Week 2 antiemetics & GI motility (3 of 4)

Question 1

What two anticholinergics can enter the CNS?

Answer 1

Scopolamine and Atropine.

Question 2

Because these two anticholinergics can cross into the CNS, they can cause what problem?

Answer 2

Scopolamine and Atropine can cause central anticholinergic syndrome.

Question 3

What do the symptoms of central anticholinergic syndrome look like? (4 answers)

Answer 3

Symptoms range:
Restlessness,
Hallucinations,
Somnolence,
Unconsciousness

Question 4

Which anticholinergic does not cross the BBB?

Answer 4

glycopyrrolate

Question 5

What drug is the reversal of central anticholinergic syndrome and what drug class is it?

Answer 5

Physostigmine which is a parasympathomimetic, or also called cholinergic receptor simulator agent.

Question 6

The reversal drug for too much atropine would be?

Answer 6

physostigmine

Question 7

What is the dose of physostigmine (lipid-soluble tertiary amine) to reverse central anticholinergic syndrome?

Answer 7

physostigmine 15-60 mcg/kg IV. Treatment may need to be repeated every 1-2 hours.

Question 8

What three Acetylcholinesterase inhibitors are NOT effective antidotes against central anticholinergic syndrome and why?

Answer 8

Edrophonium, neostigmine, and pyridostigmine are not effective antidotes because their quaternary ammonium structure prevents these drugs from easily entering the CNS.

Question 9

Anticholinergic over dose Produces rapid onset of symptoms characteristic of muscarinic cholinergic receptor blockade: what does that look like?

Answer 9

Mouth dry: swallowing and talking become difficult,
Vision blurred,
Photophobia,
Tachycardia is prominent,
Skin dry and flush,
Rash may appear especially on face/neck/upper chest

(most important is the dry mouth and tachycardia)

Question 10

Why does the body temp increase with use of too much anticholinergic?

Answer 10

↑ in body temp. reflects inhibition of sweating by anticholinergic drugs, d/t innervation of sweat glands is by SNS nerves that release acetylcholine as the neurotransmitter.

(can’t sweat can’t cool off)

Question 11

when is increase in body temp. with anticholinergics more likely to happen?

Answer 11

when environmental temp. is increased.

Question 12

What lab is typically unchanged with anticholinergic over dose (even though you would expect it to be messed up)

Answer 12

ABGs are usually unchanged.

Question 13

due to CNS stimulation and the impact of an increased physiologic dead space d/t bronchodilation what will also increase?

Answer 13

increased min. ventilation is possible.

Question 14

What are three fatal events associated with anticholinergic over dose?

Answer 14

Seizures,
Coma,
Medullary ventilator center paralysis

Question 15

even with therapeutic dose of an anticholinergic drug what can happen in children?

Answer 15

Atropine Fever

Question 16

What age group is particularly vulnerable to developing life-threatening symptoms after an overdose with an anticholinergic?

Answer 16

small children and infants

Question 17

Reversal of overdose of anticholinergic in children and infants?

Answer 17

Physostigmine 15-60mcg/kg IV

according to Hammon start on the low end

Question 18

Why may you need repeated doses of physostigmine?

Answer 18

it is metabolized quickly

Question 19

What is barrier pressure?

Answer 19

The difference between gastric pressure and lower esophageal sphincter pressure is “barrier pressure.”

Question 20

What two meds and in what dose decreases lower esophageal sphincter pressure and decreases barrier pressure?

Answer 20

atropine 0.6mg IV or Glycopyrrolate 0.2-0.3 IV

Question 21

Because atropine and glucopyrrolate decrease lower esophageal sphincter pressure, what is more likely to occur?

Answer 21

GERD

Question 22

how long does atropine and glcopyrrolate last (in doses that cause increased GERD)

Answer 22

atropine lasts 40min. and glycopyrrolate lasts 60min.

Question 23

Reglan (metoclopramide) is also known as what type of drug?

Answer 23

Benzamide

Question 24

Benzamides (such as reglan and domperidone) stimulates GI tract via cholinergic mechanism resulting in: (three answers)

Answer 24

Contraction of lower esophageal sphincter and gastric fundus,

Increased gastric and small intestinal motility,

Decreased muscle activity in the pylorus and duodenum when stomach contracts

Question 25

Why is domperidone not used in the U.S.?

Answer 25

Domperidone not used in U.S. d/t concern of use in lactating women increases milk production.

Question 26

What medication would you NOT use on someone who has Parkinson's and why?

Answer 26

Do not use Reglan bc it is an antidopanergic.

Question 27

Reglan may have direct effect on what areas of the brain that is good for Nausea?

Answer 27

Reglan may have a direct effect on CRTZ and/or vomiting center b/c of its antidopaminergic effect.

Question 28

Because of antidopaminergic activity, Reglan should be used with caution if at all in: (name three types of patient)

Answer 28

Parkinson's disease RLS Pts with movement disorders related to dopamine inhibition or depletion.

Question 29

what kind of body movements CAN Reglan cause?

Answer 29

dystonic extrapyramidal reactions

Question 30

In pts with no known movement disorders dystonic extrapyramidal reactions occur in less than 1% who are treated chronically or acutely with Reglan?

Answer 30

Chronically

Question 31

Reports of neurologic dysfunction related to the preoperative administration of what drug?

Answer 31

Reglan

Question 32

What can happen after a single IV dose of Reglan that could cause a surgery to be cancelled?

Answer 32

Akathisia, a feeling of unease and restlessness in the lower extremities after IV dosing which are sometimes severe enough to cancel surgery.

Question 33

What can you give prior to Reglan to ease the negative pre-op symptoms?

Answer 33

Versed

Question 34

What does Reglan require (on a molecular/physiologic level) to be effective?

Answer 34

background cholinergic activity.

Question 35

What three things does Reglan do the GI tract (mostly upper GI tract)?

Answer 35

Increased smooth muscle tension in the LES and gastric fundus Increased gastric and small intestinal motility Relaxation of the pylorus and duodenum during contraction of stomach

Question 36

What does Reglan sensitize the GI smooth muscles to?

Answer 36

the effects of acetylcholine!

Question 37

With conventional cholinergic drugs you do not have to have background cholinergic activity to be effective, but what med requires background cholinergic activity to be effective?

Answer 37

Reglan

Question 38

what drug opposes reglan-induced increases in LES tone and GI hypermotility?

Answer 38

Atropine

Question 39

Reglan acts as a WHAT-receptor antagonist?

Answer 39

dopamine-receptor antagonist

Question 40

Can reglan cross the BBB?

Answer 40

YES!

Question 41

Because Reglan can cross the BBB and because it is an antidopanergic, what does this all come together to mean?

Answer 41

can produce significant extrapyramidal side effects, and why it is not given to parkinson patients.

Question 42

Reglan induced antagonism of the dopamine-agonist effects on the chemoreceptor trigger zone (outside the blood brain barrier) contributes to what effect?

Answer 42

antiemetic effect!

Question 43

What drug can cause the release of acetylcholine from cholinergic nerve endings?

Answer 43

Reglan

Question 44

There are cholinergic nerves in the walls of the GI tract, would you say Reglan does or does not act on these post-ganglionic cholinergic nerves?

Answer 44

Reglan does, (below explanation from ppt) Atropine opposes reglan-induced increases in LES tone and GI hypermotility which indicates that reglan acts on post-ganglionic cholinergic nerves intrinsic to the wall of the GI tract.

Question 45

What ways can reglan be given?

Answer 45

ORAL and IV

Question 46

Reglan is rapidly absorbed after oral administration. Peak plasma concentrations occur at what time?

Answer 46

40-120 min

Question 47

Does Reglan go through first -pass metabolism?

Answer 47

Extensive first-pass hepatic metabolism limits bioavailability to 75%

Question 48

half-life of reglan?

Answer 48

2-4 hours

Question 49

We already know that Reglan DOES cross the BBB but does it cross the placenta?

Answer 49

Yes

Question 50

will you decrease the dose of reglan if someone has renal impairment?

Answer 50

Renal impairment prolongs elimination half life and necessitates a decrease in Reglan dose.

Question 51

What are Reglans clinical uses?

Answer 51

pre-op decrease gastric fluid volume. antiemetic effect Treatment of gastroparesis Symptomatic treatment of GERD Intolerance to enteral feedings in patients who are critically ill Speed gastric emptying for radiographic exam of small intestines Has been used to improve effectiveness of oral medication if other drugs or the patient’s underlying condition slows gastric emptying

Question 52

Reglan decreases gastric fluid volume, what dose do you give over what time period before induction for desired effects?

Answer 52

10-20 mg IV over 3-5 minutes administered 15-30 minutes before induction of anesthesia results in increased LES tone and decreased gastric fluid volume.

Question 53

why do you not want to give Reglan rapidly IV?

Answer 53

May cause stomach cramping.

Question 54

What are the benefits of gastric emptying potentially/ who benefits patient wise?

Answer 54

Patients who have recently ingested solid food Patients with DM and symptoms of gastroparesis Trauma patients (considered full stomachs) Obese Parturients (especially with esophagitis/heartburn suggesting LES dysfunction and gastric hypomotility

Question 55

Do the effects of reglan on gastric fluid volume alter gastric fluid pH?

Answer 55

does NOT reliably alter gastric fluid pH

Question 56

Will reglan reverse opioid induced inhibition of gastric motility?

Answer 56

ppt states that "may not be reversed with reglan"

Question 57

what drug could you give around the same time as reglan that would make all it's GI benifits be offset?

Answer 57

atropine

Question 58

Obviously giving reglan or other prophylactic drugs such as antacids or H2 antagonists does not replace the need for WHAT?

Answer 58

Proper airway management!

Question 59

Reglan has been shown to decrease chemotherapy-induced n/v and n/v after c-section BUT is not as effective as what other drug class?

Answer 59

5-HT3

Question 60

the antiemetic property of reglan is probably a result of what?

Answer 60

antagonism of dopamine’s effects in the chemoreceptor trigger zone.

Question 61

What two issues accompany the vomiting reflex?

Answer 61

gastric immobility and cephalad peristalsis. | this is what the antiemetic effects of Reglan reverse

Question 62

The antiemetic effects of Reglan are due to what occurring in the GI tract? (like physically what is going on)

Answer 62

increases in LES tone and facilitation of gastric emptying in the small intestines.

Question 63

Gastric stasis induced by what opioid is reversed by reglan?

Answer 63

Morphine

Question 64

Reglan can blunt opioid induced WHAT?

Answer 64

N/V

Question 65

Reglan should not be administered to what three types of patients?

Answer 65

Known Parkinson’s Disease Restless Leg Syndrome Movement disorders r/t dopamine inhibition or depletion.

Question 66

Neurologic dysfunction has been reported r/t pre-op administration of what drug?

Answer 66

Reglan

Question 67

If you antagonize the CNS actions of dopamine with a drug (such as antipsychotic drugs) what may happen?

Answer 67

Extrapyramidal rxn identical to parkinsonian syndrome

Question 68

Akathisia after IV reglan could manifest after surgery in the PACU, what is Akathisia?

Answer 68

feeling of unease an restlessness in lower extremities

Question 69

If Reglan is given in under 3 min what can occur?

Answer 69

abdominal cramping

Question 70

What are some side effects of Reglan related to the heart or blood pressure?

Answer 70

Hypotension, tachycardia, bradycardia, cardiac arrhythmias,

Question 71

What side effects are RARE after a single dose of Reglan?

Answer 71

RARELY after a single dose: Sedation, dysphoria, agitation ,dry mouth, glossal or periorbital edema, hirsutism and urticarial or maculopapular rash.

Question 72

Why shouldn't a patient who has had breast cancer not be treated chronically with Reglan?

Answer 72

breast enlargement, galactorrhea and menstrual irregularities

Question 73

Reglan readily crosses the placenta, have adverse fetal effects been observed?

Answer 73

non have been observed with single doses of Reglan

Question 74

Dopamine will cause inhibition of what mineralocorticoid?

Answer 74

aldosterone secretion.

Question 75

So if Reglan is antidopaminergic and dopamine inhibits aldosterone secretion, then it can be concluded that reglan allows aldosterone to be secreted. So if more than normal aldosterone is being secreted (bc you blocked dopamine which blocks aldosterone secretion) you need to watch for what in said patient?

Answer 75

The possibility of sodium retention and hypokalemia should be assessed in patients who develop peripheral edema during chronic therapy with Reglan!

Question 76

Reglan may increase sedative actions of CNS depressants and the incidence of extrapyramidal reactions cause by certain drugs: Should avoid administering in combination with: (4 answers)

Answer 76

Phenothiazine Butyrophenone drugs Patients with preexisting extrapyramidal symptoms Seizure disorders

Question 77

What issue with the bowels would keep you from giving someone Reglan?

Answer 77

Do not give to suspected or known mechanical obstruction to gastric emptying.

Question 78

What type of psych/depression meds should be avoided with Reglan use?

Answer 78

Avoid in patients taking MOAI or Tricyclic antidepressants.

Question 79

Reglan can decrease the bioavailability of what orally administered med by 25-50%? (think H2 blocker)

Answer 79

cimetidine

Question 80

What types of GI surgeries would you not want to give Reglan to and why?

Answer 80

Do not administer after GI surgery such as pyloroplasty or intestinal anastomosis because it stimulates gastric motility and may delay healing.

Question 81

Remember that with pregnancy you already have decreased plasma cholinesterase activity. Reglan inhibits the effect on plasma cholinesterase activity, thus anyone on Reglan but especially Pregnant women may have prolonged responses to what meds used in anesthesia?

Answer 81

succinylcholine and mivacurium.

Question 82

Metabolism of ester LA COULD be slowed by reglan, why?

Answer 82

reglan induced decreases in plasma cholinesterase activity.