Psych and CNS Flashcards
What class of drugs do Fluoxetine (Prozac), Sertraline (Zoloft), Paroxetine (Paxil), and (es)citalopram (Celexa, Lexapro) fall into?
Selective Serotonin Reuptake Inhibitors (SSRIs), antidepressants
How do SSRIs work?
Increases the amount of serotonin in the synapse
What are seven side effects of SSRIs?
Insomnia, agitation, headache, nausea, diarrhea, sexual dysfunction, and platelet dysfunction
Which drugs cause Hepatic cytochrome P-450 inhibition?
Fluoxetine, metoprolol (elimination half-life 3-4hrs), increased levels of TCAs, and some neuroleptics
What symptoms does a patient have with Serotonin Syndrome?
Anxiety, restlessness, chills, ataxia, insomnia
What drugs increase the potential for Serotonin Syndrome when given with SSRIs?
MAOIs, Carbamazepine, Linezolid (antibiotic)
Yes or No, Is an overdose of SSRIs typically lethal?
No
Name two other commonly used antidepressants that inhibit the reuptake of neurotransmitters other than Serotonin.
Venlafaxine (Effexor) and Buproprion (Wellbutrin, Zyban)
What are some examples of Tricyclic Antidepressants (TCAs)?
AmiTRIPTYLINE (Elavil), NorTRIPTLYINE, imiPRAMINE, clomiPRIMINE
What is the mechanism of action of TCAs?
Block the reuptake of norepinephrine (sometimes serotonin)
What are the advantages and disadvantages of TCAs?
Highly effective for depression, poor side-effect profiles
What are the side-effects of TCAs?
Anticholinergic side effects: dry mouth, tachycardia, urinary retention, GI slowing
What are some cardiogenic side effects with TCAs?
Orthostatic hypotension, PR prolongation, cardiac depression, (myocardial depression and ventricular dysrhythmias at higher doses)
What is it about TCAs that make them lethal if overdosed?
Narrow therapeutic index
What are TCAs commonly used for at lower doses?
Chronic pain syndromes
If a patient is on TCAs, what classes of drugs should be used with caution due to their potential for drug interaction or exaggerated responses.
Sympathomimetics (especially indirect-acting), Anticholinergics (Atropine increases likelyhood of postop delirium)
Opioids and barbiturates (potentiated)
What are four examples of Monoamine Oxidase Inhibitors (MAOIs)?
Phenelzine, tranylcypromine, isocarboxazid, selegiline
What is the mechanism of action for MAOIs?
Inhibits the enzyme (MAO) that metabolizes monoamines such as dopamine, serotonin, epi, norepi
True or False: MAOIs are reversible and non-selective.
False. Most MAOIs are irreversible and non-selective
What are six side effects of MAOIs?
Orthostatic hypotension, anticholinergic side effects, sedation, sexual dysfunction, weight gain, and requires a tyramine-free diet.
If the hepatic deamination of tyramine is inhibited and your patient eats food with tyramine in it, then what kind of response do we see?
an indirect sympathomimetic response (like pheo)
What are some examples of foods that have tyramine in them?
Avocados, cheese, liver, fava beans, chianti wine
Yes or No: Can an overdose of MAOIs be lethal? And what treatment has been suggested to counter the hypermetabolism, hyperthermia state from an overdose?
yes, Dantrolene
True or false: Data has been shown to support stopping MAOIs 2-3 weeks prior to anesthesia.
False, No data to support stopping for 2-3 weeks prior.
If you discover in preop that your patient has been on MAOIs for depression and anxiety for quite sometime now, what types of drugs should be used with caution or avoided all together?
Sympathomimetics with caution (direct > indirect)
Epi w/local anesthetics should be avoided
Opioids (potentiated); Meperidine (depressive reactions)
What drug is the drug of choice for bipolar (manic-depressive) disorder?
Lithium
Why is it important to measure plasma concentrations of if a patient is given Lithium?
Lithium competes with Na for proximal tubule reabsorption in the kidney, Na is depleted causing an increase in lithium levels
What are three side effects of lithium?
polydipsia, polyuria, hypothyroidism
What drugs have a prolonged effect when given to a patient on Lithium?
NMB drugs (both depolarzing and non-depolarizing) are prolonged
What are eight symptoms of Lithium toxicity.
Lethargy, weakness, tremor, QRS widening, heart block, hypotension, confusion, and seizures
What exacerbates increased levels of Lithium?
dehydration, Na restriction, diuretics, NSAIDs
How is Lithium toxicity treated?
osmotic diuresis or dialysis
Which drugs should be avoided with a patient on Lithium?
Diuretics (loop, thiazide) and NSAIDs should be avoided
Neuroleptics: increase risk of extrapyramidal side effects (movement disorders) and NMS
What is the treatment for schizophrenia (psychosis)?
Antipsychotic Drugs (Neuroleptic)
What are five examples of Neuroleptic drugs?
Chloropromazine (Thorazine), clozapine (Clozaril), haloPERIDOL (Haldol), risPERIDONE (Risperdal), droPERIDOL
What is the mechanism of action in Neuroleptic drugs?
Blocks dopamine receptors
What is Tardive dyskinesia?
abnormal involuntary movements of face, neck, tongue
What type of reaction describes acute muscle rigidity/cramping in face/neck/tongue and larynx?
Acute dystonic reaction
What is the treatment for acute dystonic reaction?
Anticholinergics - diphenhydramine (Benadryl) or benztropine (Cogentin)
What symptoms do we see with parkinsonism?
rigidity, tremor, bradykinesia/akinesia (restlessness)
What symptoms do we see with Neuroleptic Malignant Syndrome (NMS)?
Hyperthermia, muscular hypertonicity, autonomic instability, mental status changes
What is the treatment for NMS?
Dantrolene, amantadine/bromocriptine
What class of drugs cause flaccid paralysis in NMS but not in MH?
Nondepolarizing NMBs
What cardiovascular side effects do we see with antipsychotic drugs?
alpha-blockade (orthostatic hypotension), prolonged QTc (leading to VTach and toursades)
What endocrine side effects do we see with antipsychotic drugs?
block inhibition of prolactin - galactorrhea, gynecomastia
decr corticotropin release - decr corticosterioids
Weight gain, hyperglycemia
What CNS side effect does droperidol cause?
dysphoric response
What drug class does antipsychotic drugs have an interaction with?
opioids (potentiated)
What drugs are best used to stop a seizure quickly?
antiepileptic drugs: barbiturates, benzodiazepines, propofol
What is the mechanism of action of phentoin (Dilantin)?
Na-channel blockade (also Ca, NMDA)
What is the therapeutic serum level for Dilantin?
10-20 mcg/mL
Which antiepileptic drug is 90% protein-bound and leads to a zero-order kinetics in the liver at high plasma levels?
Phenytoin (Dilantin)
What can a fast infusion of Dilantin cause?
Hypotension
What drug is a prodrug of pheytoin that can be infused rapidly without causing hypotension?
Fosphenytoin (Prodilantin)
What antiepileptic drug is given orally with no significant side effects, no hepatic metabolism, and minimal protein binding?
Levetiracetam (Kappra)
Which antiepileptic drug is most commonly used in chronic neuropathic pain and diabetic neuropathy?
Gabapentin (Neurontin)
What is the precursor to Dopamine and crosses the blood-brain barrier?
levodopa (Sinemet)
What is the enzyme that converts levadopa to dopamine?
Dopa Decarboxylase
What is usually given with levadopa to prevent decarboxylation before crossing the BBB?
Carbidopa
What is a side effect of levadopa?
orthostatic hypotension
What symptoms can develop if levodopa is stopped abruptly?
Parkinsonian symptoms, NMS
What should always be asked if your patient is taking levodopa?
“When was your last dose and what happens if you miss a dose?”
What two drugs can cause Parkinsonism due to dopamine antagonism?
haloPERIDOL and droPERIDOL
Which drugs should be avoided if your patient is taking haloperidol or droperidol?
metoclopramide (Reglan) and promethazine (phenergan)
