Gastrointestinal Disorders Flashcards
Which of the following is a TRUE statement regarding the treatment of Crohn’s disease or ulcerative colitis?
a) The use of NSAIDs should be avoided
b) Therapy with purine antimetabolites is considered high risk during pregnancy
c) Loperamide is useful for diarrhea in patients with severe disease
d) Sulfasalazine has the least incidence of side effects
e) 5-aminosalicylic acid is the most effective aminosalicylate agents for ulcerative colitis
A. NSAIDs may exacerbate symptoms in both of these conditions.
Purine antimetabolites carry a low risk of teratogenicity, despite conflicting data (page 765, CTC, 7th edn).
Antidiarrheal agents should be avoided in severe disease due to the risk of toxic megacolon.
Sulfasalazine has the highest incidence of side effects, including nausea, headache, rash, haemolytic anemia and hepatotoxicity.
All 5-ASA preparations are equally effective in ulcerative colitis (page 757, CTC, 7th edn).
Which is the BEST response regarding irritable bowel syndrome?
a) Probiotics are very useful in the treatment of irritable bowel syndrome
b) Lifestyle modification is more useful than medication therapy
c) Loperamide 2mg qid is recommended for diarrhea
d) Psyllium and bran should be taken for constipation
e) Pinaverium for spasm is a mainstay of therapy
B. Patients generally benefit more from lifestyle modification, including diet and stress reduction, than from drug therapy.
While there is interest in the use of probiotics in IBS, quality of available products is unreliable and supporting evidence is lacking.
Loperamide should be taken on a PRN basis, not regularly.
For predominant constipation, psyllium OR bran is recommended as fibre sources.
Since “colonic spasm” doesn’t explain IBS symptoms so an antispasmodic, such as pinaverium, dicyclomine or trimebutine, is unlikely to be helpful (page 781, CTC, 7th edn).
Drugs that induce constipation
- Antacids (Al or Ca containing),
- anticholinergic agents,
- anticonvulsant agents,
- antiparkinsonian agents,
- antipsychotic agents,
- antispasmodics,
- bismuth preparations,
- diuretics that cause hypokalemia,
- iron containing products,
- opioids (eg codeine, morphine),
- resins (eg cholestyramine),
- serotonin receptor antagonists (ondansetron),
- sucralfate,
- verapamil.
*Opioid: recommend concomitant rx of stimulant (bisacodyl, senna) or osmotic (lactulose, polyethylene glycol)
For Palliative care opioid use: if laxative not effective, Rx Methylnaltrexone
Drugs that induce diarrhea
(pg 711 CTC)
- Antibiotics,
- cholinergic drugs,
- colchicine,
- laxatives,
- magnesium containing antacids,
- acarbose,
- diuretics,
- Flourouracil,
- orlistat,
- promotility agents,
- Prostaglandins,
- theophylline,
- Metformin
IBS: Caffeine, alcohol, sorbitol, fructose, sucrose,
Red Flags by condition and drug induced conditions: Gastritis/PUD
INT CIMETIDINE
● ↑’s Serum concentrations of: Alprazolam, Amiodraone, Carbamazepine, Carvedilol, Citalopram, Clonazepam, Diazepam, Diltiazem, Flurazepam, Labetalol, Metformin, Metoprolol, Midazolam, Mirtazapine, Nifedipine, Paroxetine, Phenytoin, Propranolol, Theophylline, Triazolam, TCA’s, Warfarin.
● ↓ Bioavilability of: Ketoconazole & Itraconazole
● Can increase pruritis
PPIs CI
Are NOT recommended during pregnancy or breastfeeding d/t lack of evidence
What infection can PPIs contribute to?
Can contribute to C. Difficile
PPIs AE
HA, nausea, diarrhea, rash
INT PPI (Dexlansoprazole, Lansoprazole, Pantoprazole, Rabeprazole)
● May ↓ absorption of ampicillin esters, atazanavir, digoxin, iron salts, ketoconazole
●↓Theophylline levels
●↓ Bioavailability of sucralfate
●↑ Blood levels of tacrolimus
● Conflicting data re interactions w/clopidogrel
INT PPI
(Esomeprazole, Omeprazole)
● May ↓ absorption of ampicillin esters, atazanavir, digoxin, iron salts, ketoconazole
●↓Theophylline levels
●↓ Bioavailability of sucralfate
●↑ Blood levels of tacrolimus
● Conflicting data re interactions w/clopidogrel
PLUS:
● Inhibits CYP2C19 → ↑ levels of carbamazepine, diazepam, digoxin, triazolam, warfarin (may require dose adjustments when adding or removing esomeprazole)
INT RANITIDINE (AVAILABLE OTC)
● May alter prothrombin time when warfarin is used
● ↓ Bioavilability of: Ketoconazole & Itraconazole
● ↑ Absorption of midazolam and triazolam.
● Coadministration with sucralfate decreases absorption
Drugs causing DRUG INDUCED Dyspepsia
(cardinal Sx of PUD)
Bisphosphonates, tetracyclines, CCB, iron salts, opioids, * codeine, NSAiDS, ASA & other antiplatelets (clopidogrel, ticagrelor p. 734 CTC
*H.Pylori infxn
Drugs causing DRUG INDUCED GERD
Anticholinergic agents, beta blockers, calcium channel blockers, theophylline, tricyclic antidepressants
● Anticholinergics
● Barbiturates
● Benzodiazepines (diazepam)
● Caffeine
● Dihydropyridine calcium channel blockers
● Dopamine
● Estrogen
● Ethanol
● Alendronate
● Aspirin
● Iron
● Nonsteroidal anti-inflammatory drugs
● Adapted from Weinberg and Kadish.15
● Isoproterenol
● Narcotics (meperidine, morphine)
● Nicotine (smoking)
● Nitrates
● Phentolamine
● Progesterone
● Theophylline
● Quinidine
● Potassium chloride
Drugs causing DRUG INDUCED
Dyspepsia and Peptic ulcer disease pg. 734
ASA, antiplatelets: clopidogrel, ticagrelor, also warfarin, heparin
SSRIs, corticosteroids, Bisphosphenates, tetracyclines, CCB, iron salts, opioids, esp codeine
NSAIDs** no.1
**Comcomitant use NSAID\ASA+Corticosteroid, antiplatelet (clopid), anticoag (warfarin,heparin), or SSRI = Incrs risk of PUD *Consider use of PPI or misoprostol. PLUS consider changing fr NSAiD to COX-2 inhib for 50-70% reduced risk PUD but risk CV complications P. 738
What makes IBS worse?
Caffeine, alcohol, sorbitol, fructose, sucrose
