Week 2 antiemetics & GI motility (3 of 4) Flashcards
What two anticholinergics can enter the CNS?
Scopolamine and Atropine.
Because these two anticholinergics can cross into the CNS, they can cause what problem?
Scopolamine and Atropine can cause central anticholinergic syndrome.
What do the symptoms of central anticholinergic syndrome look like? (4 answers)
Symptoms range: Restlessness, Hallucinations, Somnolence, Unconsciousness
Which anticholinergic does not cross the BBB?
glycopyrrolate
What drug is the reversal of central anticholinergic syndrome and what drug class is it?
Physostigmine which is a parasympathomimetic, or also called cholinergic receptor simulator agent.
The reversal drug for too much atropine would be?
physostigmine
What is the dose of physostigmine (lipid-soluble tertiary amine) to reverse central anticholinergic syndrome?
physostigmine 15-60 mcg/kg IV. Treatment may need to be repeated every 1-2 hours.
What three Acetylcholinesterase inhibitors are NOT effective antidotes against central anticholinergic syndrome and why?
Edrophonium, neostigmine, and pyridostigmine are not effective antidotes because their quaternary ammonium structure prevents these drugs from easily entering the CNS.
Anticholinergic over dose Produces rapid onset of symptoms characteristic of muscarinic cholinergic receptor blockade: what does that look like?
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)
Why does the body temp increase with use of too much anticholinergic?
↑ 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)
when is increase in body temp. with anticholinergics more likely to happen?
when environmental temp. is increased.
What lab is typically unchanged with anticholinergic over dose (even though you would expect it to be messed up)
ABGs are usually unchanged.
due to CNS stimulation and the impact of an increased physiologic dead space d/t bronchodilation what will also increase?
increased min. ventilation is possible.
What are three fatal events associated with anticholinergic over dose?
Seizures,
Coma,
Medullary ventilator center paralysis
even with therapeutic dose of an anticholinergic drug what can happen in children?
Atropine Fever
What age group is particularly vulnerable to developing life-threatening symptoms after an overdose with an anticholinergic?
small children and infants
Reversal of overdose of anticholinergic in children and infants?
Physostigmine 15-60mcg/kg IV
according to Hammon start on the low end
Why may you need repeated doses of physostigmine?
it is metabolized quickly
What is barrier pressure?
The difference between gastric pressure and lower esophageal sphincter pressure is “barrier pressure.”
What two meds and in what dose decreases lower esophageal sphincter pressure and decreases barrier pressure?
atropine 0.6mg IV or Glycopyrrolate 0.2-0.3 IV
Because atropine and glucopyrrolate decrease lower esophageal sphincter pressure, what is more likely to occur?
GERD
how long does atropine and glcopyrrolate last (in doses that cause increased GERD)
atropine lasts 40min. and glycopyrrolate lasts 60min.
Reglan (metoclopramide) is also known as what type of drug?
Benzamide
Benzamides (such as reglan and domperidone) stimulates GI tract via cholinergic mechanism resulting in: (three answers)
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
Why is domperidone not used in the U.S.?
Domperidone not used in U.S. d/t concern of use in lactating women increases milk production.
What medication would you NOT use on someone who has Parkinson’s and why?
Do not use Reglan bc it is an antidopanergic.
Reglan may have direct effect on what areas of the brain that is good for Nausea?
Reglan may have a direct effect on CRTZ and/or vomiting center b/c of its antidopaminergic effect.
Because of antidopaminergic activity, Reglan should be used with caution if at all in: (name three types of patient)
Parkinson’s disease
RLS
Pts with movement disorders related to dopamine inhibition or depletion.
what kind of body movements CAN Reglan cause?
dystonic extrapyramidal reactions
In pts with no known movement disorders dystonic extrapyramidal reactions occur in less than 1% who are treated chronically or acutely with Reglan?
Chronically
Reports of neurologic dysfunction related to the preoperative administration of what drug?
Reglan
What can happen after a single IV dose of Reglan that could cause a surgery to be cancelled?
Akathisia, a feeling of unease and restlessness in the lower extremities after IV dosing which are sometimes severe enough to cancel surgery.