Term
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Definition
Class: suppress gastric acid, PPI
Mechanism: inhibit H/K ATPase, prodrug (absorbed, to parietal cell, in canaliculi, acid activates), binds irreversibly to -SH group
Indication: promote healing of gastric ulcers, GERD, hypersecretory dz (Zollinger-Ellison synd), reduce risk of duodenal ulcer recurrence assoc. w/ H. pylori
Adverse Effects: hypergastrinemia (trophic factor), decreased B12 absortion, INHIBITION OF CSOME CYP450 (warfarin, phenytoin, benzos, increased), acid rebound
Pharmacokinetics: half life 1-2hr, duration of action 24-48 (req. pump resynthesis), hepatic oxidative metabolism by CYP2C19 and CYP3A4, renal excretion of metabolites |
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Term
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Definition
Class: suppress gastric acid
Mechanism: H2R antagonist, reversible binding, suppress basal acid secretion of parietal cells
Effects: most effective against nocturnal secretion, also (less) effective against acid stimulated by feeding, dose related effects,
Indication: promote healing of gastric and duodenal ulcers, uncomplicated GERD, prophylaxis of stress ulcers (ICU)
Adverse Effects: gynecomastia, impotence (displaces DHT), inhibits P450 metabolism of estrogen; tolerance, acid rebound
Drug Interactions: HUGE inhibition of P450
Pharmacokinetics: onset 1hr, peak 1-3hr, duration 6-10hr |
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Term
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Definition
Class: suppress gastric acid
Mechanism: PGE analog, binds EP3 receptors on parietal cells and inhibit acid secretion [MAIN EFFECT]; stimulates secretion of mucin and bicarb (cytoprotective), increases mucosal blood flow; PRODRUG
Indication: prevention of NSAID ulcers
Adverse Effects: diarrhea (30%), exacerbation of IBD, can induce abortions
Pharmacokinetics: extensive first-pass esterification to ACTIVE METABOLITE, onset 30min, peak 6-90min, duration 3hr, renal elimination, t1/2 20-40min |
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Term
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Definition
Class: mucosal protectant
Mechanism: sulfated polysaccharide with aluminum hydroxide, cross-links in acidic pH and yields viscous sticky polymer that adheres to epithelial cells and ulcer craters, prevents hydrolysis of mucosal proteins by pepsin
Indication: (not used for peptic ulcer anymore), inflammatory conditions that don't respond to PPI, stress ulcers
Adverse effects: constipation (2%), interfere with gastric absorption of drugs |
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Term
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Definition
Class: antacid
Mechanism: neutralize acid, raise gastric pH from 1 to 3.5
Benefits: highly effective, inexpensive
Disadvantages: short duration, deliver 12mEq of sodium per gram, causes alkalosis with excessive use, produces CO2 (gas) |
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Term
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Definition
Class: antacid
Mechanism: neutralize acid, raise gastric pH from 1 to 3.5
Benefits: rapid onset, long (30min) duration, provides calcium
Disadvantages: locally (constipation, acid rebound, gas), systemic (elevated plasma calcium concentrate, alkalosis) |
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Term
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Definition
Class: antacid
Mechanism: neutralize acid, raise gastric pH from 1 to 3.5
Disadvantages: local (diarrhea), systemic (increase plasma Mg in patients with impaired renal fx --> CNS toxicity) |
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Term
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Definition
Class: antacid
Mechanism: neutralize acid, raise gastric pH from 1 to 3.5
Disadvantages:
local (constipation)
systemic w/ chronic use/renal impairment (neurotoxic from high Al-, myopathy weakness)
systemic w/ chronic use/nml kidneys (reduce phosphate reabsorption in gut, lower plasma phosphate --> mobilization of bone --> weaken bones) |
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Term
| magnesium-aluminum combination |
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Definition
Class: antacid
Mechanism: neutralize acid, raise gastric pH from 1 to 3.5
"Benefits": neutralize acid with fewer side effects, constipation and diarrhea should cancel
Disadvantages: still see C/D, exposure to Mg and Al, even bigger problem if renal fx decreased |
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Term
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Definition
Class: prokinetic
Mechanism: D2 receptor antagonist, enhances ACh release at GI muscle by blocking DA's inhibition of ACh release, inhibits emesis via CTZ in CNS and stomach
Indication: gastroparesis (delayed gastric emptying), N and V from dysmotility
Adverse Effects: may enhance prolactin release |
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Term
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Definition
Class: prokinetic, antiemetic
Mechanism: 5HT4R agonist, 5HT3R antagonist D2R antagonists; increases tone of LES, ++ antral and small intestine contractions, facilitates gastric emptying, no affect on lower GI motility; anti-emetic via block D2R in CTZ
Indication: gastroparesis (delayed gastric emptying), postop ileus (bowel obstruction), N and V from GI dysmotility
Adverse Effects: extrapyramidal effects (inhibition of D2 in CNS), tardive dyskinesia (repetitive movements) |
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Term
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Definition
Class: antiemetic
Mechanism: H1R antagonist, depresses labyrinth (inner ear) excitability (@ brainstem)
Indication: motion sickness
Adverse Effects: CNS depression |
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Term
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Definition
Class: antiemetic
Mechanism: 5HT3R antagonist selective, blocks receptors in CTZ
Indication: N&V of chemo/radiation, post-op N&V
Adverse Effects: allergy, constipation, diarrhea, fever, HA
Pharmacokinetics: hepatic elim, t1/2 6hrs, longer duration |
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Term
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Definition
Class: antiemetic
Mechanism: CB1 agonist, delta-9-tetrahydrocannabinol (THC), stimulates receptors in or around emesis center,
Indication: emesis, stimulation of appetite in AIDS and anorexia
Adverse Effects: central sympathomimetic (tachycardia, conjunctival injection), highs, paranoid reactions, abstinence syndrome (irritable, insomnia, restlessness)
Pharmacokinetics: highly lipid soluble, active and inactive metabolites (long peresistance), readily absorbed p.o., extensive first-pass, highly ppb, large Vd |
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Term
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Definition
Class: antidiarrheal
Mechanism: subsalicylate suspened in mix of magnesium aluminum silicate clay, in stomach acid forms bismuth oxychloride and salicylic acid, bismuth travels through intestins, but SA absorbed, "anti-secretory, anti-inflammatory, anti-bacterial"
Indication: diarrhea, traveler's diarrhea, H. pylori combo treatment
Adverse Effects: blackens stool, darken tongue (due to rxn with bacterial sulfides); |
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Term
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Definition
Class: antidiarrheal, opioid
Mechanism: mu R --> decrease intestinal motility, delta R --> decrease intestinal secretion, mu and delta Rs --> increase intestinal absorption; 50x more effective than morphine for diarrhea, poor CNS penetration
Indication: OTC diarrhea tx
Adverse Effects: OD --> CNS depression, children more sensitive to CNS effects
Contraindication: active IBD in colon |
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Term
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Definition
Class: laxative
Sources: aloe, rhubarb, cacara segrada, senna
Pharmacokinetcs: onset 8-12hr (Activated in colon)
Adverse Effects: cramping, induce inflammation, may cross into breast milk, lazy bowel syndrome w/ abuse of it |
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Term
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Definition
Class: laxative
Pharmacokinetics: prodrug that requires hydrolysis
Adverse Effects: bowel inflammation, |
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Term
| what determines efficacy of antacid |
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Definition
particle size
tablets less effective than liquids |
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Term
| drug interactions of antacid |
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Definition
increases dissolution and absorption of weak bases
increases dissolution of enteric coatings
decreases absorption of drugs (penicillin, tetracycline)
alters urinary excretion of drugs (alteration of urinary pH) |
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Term
| treatment for H. pylori infection |
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Definition
PPI or H2 antagonist + amox + clarithromycin + metronidazole
PPI + tetracycline + bismuth subsalicylate + metronidazole
7d treatment course |
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Term
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Definition
Class: prokinetic, motilin-mimetic
Mechanism: mimics motillin, enhances gastric emptying by increase in coordinated contractility of smooth muscle of upper GI, no significant effect on lower GI
Indication: diabetic gastroparesis, ileus (high doses)
Adverse Effects: tolerance |
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Term
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Definition
chemoreceptor trigger zone
emesis center of brain
small bilateral area on floor of 4th ventricle near area postrema
receptors for 5HT, DA, and opioids
inhibited by domperidone and blocks emesis |
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Term
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Definition
solitary tract nucleus
emesis center of brain
receptors for histamine, ACh, and 4HT |
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