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ch. 50 Pharm
Acid Controlling Drugs
Question | Answer |
---|---|
What does the stomach secrete | HCI, bicarbonate, pepsinogen, intrinsic factor, mucus, prostaglandins |
What are the three glands of the stomach | cardiac, pyloric, gastric(largest in # and most important) |
What are the cells of the gastric gland | parietal, chief, mucous, endocrine, enterochromaffin |
What do parietal cells do | produce and secrete HCI primary site for acid controller drugs "Riot" spitting acid |
What are chief cells | secrete pepsinogen, proenzyme Pepsinogen = pepsin in acid, breaks down proteins |
what are mucous cells | surface epithelial cells, protect mucus coat and self digestion of HCI |
Where does hydrochloric acid come from? | secreted by parietal cells with food stimulation. pH 1-4 Also stimulated by fatty meals, alcohol, emotional stress |
Acid related disease is caused by what | imbalance of three cells of gastric gland and secretions; hyperacidity, sour stomach, indigestion, acid stomach |
What is PUD GERD H pylori | PUD- peptic ulcer disease GERD- gastroesophageal reflux disease H pylori: bacteria in GI 90% of duodenal ulcers, 70% gastric ulcers, detected by serum antibody tests, antibiotics |
What are three types of acid controlling drugs | antacids H2 antagonists proton pump inhibitors |
what is MOA of antacids | neutralize stomach acid, but don't prevent overproduction of acid secrete mucus, bicarbonate, prostaglandins(prevent activation of proton pump) |
what pH does the antacids get reduced to | pH 1.3 - 1.6 decr 50% of gastric acid 1.3-2.3 neutralizes 90%, decr pain |
antacids used alone or in combo are | aluminum salts, Mg salts, Ca salts, Na bicarbonate |
what does Aluminum salts do | gel your poop, good for renal failure Basaljel, AlternaGEL, Maalox, Mylanta, Di-Gel |
What does Mg salts do | diarrhea, not for renal failure b/c failing kidney can't excrete extra Mg, so accumulates Milk of Mag, (Mylanta, Maalox-alum and Mg) |
What do Ca salts to | constipation, not for renal disease ex: Tums (Ca carbonate) |
What does Na bicarbonate do | quick onset, short duration, can cause metabolic alkalosis, not for renal or HTN ex: baking soda |
How do antiflatulents work | alters elasticity of mucus, breaking bubbles. Ex: activated charcoal, simethecone (Mylicon drops) |
what are adverse reactions to Alum & Ca Mg: Ca Carbonate: | Alum/Ca - constipation Mg- diarrhea Ca carbonate- gas/belching |
What is chelation and how does it apply to antacids | "claw of lobster" grabs/binds and reduce drug absorption, produces insoluble complexes |
Incr stomach pH does what to GI drugs Decr stomach pH does what incr urine pH/decr? | incr stomach pH = basic/alkaline, incr absorption of basic drugs decr stomach pH = acidic, incr absorption of acidic drugs incr urine pH- incr excretion of pH drugs decr uring pH- decr excretion of basic drugs "Like pH loves like pH" |
Which pts should not use antacids with high Na contents | HF or HTN pts |
how can antacids react with other drugs | may cause premature dissolving of enteric coated tabs give 1-2 hrs after antacid |
what is precautionary with long term antacid use | May mask symptoms of serious underlying diseases, i.e. bleeding ulcers, cancer |
List some Histamine type 2 (H2) antagonists | tagamet, axid, pepcid, zantac |
what is MOA of H2 antagonists | block histamine at H2 receptors of producing acid producing parietal cells, decr H ions |
what are some adverse effects of tagamet | impotence and gynecomastia (male breast enlargement) |
what can decr H2 blockers | smoking |
How do proton pump inhibitors work | Proton pump, which are parietal cells that release H ions(protons) during HCI production, stops this action. Produce achlorhydria. H2 and antihistamines don't. |
what is achlorhydria | all gastric acid secretion temp blocked binds to H+/K= ATPase enzyme |
what are examples of proton pump inhibitors | Prevacid, Prilosec, Aciphex, Protonix, Nexium "prazole, the pump inhibitor" |
what do proton pump inhibitors treat | GERD, erosive esophagitis, short term duodenal/benign gastric ulcers, Zollinger-Ellison syndrome, H Pylori |
what is only proton pump inhibitor available in parenteral adm | Pantoprozole "Oddie needs IV since he's panting so much" granules can be given in NG tube of 16g or it can clog, can mix with applesauce |
when do proton pumps work best | 30-60 min. before meals |
Name three other drugs | sucralfate(Carafate), misoprostol(Cytotec), simethicone(Mylicon) |
Sucralfate (Carafate) help best wtih | stress ulcers, PUD, protect from pepsin(makes ulcers worse), binds w/ phosphate and used in renal failure to reduce phosphate levels |
How does misoprostol (Cytotec) help | cytoprotective, protect gastric mucosa from injury, promote cell regeneration ALSO used to induce labor |