This is a draft cheat sheet. It is a work in progress and is not finished yet.
Manage peptic ulcer
1. Antacids |
1st line. Neutralize acid & raise gastric pH. |
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Uses: PU, gastritis, reflux esophagitis |
Rapid acting: MgOH, MgO & CaCO3
Intermediate acting: Magalderate & MgCO3
Slow acting: Mg silicate & Al compounds. |
CaCO3: non-systemic Ca that causes acid rebound. |
Bismuth subsalicylates:
MOA: glycoprotein-bismuth complex with mucus (protective barrier)
Stimulates epidermal growth factor which enhances ulcer healing. |
NaHCO3: systemic antacid. |
Gastric antacid mixtures benefits:
1. combine rapid & slow acting components to get rapid onset with sustained action.
2. Decreases dose and SE of single agents
3. Use agents that antagonize each other. |
Manage peptic ulcer
2. H2 receptor antagonist |
MOA: inhibits acid and gastrin stimulated secretions. |
Cimetidine
has many SE: impotence, gynecomastia, headache, dirrahea, muscle pain, short acting and CYP 450 inhibitor (D-D interactions) |
Ranitidine
more potent than cimetidine.
has furan ring. |
Famotidine-Nizatidine-Roxatidine |
Endogenous substances stimulating gastric acid secretion: ACh-Gastrin-Histamine-Calcium
Uses of H2RB:
1. PU
2. Benign gastric ulcer
3. Reflux esophagitis
4. Hypersecretory conditions.
Manage peptic ulcer 3. PPI
Omeprazole |
Lansoprazole |
Esomeprazole |
Enteric-coated granules. |
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S-enantiomer of omeprazole. found in racemic omperazole. |
ttt of gastric & duodenal ulcers. |
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More active due decreased interindividual variation in bioavailability. |
Prodrugs.
Irreversibly (covalently) inhibit the proton pump (H/K ATPase) which stops proton pumping into gastric lumen.
Manage peptic ulcer
4. Sucralfate (chemical complex) |
5. Prostaglandins cytoprotective drugs |
Adjuvant therapy with only local action in GIT. |
Inhibit gastric acid & pepsin secretions. |
MOA: forms a protective barrier around ulcer site. |
Misoprostil
Semisynthetic deriv. from PGE1 , but more stable & selective due to 16-methyl and 16-hydroxy gp. |
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- increase GI mucus and bicarbonates. |
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- Used with NSAIDs for gastric and duodenal ulcer ttt. |
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Misoprostol
anti-secretory & cytoprotective. |
Laxatives
Stimulant laxatives |
Saline laxatives |
Bulk-forming laxatives |
Fecal softners |
Increase perstalisis & effect on water reabsorption and secretion. |
Mg, sulfates, phosphates and tartrates salts.
-Mg citrate-Mg sulfate-Dibasic sodium phosphate. |
Polysaccharides that are only partially hydrolyzed. (Plantago seed, Polycarbophil) |
Surfuctants or wetting agents. (Docusate soduim) |
Anthraquinone laxatives: Senna, Cascara |
MOA: (work by hyperosmolarity)
Cations and anions that are not absorbed from GIT and in a hypertonic solution, draw water from tissue into intestine-> perstalisis-> watery stool. |
MOA: The undigested portions of the polymer are hydrophilic, so they swell and form a viscous solution or gel-> perstalisis-.>soft gelatinous stool |
Non-absorbable & non-toxic. |
Diphenylmethane: Bisacodyl, phenophathalein |
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MOA: lower surface tension of stool to allow intestinal fluid penetration--> soft stool. |
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uses: for geriatrics. |
Anti-diarrheal agents
Loperamide HCl |
Diphenoxylate HCl |
Synthetic . |
Synthetic congener of meperidine (opioid analog). |
For acute non-specific diarrhea. |
Slows intestinal motility. |
MOA: works on opioid receptors |
Uses: travellers diarrhea. |
Antiemetics
Anti-psychotics |
Antihistamines |
Anticholinergics |
Cannabinoids (THC) |
Metclopramide
blocks D receptor of CTZ. |
Domperidone
increases gastric motility which decreases nausea. |
Phenthiazines & butyrophenones |
Diphenhydramine |
combined with scopolamine and amphetamine. |
Dronabinol |
Diphenidol
Depresses vestibular apparatus. |
Ondansetron
5-HT3 antagonist.
used for CINV. |
Act on CTZ. |
treat motion and morning sickness. |
Treat motion sickness. |
for N/V in cancer chemotherapy. |
Adsorbants
Activated charcoal |
Kaolin |
Pectin |
Treated residue to increase adsorptive power. |
hydrated aluminium silicate |
Natural purified carbohydrate. Consists of partially methoxylated polygalacturonic acid. |
Uses: Antiflatulence and antidote |
Alone or a mixture with pectin. |
Uses: protectant agent for diarrhea in infants and children |
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Uses: for food poisoning diarrhoea or dysentery. |
Inert powders that adsorb gas, toxins & bacteria.
Miscellaneous GI compounds
Cholestyramine resin |
Lactulose |
Simethicone |
Strong basic anion exchange resin with styrene-divinyl benzene copolymer with a quaternary ammonium. |
Syrup to reduce blood ammonia levels. |
Mix of fully methylated linear siloxane polymer of repeating units. |
MOA: Bile acid sequesterant. |
MOA: its poorly absorbed and converted in GIT into acids that neutralize ammonia. |
Uses: antifoaming agent for distention, anti-spasmodic, antiflatulance (for kids). |
Chelating agent so D-D interactions occur and affects ADEK vit. absorption. |
Uses:Laxative, Portal-systemic encephalopathy. |
Uses: high cholesterol managmenr |
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