Pharm GI Exam 2 Flashcards
(112 cards)
Cause of nausea (Biochemical)
Cause of emesis is a defense mechanism controlled by the medulla oblongata
Receptors of the fourth ventricle in the brain are chemoreceptor zone
the chemoreceptor trigger zone contains dopamine (D2) , 5HT, opioid, ACH and substance P receptors
Stimulation of different pathways lead to emesis
In the final common pathway, substance P activates Nk-1 receptor
Emetic MOA
Drugs selectively bind to receptors in vomiting brainstem
Block signaling pathway
Inhibit stimulation of the GI tract, diaphragm and abdominal muscles
Classes and indications of
H1 antihistamines or antimuscarinics
Vestibular disturbances
vertigo or motion sickness
Classes and indications of
Dopamine receptor antagonists
Most commonly used
Post op nausea
Motion Sickness
Classes and indications of
Glucocorticoids
Chemotherapy induced nausea
Classes and indications of
5-HT3 receptor antagonists
Vomiting caused by acute gastroenteritis
Post op nausea
Go-to for radiotherapy and chemotherapy induced nausea and vomiting
Classes and indications of Neurokinin 1 (NK-1) receptor antagonists
Relatively new class of medication
Radiotherapy and chemotherapy induced nausea and vomiting
Post op nausea
Drugs by type
Antihistamine, anticholinergics
Hydroxyzine Meclizine Scopalamine Cyclizine Trimethobenzamide Dimenhydrinate
Drugs by type
Dopamine receptor antagonists (D2)
Metoclopramide Chlorpromazine Prochlorperazine Promethazine Haloperidol Droperidol
Drugs by type
Serotonin 5HT3
receptor antagonists
-setron Ondansetron Granisetron Dolasetron Ramosetron Tropisetron
Drugs by type
Neuokinin 1 receptor antagonists
-pitant
Aprepitant
Faosaprepitant
Rolapitant
Drugs by type
Other
Cannabinoids
Nabilone
Dronabinol
Nabiximol
Dexamehtasone
Netupitant/palonestetron
Drugs used for motion sickness
Meclizine
(antivert, bonine)
OTC
Meclizine
Antivert (antihistamine)
For motion sickness prophylaxis or vestibular vertigo
25-50mg 1 hour prior to motion
Warnings
Asthma, glaucoma, GI/GU obstruction, Hepatic/renal impairment
Interactions
Alcohol, tranquilizers, sedative-hypnotics potentiate CNS depression
-Setrons
5HT3 receptor antagonists
MOA
Inhibit vomiting due to vagal nerve stimulation particularly due to chemotherapy, radiotherapy, anesthesia
Blocks the serotonin receptors (5HT3) in VC, CTZ, and peripheral 5HT receptors
Ondansetron
Zofran (5ht3 receptor antagonist)
Contra
Serotonin syndrome possible with SSRI’s, SNRI’s etc
May antagonize tramadol
Adverse
Diarrhea, HA, Fever, Constipation, Fatigue, transient blindness, Serotonin syndrome (discontinue)
Metoclopromide
Reglan (dopamine 2 receptor antagonist)
Contra
History of tardive dyskinesia or dystonic reaction
Warning
Tardive dyskinesia
Promethazine
Phenergan
For motion sickness or perioperative nausea/vomiting
Adverse
Drowsiness, lowered seizure threshold, Cholestatic jaundice, anticholinergic and EP effects
Phenothiazine??
Aprepitant
Emend
Substance P/NK1 receptor antagonist
Small intestine disorders
Appendicitis
Celiac’s
Intussusception
Obstruction
ABX for non perforated Appendix
Cefoxitin or Cefotetan 2g IV once
or
combo of cefazolin 2g <120kg, 3g >120kg plus
Metronidazole 500mg IV
Or if inpatient and allergic to penicillin
Clindamycin plus one of the following
ciprofloxacin, levofloxacin, gentamycin, aztreonam
6 elements in the management of patients with celiac disease
Consult dietician Education about disease Lifelong adherence to a gluten free diet ID and treat nutritional deficiencies Access to an advocacy group Continuous long term follow up by a multidisciplinary team
Celiacs
abnormal small intestinal mucosa that improves morphologically when treated gluten free diet and relapses when gluten is introduced
Celiac nutritional tests
Test for deficiencies Vitamins ADE (fat soluble) copper zinc carotene folic acid ferritin iron
Thiamine, B6, mag, selenium may also be deficient