GI Flashcards
(42 cards)
Amoxicillin
-Preferred component due to low resistance/toxicity
Clarithromycin
-Increasing resistance
Metronidazole
-alternative for patients allergic to penicllin
Tetracycline
-Used in Bismuth-base quadruple therapy
Bismuth Subsalicylate
-Colloidal therapy where salicylate is absorbed in the stomach and bismuth is secreted in feces
-MOA:
-antibacterial activity of bismuth against H. Pylori and E. coli enterotoxins,
-Forms barrier that protects ulcers from further damage
-anti-secretory and anti-inflammatory salicyclate
Therapy:
-PUD
-Diarrhea: inhibition of intestinal prostaglandin and chloride secretion
-Adverse effects:
-Reyes and salicylism
Magnesium Hydroxide Aluminum hydroxide
- MOA:
- Alkaline compounds that neutralize gastric acid and raise stomach pH, most raise to pH of 5
- Pharm:
- Rapid onset with shot duration of action
- Mg can cause diarrhea due to stimulation of peristaltic activity but Al counteracts this effect
- Ions aren’t well absorbed so don’t cause metabolic alkalosis
- Uses:
- relief of mild symptoms of dyspepsia and GERD
- Can interfere with absorption of other drugs (2hr window)
Cimetidine
MOA: Competitive inhibitor of H2 on basolateral mem of parietal cells –> decreased Gastrin and ACh respons, slower onset than antacids but longer duration (prophylaxis)
USES:
-PUD: Short term promotes healing by decreasing nocturnal acidity
-GERD: Best for nocturnal modest post prandially
-Aspiration Pneumonitis: during anesthesia
Adverse RXN:
-ENDO: blocks androgen receptors –> gynecomastia, impotence, and loss of libido
-CNS: Elderly
-Pneumonia: Incr. bac colonization due to lower pH
Omeprazole (PPI)
- MOA: activated within parietal cells and blocks H/K ATPase, final common pathway for basal and stimulated acid release, effects last until new ATPase are generated
- Pharm: enteric coated, can react with 2C19 (Asians) and dose reduction with hepatic disease
- Uses: PUD and Gerd, Zollinger Ellison, NSAID ulcers in people who continue to use NSAIDS
- ADVERSE: Interactions with, Warfarin, Diazepam, cyclosporine, C. Diff, bone fractures, rebound hyper secretion
Sucralfate
- Sulfated sucrose and AlOH
- MOA: Gel at pH 4 and binds necrotic tissue to form a barrier, take on empty stomach
- USES: Duodenal and stress ulcers, no risk of nosocomial infx
- Adverse: Reduced absorption of other drugs
Misoprostol
- Prostaglandin analog
- MOA: substitutes for PGs when synthesis is inhibited by NSAIDS, reduces acid secretion from parietal cells and promotes bicarb and mucus secretion
- USES: Prevention of gastric ulcers in long term NSAID therapy, NOT PREGNANCY!!!!!!!!!!!
Psyllium
- Bulk forming (group III)
- MOA: Non-digestable agents that swell with H2O increases volume of stool and stim. peristalsis
- Uses: Temp treatment of mild constipation
- Must BE ADMINISTERED WITH A FULL GLASS OF H2O
Docusate Sodium
- Surfactant (Group III)
- MOA: Lowers surface tension allows penetration of H2O
- Uses: Mild Constipation, take with full glass of H2O
Bisacodyl
-Stimulant (group II)
-MOA: Stimulate (via irratation) GI motility and increase H2O and electrolytes within the lumen. (ORAL or ANAL)
-USES: Opioid induced constipation and constipation from slow intestinal transit
ADVERSE: Proctitis with long term use
Magnesium Hydroxide
-Osmotic laxative (Group I)
-MOA: Poorly absorbed salts or sugars which draw H2O in to the stool
USES:
-High Dose: Colonoscopy
-Low Dose: Mild to moderate constipation
-Purging to remove dead parasites
-Adverse RXN: Dehydration and electrolyte imbalance also Mg absorbtion may cause problems with people who have renal impairment
Lactulose
-Prevent hepatic encephalopathy by turning NH3 –> NH4 and trapping it in the stool
Loperamide and Diphenoxylate
-MOA: Agonists for myenteric opiate receptors that reduces secretory activity (delta) and GI motility (Mu)
-PK:
-Loperamide: Poor BBB penetration no abuse
-Diphenoxylate: High oral doses can produce morphine like responses (atropine)
Adverse Effects: Constipation with prolonged use, methylnaltrexone used to treat opiate induced constipation
Ondansetron
- MOA:5HT3 antagonists at peripheral and central site (most effective but efficacy enhanced by corticosteroids)
- PK: Administered IV, long duration of action
- USES: prevent or minimize emesis form CINV and radiation, hyperemesis of pregnancy, NOT effective against motion sickness or DELAYED CINV
Aprepitant
- Blocks NK1 receptors in brain
- Uses: Delayed nausea cisplatin, improves efficacy of other CINV treatments
Black Cohosh
-USE: Treat menopause and PMS
-Active ingredients: Triterpene glycosides and isoflavones (not related to female hormones)
-Efficacy: Probably not (no difference from placebos and inferior to estrogen)
AE: Liver toxicity
Drug Interactions: Potentiates antihypertensives and Oral diabetic medicines
-Avoid during pregnancy and in patients with breast cancer (blue cohosh stimulates uterine contractions
Echinacea
- Use stimulate immune function (URI)
- Active ingredients: echinacosides, polysaccharides, flavonoids
- MOA: INVITRO stimulation of Macrophage activity and t-lymphocyte proliferation but RCT no difference from placebos in treatment and no prevention
- Drug interactions/Contraindications: immunosuppressants, autoimmune disorders
Garlic
- Use: Cholesterol and HTN
- Active ingredient: Organic sulfur compounds, alliin -> allicin (enteric coated)
- MOA: In vitro inhibition of HMG-CoA and reduces platelet aggregation
- Efficacy: May have modest effect but RCT showed no difference in patients with mild hypercholesterolemia but mild blood pressure lowering
- Drug interaction: Aspirin/anticoagulants, insulin/OHAS, saquinivir (incr. clearance)
GInkgo
- USE: Improve memory and concentration, vascular problems
- Active ingredients: flavonoid glycosides
- MOA: increase blood flow to CNS (vasodil.), free radical scavenger, suppresses synth of platelet activating factor
- Efficacy: no difference from placebo in AD and cog decline, RCT showed effects similar to exercise
- Adverse effects: Seeds are epileptogenic
- Drug interactions: Anticoagulants
Ginseng
Use: Tonic to enhance athletic performance
- Active ingredients: ginsenosides
- Efficacy: NOT
- Adverse Effects: Weak estrogenic effects
- Interactions: anticoagulants and insulin/OHA
Ma Huang (ephedra)
-Use Reduce appetite and increase energy, narcolepsy, and nasal congestion
-Active ingredient ephendrine (release of NE)
Efficacy: Well established
Adverse effects” Excessive CNS and CV stimulation
Drug Interactions: CNS stimulants Beta agonist, nasal decongestants, MAOIs, Antihypertensives