Ex3 Psychoactive Rx Flashcards
onset for antidepressants
Up to 2 weeks
Generally - ok to hold medications?
No, unless NPO/high TF residuals
TCA medications
end in “triptyline”, “ipramine”, “epin”
amitriptyline, imipramine, desipramine, doxepin, nortriptyline
TCA indications
depression
unique: chronic pain
TCA MOA
- inhibit Serotonin/Norepi reuptake
2. Antagonistic: histamine, anti-muscarinic acetylcholine, alpha1 adrenergic, NMDA, mu opioid
Metabolism of TCAs
Liver - P450
Active metabolites, erratic bioavailability, long half life (>24h)
TCA common side effects
- Hypotension (increased in elderly)
- Anticholinergic/antihistmaine: Urinary retention
- fine tremors, Sedation, confusion, delirium
- Prolonged QTc (Check EKG prior to case)
- Gastric motility, ileus
TCA dosage effect
narrow therapeutic index: EKG changes
Risk of TCA
Reduced seizure threshold
Serotonin Syndrome (avoid w/ MAOI)
Withdrawal
TCA anesthesia considerations
Exaggerated (new) or Diminished (chronic) response to sympathomimetics
Benadryl/Scopolamine w/ TCA
additive effects - excess sedation/confusion/delirium
SSRI metabolism
Liver via CYP450
Longest acting SSRI
Fluoxetine, 1-4 days
Shortest acting SSRI
Fluvoxamine, 15h
Which SSRI would it be okay to miss a few doses (days) without issues?
Fluoxetine (d/t long half life + active metabolite)
Side effects of SSRIs
BBW: suicide under age 24
Hyponatremia (SIADH)
adverse effects of escitalopram/citalopram
QTc prolongation
SSRI withdrawal
1-7 days after d/c
Which SSRI should you be concerned with withdrawal in OR?
Fluvoxamine
SSRI risk
serotonin syndrome - MAOIs, opioids, linezolid, methylene blue
AE mirtazipine
decreased seizure threshold
SNRIs
venlafaxine, duloxetine
SNRI indications
depression, pain
AE SNRIs
withdrawal (1/2 life=5 hours), active metabolites
Decreased seizure threshold
clinical indications - trazodone/nefazodone
depression, insomnia
AEs trazodone/nefazodone
sedation, orthostatic hypotension, QT prolongation, impairment of platelet aggregation
S/S serotonin syndrom
hyperthermia, confusion, agitation, autonomic hyperactivity, myoclonus, hyperreflexia, diaphoresis, tremor, diarrhea, neuromuscular abnormalities, ocular clonus
risk of serotonin syndrome occurs with
serotonin inhibitors + antiemetic (zofran/reglan), fentanyl, linezolid, meperidine, tramadol, valproic acid
Tx serotonin syndrome
- stop offending agent
2. serotonin antagonists (cyproheptadine)
prevention of serotonin syndrome
14 day washout
inadequate analgesia may occur in serotonin inhibitors with
codeine
increased risk of _____ in serotonin inhibitors
bleeding
used for smoking cessation
bupropion
MOA norepi/dopa reuptake
bupropion
AE Bupriopion
abrupt w/d=seiz risk
increased HR/BP
MAOIs
phenelzine, selegiline, tranylcypromine
MOA MAOIs
inhibits MAO (monoamine oxidase enzyme) which breaks down Serotonin/norepi/dopa
MAOI Rx Intxns
Opiates, meperidine, any Rx that effects serotonin = serotonin syndrome
AE MAOIs
myoclonic movements
Decreased use of MAOIs
intxn w/ tyramine (cheese/wine)
Effect of tyramine + MAOIs
HTN, tachycardia
Contraindicated with MAOIs
meperidine
DOC - patient with serotonin syndrome has pain
morphine
Cautious during use of _____ with MAOIs
vasopressors - exaggerated response
Etomidate is ____ to use with MAOIs
safe
Goal serum concentration - Lithium
0.6-1 mEq/L
Chronic Side Effects - Lithium
nephrogenic diabetes insipidus, polyuria/polydipsia, hypothyroidism, myxedema coma
Lithium overdose
CNS effects - seizures, coma, tremor, ventricular arrhythmias, t wave inversion, confusion, N/V/D
Increases risk of Lithium Toxicity
Renal insufficiency, hyponatremia
Drug interactions to monitor for w/ Lithium
Thiazide Diuretics, Loop diuretics, NSAIDs, neuroleptic Rx, neuromuscular blockade
AE Lithium + neuromuscular blockade
prolonged duration of NMBA
AE Lithium + diuretic/NSAIDs
Altered Sodium excretion –> renal effect –> increased lithium plasma concentration
AE Lithium + neuroleptic drugs
i.e. reglan
increased EPS, increased risk neuroleptic malignant syndrome
Typical antipsychotics
chlorpromazine, droperidol, fluphenazine, haloperidol, prochlorperazine
Atypical antipsychotics
aripiprazole, olanzipine, quetapine, risperidone, ziprasidone, loxapine, clozapine
MOA antipsychotics
“dirty” - typical vs. atypical
MOA typical antipsychotics
High D2 antagonism, Low 5HT-2A antagonism
MOA atypical antipsychotics
Moderate-high D2 antagonism, High 5-HT2A antagonism
Clozapine AEs
agranulocytosis (1st 3months), myocarditis/cardiomyopathy, seizures
antipsychotic side effects
QTc prolongation**, postural hypotension, sedation, EPS, akathisia, tardive dyskinesia, urinary retention, blurred vision, dystonia
Tardive dyskinesia presentation
repetitive/jerking movements in face, neck, tongue, lips (may affect breathing/swallowing)
Dystonia presentation
sustained muscle contractions (twisting, repetitive movements, abnormal postures), tremor/loss of facial expressions, skeletal muscle rigidity
Tardive dyskinesia tx
no treatment - anticholinergics worsen symptoms
Dystonia tx
IV benadryl 25-50 mg
benztropine 2mg
dose reduction/avoidance
akathesia
restlessness, urge to move
akathesia tx
propranolol (1st line), benzos, anticholinergic (benztropine), amantadine, clonidine
Parkinsonism
muscle rigidity, tremor, bradykinesia, postural abnormalities, salivation
parkinsonism tx
dose reduction/drug avoidance + anticholinergic (benztropine)
risk of antipsychotics
neuroleptic malignant syndrome
how to differentiate between NMS/serotonin syndrome
history
s/s neuroleptic malignant syndrome
Fever**
renal failure, rhabdo, rigidity, altered LOC, autonomic dysfunction
Tx NMS
dantrolene 0.5-2.5mg/kg q6h
NMS may mimic
malignant hyperthermia
benzos act on
Alpha/Gamma subunit of GABA-A receptor
benzodiazepine metabolism
significant hepatic metabolism
some rx = active metabolites
Benzodiazepines with active metabolites
midazolam, diazepam, chlordiazepoxide (Librium)
Benzodiazepines with inactive metabolites
oxazepam, lorazepam, temazepam
DOC benzo (renal insufficiency, repeated doses)
Lorazepam
Anesthesiology considerations in patients taking Benzos
- additive effects w/ other sedatives
- abrupt stopping of chronic therapy = w/d