GI Meds Flashcards
Pharm approach to GERD, always start with TLC then…
Mild (<1wk) = H2 + antacids…fail after 4 wks = PPI
>1wk = PPI
Causes of PUD
H. Pylori
NSAID induced
Stress
Zollinger-Ellison Syndrome
H. Pylori treatment has two therapy options, 1st line is Triple therapy and 2nd line is Quadruple therapy, explain both:
Triple: PPI + clarithromycin + amoxicillin (or metronidazole)
Quadruple - for patients that cannot take clarithromycin: tetracycline + metronidazole + bismuth subsalicylate
Treatment is 14 days Abx, if PUD present, 4-8wks PPI for duodenal ulcers and 8-12wks for gastric ulcers
NSAID induced ulcers tend to be the result of which type of NSAID?
COX-1 selective - increased blood flow to gastric mucosa and kidneys, increased platelet aggregation via TXA2 pathway
Treatment of NSAID-induced ulcers
Stop the NSAID, if you can’t, reduce the dose, switch to APAP/ASA, reserve Celecoxib (Celebrex) as last line b/c of CV risk
Can co-therapy w/PPI or misoprostol
Weak bases that neutralize gastric acid by reacting w/ hydrochloric acid to form a salt and water…rapid onset, short duration, frequent dosing
Antacids - 1st line therapy for intermittent (< twice weekly) symptoms, breakthrough therapy for those on PPI/H2 therapy
Taking these can lead to an accumulation of aluminum or magnesium in renal disease w/repeated dosing
Antacids
Excessive calcium carbonate antacids can lead to…
Metabolic alkalosis and hypercalcemia
AE of magnesium hydroxide (milk of magnesia) antacid…
Osmotic diarrhea
Aluminum hydroxide AEs…
Constipation, caution in renal insufficiency
Simethicone relieves flatulence with a deforming action, but the pt will then do what soon?
Bowel movement
Are H2 receptor antagonists more or less effective than PPIs in healing erosive esophagitis? (Ulcers)
Less
H2RAs have anticholinergic effects, but specifically Cimetidine (the first H2RA) is associated with the rare development of what?
Gynecomastia
Ranitidine, an H2RA, is the preferred H2RA for which route of use?
IV
All PPIs end in which suffix?
Prazole
How long before meals should PPIs be given?
30-60 minutes
What are the 4 possible major AEs associated w/PPIs?
Risk of fracture (hip, wrist, spine)
Hypomagnesaemia
C-diff diarrhea
Community-acquired pneumonia
Also, besides the normal AEs for all meds, may be associated with a higher risk of incident CKD
Sucralfate (mucosal protective agent) is sort of what H2RA/PPIs are tested against in terms of efficacy, but why isn’t it really used itself?
Multiple doses per day, large tablets, need to be separate from meals
What mucosal protective agent is best for prevention of NSAID-induced ulcers, but is rarely used because of high AE profile and pregnancy category X?
Misoprostol
Stimulates mucus secretion, antimicrobial, binds toxins, reduces diarrhea, commonly used EXCEPT IN KIDS IT CAN’T BE (mucosal protective agent)
Bismuth subsalicylate (pepto)
Harmless blackening of stool and darkening of tongue are benign AEs associated with which mucosal protective agent?
Pepto
Prokinetic dopamine antagonist that stimulates motility, anti-emetic, used for GERD, antiemetic in chemo, impaired gastric emptying
Metoclopramide - EXTRAPYRAMIDAL AES (dystopias, akathisia, Parkinsonian features)
Macrolide Abx best used now as a prokinetic in pts with gastroparesis
Erythromycin
What are the Anti-Emetics to know?
5HT3 Phenothiazine Corticosteroids Butyrophenones Benzodiazepines Benzamides Antihistamines/Anticholergic Cannbinoids NK1 Antagonist
Antiemetic class best used for post op N/V, chemo N/V, radiation induced N/V, but can cause QT prolongation
5HT3 Antagonists
THE SETRONS (E.G. ONDANSETRON)
Anti-emetic class best used at the vestibular apparatus to prevent N/V due to motion sickness (all cause some drowsiness/anticholinergic effects)
BEST USED IN PREGNANT WOMEN TOO
1st Gen Antihistamines
E.G. Meclizine, Benadryl, Dramamine, Unisom, Diclegis
Promethazine and Prochlorperazine are two antiemetics that block stuff in the chemoreceptor trigger zone (CTZ), which class are they from?
Phenothiazines
This antiemetic, indicated as a surgical adjunct to block short-term memory and decrease saliva?
Scopolamine
Antiemetic that used to be used as an antipsychotic, now used either for post-op N/V or MC for sedation in endoscopy and surgery often in combo with benzos?
Butyrophenones (Droperidol for example)
Dopamine antagonist that blocks serotonin receptors resulting in anti-emetic action/ acid reducer to prevent N/V from chemo?
Metoclopramide
Causes extrapyramidal effects though
Antiemetic used for apomorphine pre-treatment in Parkinson’s pts?
Trimethobenzamide (Tigan)
In terms of N/V, corticosteroids like dexamethasone and methylprednisone are used for?
Chemo induced N/V with 5HT3 antagonists
Benzos like diazepam and lorazepam are used before chemo initiation to reduce what?
Anticipatory N/V caused by anxiety
Mu opioid agonist that doesn’t cross the BBB used to control mild to moderate non-invasive diarrhea?
Loperamide (Imodium)
Mu opioid agonist with some anticholinergic properties used for refractory diarrhea, but no in young kids or pts with severe colitis?
Diphenoxylate/Atropine (Lomotil)
3 misc agents used to treat diarrhea, and what kind?
Pepto: mild-moderate, traveler’s
Octreotide: GHIH suppression, treatment of tumor-associated diarrhea/HIV associated diarrhea
Lactase enzyme: for lactase deficiency or intolerance
This class of laxatives rapidly moves water into the distal small bowel to treat acute/intermittent constipation pre-op
Osmotic laxatives (magnesium sulfate, magnesium citrate, magnesium hydroxide, sodium phosphate)
What are the cautions in osmotic laxatives?
Electrolyte abnormalities, BB warning for nephropathy with oral products in the sodium one
What it’s he only laxative that you can used with renal failure or when ammonia levels are high?
OSMOTIC LAXATIVES
Polyethylene Glycol (PEG) solutions (GoLyte) used for?
Pre-op colon prep for endoscopic or radiologic procedures (safe in renal/hepatic disease and pregnancy)
Miralax is approved for what type of IBS?
IBS-C (safe in renal, hepatic, pregnancy)
Stimulant laxative, causes after/electrolyte secretion into the bowel, short-term relieves intermittent constipation and long term for PREVENTION OF OPIOID-INDUCED CONSTIPATION
SENNA (BM W/I 6-12 HRS)
This stimulant laxative is used for short term/intermittent constipation or as part of pre-op/colonoscopy bowel prep.
Bisacodyl (Dulcolax)
What is the only real constipation treatment recommended when pregnant?
Stool softeners (stool surfactant agents) - docusate sodium/calcium
Can be used in combo with Senna to prevent opioid induced constipation too
Lubiprostone
Chloride channel activator: stimulates secretion of chloride-rich fluid into the intestinal lumen, USED FOR IBS-C IN WOMEN >18 YRS OLD
Tegaserod (Zelnorm)
Serotonin-4 Partial agonist used for short-term, emergent treatment of IBS-C and Chronic Idiopathic Constipation (CIC) in women <55yrs old where no other therapy exists
EMERGENT ONLY
Linaclotide (Linzess)
IBS-C and CIC
Methylnaltrexone SubQ
Treatment of opioid induced constipation when inadequate response to other treatments
Naloxegol
Treatment of opioid induced constipation in chronic non-cancer pain
First line product for treatment of IBD (aminosalicylate)
Mesalamine
TCA and SSRI use in IBS
TCAs - primarily IBS-D
SSRIs - both IBS-D and IBS-C
Antibiotic derived from rifampin, used to treat IBS-D or traveler’s diarrhea caused by E.coli
Rifaximin
Opioid receptor agonist/antagonist used in which type of IBS?
IBS-D
IBS-D drug, specifically for women, but with a BB warning of ischemic colitis and constipation (5HT3 Antagonist)
Alosetron