Lecture 4 - Pre-Op Meds (Exam 1) Flashcards
How does enteric-coated omeprazole (Prilosec) turn into an active form when ingested?
What does it specifically inhibit as do other PPIs?
It is converted into an active form by protonation in parietal cells.
These cells are in the stomach and are responsible for gastric acid secretion.
Inhibits H+ and K+ ATPase pump
Slide 17
(Omeprazole is a prodrug)
What is MOA of omeprazole?
It inhibits proton pumps that are present.
Blocks H+/K+ ATPase pumps
(so, you have to continually take omeprazole to inhibit the pumps that have been developed at least for about 5 days)
Slide 17
What is the maximum inhibition of proton pumps you can achieve with Omeprazole in about 5 days of taking it?
66%
(1/3 of the pumps are still working usually, but still decreases in acid production significantly.)
slide 17
How is Omeprazole metabolized?
CYP’s enzyme
(Theoretically, it can inhibit other drug metabolism, but not clinical significant)
Slide 17
What is the IV dosage of Omeprazole (Prilosec)
40 mg in 100ml NS over 30 minutes
There is a PO option would have to be given longer than 3 hours prior to the anticipated induction time
Slide 17
When do you give PO Omeprazole to the patient who is having surgery?
Greater than 3 hours before going to OR
Should be administered longer than 3 hours before anticipated induction for chemoprophylaxis
(You need to wait for the medication to convert from prodrug to active form)
Slide 17
What are the 4 most common side effects of H1 antagonists?
Blurred vision
Urinary retention
Dry mouth
Drowsiness
Slide 7
What are the side effects of Omeprazole (Prilosec)?
Head to Toe
Neuro:
HA
Agitation
Confusion (Cross BBB)
GI:
N/V
Abdominal Pain
Small bowel bacterial overgrowth (d/t decreased production of acid)
Flatulence
Slide 18
The following drugs block which histamine receptor: Diphenhydramine, Promethazine, Cetirizine, Loratadine?
H1
Slide 7
How is Protonix (Pantoprazole) metabolized in our body?
CYP metabolism
(No significant drug interactions)
Slide 19
Compared to Omeprazole (Prilosec), Pantoprazole (Protonix) has a _______ bioavailability and _________E 1/2 time.
Greater, Longer
Slide 19
Diphenhydramine (Benadryl) is mostly used as an …
Antipruritic:
Used to pre-treat procedure related allergies & anaphylactic reactions
Slide 8
The elimination half-time for Diphenhydramine is…
7-12 hours
Slide 8
When do you give Pantoprazole (Protonix) to the patient who is having surgery?
1 hour prior to the OR
(Decreases gastric volume and increases pH, and works as fast as Ranitidine)
Slide 19
Diphenhydramine can inhibit the afferent arc of what reflex?
Oculo-emetic reflex
Slide 8
How is domperidone different than metoclopramide?
It does not cross the BBB & has no anticholinergic activity
(Slide 27)
What is the dosage of Protonix?
40mg in 100ml IVPB over 2-15 minutes.
Slide 19
Benadryl stimulates ventilation and augments the relationship between _______ and ____________ drives
Hypoxic and hypercarbic
Slide 8
________ Increases prolactin secretion by pituitary. (To a degree)
(Prolactin: causes the breasts to grow and make milk during pregnancy and after birth; also inhibits testosterone - impotence and gynecomastia)
Domperidone
(Slide 27)
What is the dosage of Diphenhydramine?
25-50 mg
Slide 8
What is the E 1/2 time for Promethazine (Phenergan)?
9-16 hours
Slide 9
Which drug is effective as a rescue anti-emetic and can also reduce peripheral pain levels (anti-inflammatory effects?
Promethazine (Phenergan)
Slide 9
What is the dose and onset of Promethazine? (Phenergan)
12.5-25 mg
5 minutes
Slide 9
Why is Domperidone no longer FDA approved in the USA?
What country might have it?
Because it causes dysrhythmias and sudden death!
You can find it in Mexico OTC. 🇲🇽
You can find it by prescription in Canada.🇨🇦
(Slide 27)
PPI treatment is the DOC for patients who have_____.
- GERD
- Gastroduodenal Ulcers
- Acute upper GI Hemorrhage (PPI infusion after EGD treatment)
- NSAID ulcerations (specifically Omeprazole :)
Slide 20
These drugs are most commonly (not necessarily most effective) used in duodenal ulcer disease and GERD
H2 receptor antagonists
Slide 10
______ is given for patients who have NSAID ulcerations and NSAIDs are discontinued.
Omeprazole (Prilosec) or any PPI :)
Slide 20
___________ was originally developed for schizophrenia and psychosis. (Was given is super high doses)
Droperidol (inapsine) - Strong D2 antagonist
(Slide 28)
Droperidol (inapsine) is a strong D2 antagonist.
T/F?
True
(Slide 28)
What are 3 cautions when using Droperidol (inapsine)?
*Can cause extrapyramidal symptoms
*Neuroleptic malignant syndrome
*Avoid other CNS depressants: barbiturates, opioids, general anesthetics (:
(Slide 28)
For N/V, ___________ is more effective than metoclopramide/Equally effective to 4mg ondansetron (much cheaper).
Droperidol (inapsine)
(Slide 28)
Studies show, H2 blockers are better for patients who have _______.
- Aspiration Pneumonitis concerns
- Pt’s with intermittent symptoms and it’s cost-effective
(H2 blockers do not prevent Aspiration Pneumonia but prevent pneumonitis due to decrease acidity of the contents aspirated.)
Slide 20
Why did Droperidol (inapsine) receive a Black Box Warning in 2001?
Because it prolonged QT intervals/torsades with higher doses!!
It also had lots of serious drug interactions with: amiodarone, diuretics, sotalol, mineralocorticoids, calcium channel blockers!!
(Slide 28)
What if a patient forgot to take their PPI before the surgery?
Continue to give whatever they were taking at home or, if not available, whatever the facility has.
Slide 20
What is a standard dose for Droperidol (inapsine)?
Doses: 0.625-1.25mg IV
(Slide 28)
Why is Ondansetron preferred over Droperidol (inapsine)?
Ondansetron works just as well on N/V as Droperidol but it is also has less side effects and it’s much cheaper.
(Slide 28)
What would you give if a patient who has a full stomach and needs emergent surgery?
H2 blocker works faster to decrease the acidity of the stomach contents if there is volume already in the stomach - Per slide 10 H2’s decrease hyper-secretion of gastric fluids from parietal cells.
Medication that increases gastric emptying should be given like Dopamine Blockers
Slide 20
Antacids are broken down into two groups:
- Particulate - Aluminum or magnesium based. Don’t change pH or volume enough. Aspiration means acid aspiration
- Non-Particulate - Sodium, carbonate, citrate, bicarbonate base - Neutralize acid. Ex. Citrate (Bicitra)
Slide 21
What are Particulate antacids?
Particulate antacids are aluminum or magnesium based.
(example: Maalox/Mylanta)
Slide 21
_________ is released from the chromaffin cells of the small intestine and __________ vagal afferents through the 5HT3 receptors causing __________. (Especially in pregnant people!)
Serotonin
Stimulates
vomiting
(Slide 30)
Vagal afferents form different terminal endings in the gut, including direct synapses with some enteroendocrine cells named neuropods. Vagal sensory neurons monitor ingested nutrients and water from the gut and provide fast regulation of food intake and fluid homeostasis
What receptors are ubiquitous meaning that can be found in the kidney, colon, liver, lung, & stomach?
Serotonin (5-HT3) RECEPTORS
(Slide 31)
What two locations have a high concentration of Serotonin (5-HT3) RECEPTORS?
BRAIN & GI TRACT
(Slide 31)
Why are Particulate antacids are not given to patients who have full stomach?
The aspiration of aluminum or magnesium-based antacids is as bad as that of acid.
Slide 21
What are Non-particulate antacids?
Non-Particulate antacids are sodium, carbonate, citrate, and bicarbonate based. They neutralize the acid contents in the stomach. Example: Sodium citrate (Bicitra)
(Much safer than particulate antacids if you were to aspirate)
Slide 21
In our bodies, what releases Histamine?
Basophils an Mast Cells
(slide 2)
What 3 things are induced by histamine?
- Bronchoconstriction - Contraction of smooth muscles in the airway & GI tract (semester 1)
- Increased gastric acid - Secretion of stomach acid (if we were to aspirate, we would fill our lungs with this acidic fluid)
- Release of Neurotransmitters in the CNS
(slide 2)
Histamine induces what 3 neurotransmitters to be released in the CNS?
NAS
Norepinephrine
Acetylcholine
Serotonin
(slide 2)
What 4 drugs discussed induce Histamine release?
Morphine
mivacurium (Mivacron)
Protamine
atracurium (Tracrium)
(slide 3)