Pharmacodynamics plus

Question 1

What are two major differences pharmacodynamically with Nitrous Oxide than the other inhalational agents?

Answer 1

No skeletal muscle relaxation

Increases both CMRO2 and CBF

Question 2

Describe ketamine’s effect on NMBDs

Answer 2

Prolongation of non depolarizers and increased apnea with succinylcholine

Question 3

Which drugs are contraindicated for patients with porphyria?

Answer 3

Etomidate - because increases heme production, benzos and barbs - because they decrease platelet aggregating factor

Question 4

When is the best time to give ketamine?

Answer 4

On incision, when NMDA receptors are firing

Question 5

What are the five effects of benzodiazepines?

Answer 5

Anxiolysis, sedation/hypnosis, anticonvulsant, spinal cord mediated skeletal muscle relaxation, anterograde amnesia

Question 6

Benzos typically have minimal CV and Respiratory effects, but what drugs can exaggerate those effects

Answer 6

Opioids and alcohol (and maybe prop, but definitely the first two)

Question 7

Will midazolam prevent an increase in ICP?

Answer 7

No

Question 8

Describe the CV effects of midazolam

Answer 8

You will have a decrease in BP but an increase in HR and therefore you should see no change in CO

Question 9

If you have a compliant patient taking dilantin for their epilepsy and you give a dose of thiopental, what are you concerned for?

Answer 9

Seizure, because thiopental is a CYP450 enzyme inducer which means drugs metabolized by this pathway will have an accelerated metabolism

Question 10

What is special about the CV pharmacodynamics of methohexital?

Answer 10

Tachy reflex response causes less decrease in CO d/t decreased BP being attenuated by increased HR

Question 11

What is the drug of choice for ECT and why?

Answer 11

Methohexital becuase the methyl group on the N increases hypnotic potency and lowers seizure threshold

Question 12

In mother who receive epidurals with morphine, what is their number one complaint?

Answer 12

Itchiness! This is d/t histamine release of morphine.

Question 13

What med is meperidine contraindicated with?

Answer 13

MAOIs d/t risk for serotonin syndrome

Question 14

What are some pharmacodynamic implications of alfentanil that make it stand out from the other phenylpiperidines

Answer 14

Fast on, fast off (because decreased potency)
Less decrease in BP
Less PONV
R/F acute dystonia if given to untreated Parkinson’s patients

Question 15

you see a patient with allergic rhinitis, nasal polyps, and asthma - what is something you should think about in regards to developing your ERAS protocol

Answer 15

They are at risk for allergic reaction to acetaminophen

Question 16

What are some negative side effects of acetaminophen

Answer 16

Increased MI risk
Risk for ulcer/perf
Decreased platelet function
Liver failure

Question 17

In what patients should you avoid ketorolac as part of your ERAS protocol?

Answer 17

Patients with renal compromise

Question 18

Why is Celebrex a good choice for patients with history of GI issues?

Answer 18

It is a selective Cox 2 inhibitor, so the GI risks associated with other NSAIDs do not apply to Celebrex,

However, if the patient has CV problems, this could increase CV risk so consider naproxen instead

Question 19

What are some problems with atracurium

Answer 19

Histamine release

Laudanosine metabolite - accumulation = convulsions

Question 20

Describe the cardiac effects of pancuronium

Answer 20

This drug has vagolytic effects so increased heart rate and blood pressure