, TCAs

20

Hepatotoxicity and CV effects with MAOis

  • Hepatotoxicity
    • Occasionally seen with long term therapy
    • Particularly for those identified as slow acetylators
    • Nonhydrazine derivatives (those used clinically now) have a lower hepatotoxicity risk
  • Cardiovascular effects
    • Can occur with ingestion of certain foods
    • Low tyrosine diet needed
    • Cheese, beer, wine (no wonder they’re depressed!)

21

Anesthesia effects with MAOis

minimize SNS stimulation and drug-induced hypotension

regional is good, but avoid epi

minimize opioids

22

Exemplars of MAOis

Phenelzine (Nardil)

Tranylcypromine (Parnate)

23

Which SSRI is most associated with cardiac dysrhythmias?

Trazadone (S&H, p. 407)

24

Treatment of TCA overdose

Management of CNS and cardiovascular toxicity (seizures: diazepam, NaHCO3, phenytoin; Vent. Dysrhythmias: NaHCO3, lidocaine, phenytoin; Heart block: isoproterenol; Hypotension: Crystalloid/colloid, NaHCO3, sympathomimetics, inotropics)

Gastric lavage may be useful p cuffed tube in place (Stoelting & Hillier, p. 414)

25

WHAT TYPES OF FOODS OR THE COMPOUND IN THE FOODS ARE NOT TOLERATED BY PATIENTS TAKING MAO INHIBITORS AND WHY?
 


Cheese, beer, Chianti wine, avocados, fava beans, liver (Dr. Lector would not have done well on an MAOi); Dietary tyramine intake may interact with MAOIs resulting in systemic hypertension (Stoelting & Hillier, p. 414)

26

MOA for Lithium

Lithium alters Na+ transport in nerve and muscle cells and results in a shift towards intraneuronal metabolism of catecholamines.

The exact MOA in the treatment of mania in unknown.

27

Side effects with Lithium

Polydipsia & polyuria

Benign T-wave flattening

Hypothyroidism

Dermatological toxicities

Sedation

Possible prolongation of NMBAs’ effects

28

Let's discuss on the next few cards the toxicities seen with   Lithium.

Toxicities closely correlate with plasma levels.

Mild: 1.0-1.5 mEq/L

(Therapeutic index 1.0-1.2 mEq/L)

Moderate: 1.6-2.5 mEq/L

Severe: >2.5 mEq/L

29

So what is normally seen with mild lithium toxicity (1.0-1.5)?

Lethargy

irritability

skeletal muscle weakness

tremor

slurred speech

nausea

30

Ok then, what are you going to see with moderate lithium toxicity (1.6-2.5) mEq/L)?

Confusion

Drowsiness

Restlessness

Unsteady gait

Coarse tremor

Skeletal muscle fasciculations

Vomiting