GI Flashcards
Ranitidine
Histamine 2 antagonist, antiulcer
use: PUD, gastritis induced by stress, and GERD
how: H2 antagonist competitively inhibit histamine at the gastric parietal cell H2 receptor which leads to less gastric acid and secretion at the h+/k+ proton pump. allows for healing of the ulcer and decreases discomfort
ci: lactation, gynecomastia, safe in pregnancy
interactions: antacids my inhibit absorption, may disrupt warfarin clearance- watch for bleeding
se: headache, nausea, vomiting, diarrhea, contipation, abdominal discomfort
Esomeprazole
PPI, gastric acid secretion inhibitor
use: GERD, PUD, H. pylori, prevent gastrointestinal bleeds with NSAID use, Zollinger-Ellison syndrome
interactions: amoxicillin may increase levels, increases levels of diazepam, phenytoin and warfarin
take one hour before meals or decreased absorption of ppi
se: headache, gas, indigestion, abdominal pain, malabsorption of B12, may increase risk of hip, wrist andd spinal fractures and the development of C.diff
to eradicate H. pylori: ABC of TreatMent Amoxicillin Bismuth Clarithromycin Tetracycline Metronizadole
Misoprostol
Prostaglandin E1 analogues, endocrine metabolic agent, anti ulcer agent
use: Prevention of NSAID induced ulcers in the elderly,
how: inhibits gastric acid secretion by direct action on the parietal cells by binding to the prostaglandin receptor. This increased bicarbonate secretion and decreases the volume and pepsin content of the gastric secretions, protects the tight junctions between epithelial cells and increases the thickness of the mucus layer
ci: Pregnancy X
any food will decrease absorption rate of drug
Interactions: magnesium antacids may increase risk of diarrhea, misoprostol may enhance the therapeutic effect of carbetocin, do not use together!!
se: menstrual irregularities, Abortion, abdominal cramps, diarrhea (MAAD)
Sucralfate
Pepsin inhibitor, GI protector, anti ulcer
use: duodenal and stress ulcers
how: compound that promotes the healing of duodenal ulcers - forms a barrier around that helps to both physically protect it but enhance prostaglandin synthesis to enhance the mucosal barrier
interactions: needs an acidic environment to work, do not take with antacids, H2 blockers, or PPI
se: constipation
Dicyclomine
Antispasmodic, muscarine receptor antagonist
antidiarrheal
use: IBS
how: blocks parasympathetic stimulation of intrinsic nervous system, reduces gastrointestinal tone and motility, directly relaxes GI smooth muscle
ci: obstruction of GI, UC, myasthenia graves, glaucoma, reflux esophagitis, breast feeding, infants less than 6 months
interaction: additive anticholinergic effect with antihistamines
Loperamide
antidiarrheal, opioid analogue, piperidine derivative
use: mild to moderate acute diarrhea, IBD chronic diarrhea, decreases volume of ileostomy drainage
how: activates opioid receptors in GI smooth muscle, leads to inhibition of acetylcholine release resulting in decreased gut peristalsis
ci: bloody diarrhea, high fever, infectious diarrhea, pseudomembranous colitis, abdominal pain without diarrhea, acute UC, under 2 yo
interaction: additive effects with CNS depressants like kava chamomile and valerian
se: constipation, drowsiness
Bismuth subsalicylate
antimicrobial, anti inflammatory (bismuth)
antisecretory (salicylate)
use: nausea, heartburn, indigestion, upset stomach, diarrhea, H. pylori
how: antidiarrheal by stimulating absorption of fluid and electrolytes across the intestinal wall (anti-secretory action), when hydrolyzed to salicylic acid it inhibits synthesis of prostaglandin responsible for intestinal inflammation and hyper motility, also binds to E. coli, has weak antacid properties
ci; aspirin or other salicylate sensitivity, pregnancy and lactation
interactions: potentiates warfarin, may decrease absorption of tetracycline
se; nausea, may cause BLACK TONGUE AND BLACK TARRY STOOLS
Bisacodyl
laxative, stimulant laxative
use: acute constipation, before colonoscopy, constipation due to opioid (with docusate!)
how: inhibits colonic fluid reabsorption, increases luminal pressure and stimulates peristalsis
ci: obstruction, severe impaction, appendicitis or acute surgical abdomen, vomiting, rectal bleeding, gastroenteritis
interactions: do not give antacids or milk within 1 hour of taking this drug
se: cramping, nausea, fluid and electrolyte depletion
Docusate
stool softener, laxative
surface active DETERGENT agent, surfactant
use: prevent constipation, use together with bisacodyl to treat opioid constipation, give as rectal enema for fecal impaction
ci: obstruction, undiagnosed abdominal pain, prolonged use
interactions: increases mineral oil absorption and may cause toxicity
se: abdominal cramping, diarrhea, excessive bowel activity, throat irritation, bitter taste
Sodium Phosphate enema
Saline laxative, phosphoric acid salt
use: colonoscopy, natural cathartic laxative, constipation
how: osmotic, draws water into the lumen of the small intestine which produces dissension and peristalsis and evacuation
ci: caution with children 2-11 yo, or elderly patients with comorbidities, do not use laxatives when nausea, vomiting or severe abdominal pain is present, caution with renal impairment or ascites
se: acute renal failure, hypocalcemia, hypernatremia, hyperphophatemia
Sulfasalazine
GI tract antiinflammatory, anti rheumatic,
salicylate sulfonamide
analgesic
use: Crohn’s, UC, rheumatoid arthritis
ci: SULFA DRUG OR SALYCILATE allergy, intestinal or urinary tract obstruction, porphyria, under 2, Pregnancy and lactation (folic acid)
interactions: reduced absorption of folic acid and digoxin
se: anorexia, headache, nausea, vomiting, gastric distress, apparently reversible oligospermia
Metoclopramide
antiemetic, gi stimulant
dopamine receptor antagonist
use: nausea and vomiting with chemo and radiation, GERD (2nd line choice)
how: antagonist of D2 dopamine receptors and blocks the vomiting reflex pathway, it also enhances the motility of the upper GI tract and increases gastric emptying without affecting secretions, increased duodenal peristalsis , lower esophageal sphincter tone
ci: GI hemorrhage, parkinson, perforation, epilepsy, pheochromocytoma
other drugs causing extrapyramidal symptoms (phenothiazine, butyrophenones)
interactions: increased sedative effects with CNS depressants, synergistic toxicity with other dopamine antagonists, GI effects antagonized by antimuscarinics and opioids, reduced absorption of digoxin, increased risk of serotonin syndrome with SSRI
se: Mental effects: agitation, anxiety, insomnia, DROWSY
Extrapyramidal effects: dystonia, tardive dyskinesia (permanent), torticollis, facial spasms, urinary retention, tetanus like rxns
Prochlorperazine
antiemetic, anxiolytic, antipsychotic
piperazine phenothiazine
use: sever nausea and vomiting, anxiety, psychosis, agitation with dementia
how: antidopaminergic effects
ci: coma, severe CNS depression, concurrent use of large amounts of CNS depressants, poorly controlled seizure disorder, subcortical brain damage, severe hypertension, severe cardiovascular disease, lactation, children under 2, pregnancy
interactions: additive anticholinergic effects with antihistamines, TCAs and dopamine agonists
Angelica sinensis, Hypericum perforated: photosensitivity Piper methysticum: dystonic reaction
se: somnolence, respiratory depression, hypotension, extrapyramidal symptoms, photosensitivity
Ondansetron Hydrochloride
antiemetic
selective serotonin receptor antagonist
use: nausea and vomitinw tie chemo, surge, radiation
off label for hyperemesis gravidarum
how: acts to block 5-HT3 receptors in chemoreceptor trigger zone in brain stem
ci: use cautiously with liver failure
interactions: decreases effectiveness of cyclophosphamide, a chemo drug that suppresses the immune system
se: headache, dizzy, constipation, increased LFT and fever are less common, rarely arrhythmias and serotonin syndrome
