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Pharmacokinetics module 8.
Save Peptic Ulcer Disease - ANSWERCaused by h pylori, NSAID PUD treatment - ANSWER-Discontinue use of NSAIDs
- Antibiotics- treat H. pylori
- OTC Antacids (For right now pains)- Maalox, Tums
- H2 Receptor blockers- reduce acid secretions (works SLOW); Ranitidine,
- PPI- inhibit acid production (creates less acid to calm stomach); omeprazole, pantoprazole,
- Cryoprotective agents- bind to mucosal layer and form a protective barrier; Sucralfate
- Vagotomy; if severe, surgical cutting of vagus nerve to reduce acid secretions to the stomach You have diagnosed your patient with a gastric ulcer that's not related to h pylori. You have decided to use cimetidine (Tagamet) 800mg pi at bedtime for 8 weeks. You choose cimetidine because you understand that the mech of action is best defined as - ANSWERSuppresses acid secretion by blocking H receptors in parietal cells H2 blockers - ANSWERblock H2 receptors in the stomach to prevent the release of acid to treat heartburn, peptic ulcers, and GERD Promotes healing of gastric and duodenal ulcers in 8-12wks
Prophylaxis PPI - ANSWERConverts to active form in parietal cells of stomach Active form causes irreversible inhibition of enzyme that generates gastric acid Tx: duodenal and gastric ulcers, erosive esophagitis, GERD A pt with PUD is otherwise healthy with no active bleeding but is h pylori +. Does not smoke or excessively drink. Nkda. Which drugs will you prescribe - ANSWERAmoxil, clarithromycin, omeprazole H. pylori tx triple therapy - ANSWERBID——>amoxicillin, clarithromycin, PPI 2 abx minimum (amoxil, clarithromycin, tetracycline, flagyl, tinidazole) Avoid what with flagyl? - ANSWERalcohol Drugs causing disulfiram like reaction - ANSWER"Sorry Pals Cannot Go Mingle" Sulfonylureas (1st gen), Procarbazine, Cephalosporins (cefotetan, cefoperazone), Griseofulvin, Metronidazole Phenergan - ANSWERContraindicated in kids less than 2yo (respiratory depression and local tissue injury)
Blocks 5-HT3 receptors resulting in firm stool and decrease in urgency and frequency of defecation Can cause constipation BLACK BOX: ischemic colitis (rectal bleeding, bloody diarrhea, abd pain) Which of the following statements distinguishes severe tx options for UC? - ANSWERGlucocorticoid, cyclosporine, and vedolizumab (entyvio) Crohn's disease - ANSWERa chronic autoimmune disorder that can occur anywhere in the digestive tract; however, it is most often found in the ileum and in the colon ulcerative colitis (UC) - ANSWERdisease characterized by inflammation of the colon with the formation of ulcers, which can cause bloody diarrhea A pt is newly dx with IBD. Multiple meds may be needed for tx. Which statement is most accurate - ANSWERDrug therapy aims to control inflammation but does not cure the disease 4 drug classes for IBS - ANSWERAntispasmotics Bulk forming agents Antidiarrheals TCAs 5 major drug classes for IBD - ANSWER 5 - aminosalicylates
Glucocorticoids Immunosuppressants Immunomodulators Abx Senna can cause what in infants? - ANSWERElectrolyte imbalance Why should laxatives be used cautiously in pregnancy? - ANSWERCan induce labor May be excreted in breast milk Which of the following meds is considered appropriate for acute uncomplicated cystitis in a healthy non pregnant adult female with nkda - ANSWERNitrofurantoin Trimethoprim-sulfamethoxazole Fluoroquinolones and uncomplicated utis - ANSWERShould be avoided unless there are no other tx options Are oral abx as effective as iv abx for UTI and pyelonephritis? - ANSWERYes When should iv abx be used in children to tx uti? - ANSWERChild appears clinically toxic Bacteremia or sepsis suspected The child cannot tolerate oral abx
Gingko (increases bleeding risk) Licorice: lowers warfarin levels St. John's wort: lowers warfarin levels Major interactions with warfarin: cannabis, chamomile, cranberry, grapefruit, lycium, red clover, and St. John's wort CAM that affect digoxin - ANSWERLicorice: increases digoxin effects St. John's wort: lowers blood concentrations of digoxin Ginseng: may falsely elevate digoxin levels CAM possible effects on cardiac meds - ANSWERSt. John's wort: induced CYP3A4, LOSS of therapeutic effects Garlic: significant anti platelet effects and risk of bleeding Ginkgo balboa: increases bleeding risk Ginger root: increases bleeding risk Coq-10: May decrease the effectiveness of warfarin; increased blood clot risk
Cranberry juice: increased risk of bleeding Fever few: increased risk of bleeding Bulk forming laxatives - ANSWERPsyllium (Metamucil) Surfactant laxatives - ANSWERdocusate sodium (Colace) Group III Surfactant action soften still by facilitating penetration of water and causing secretion of water and electrolytes into intestine, may also inhibit fluid absorption Stimulant laxatives - ANSWERBisacodyl (Dulcolax), senna (group II) Castor oil (group 1 laxative) Stimulate peristalsis; soften feces by increasing secretion of water and electrolytes into the intestine and decreasing water and electrolyte absorption (colon and small intestine) Osmotic laxatives - ANSWERmagnesium hydroxide, magnesium citrate, polyethylene glycol, lactulose
Osmotic laxative and sodium phosphate interaction can cause what? - ANSWERAcute renal failure Lactulose - ANSWERosmotic laxative; removal of ammonia in the body (Used in pts with portal htn and hepatic encephalopathy) Lubiprostone (Amitiza) - ANSWERChloride channel activator, leads to increased fluid and peristalsis CIC, OIC, IBS-C (in adult women) AE: nausea Self-resolving Dyspnea Linaclotide (Linzess) - ANSWERguanylate cyclase-C agonist (increases chloride and bicarbonate secretion into the intestinal lumen, increasing the speed of GI transit and reducing abdominal pain) Used for CIC and IBS-C Pathogenesis of Peptic Ulcers - ANSWER1.-h pylori 2.-NSAIDs: inhibit synthesis of prostaglandins, reduce BF, mucus, bicarb
- gastric acid: causes ulcers by directly injuring cells of GI mucosa and activating pepsin
- pepsin: breaks down protein in gastric juice, injures cells
- smoking: delays ulcer healing and increases risk of recurrence
Three Ways Antiulcer Drugs Work - ANSWER-eradicate H. pylori (antibiotics)
- reduce gastric acidity (antisecretory agents, misoprostol)
- enhance mucosal defenses (sucralfate, misoprostol) Most common triple therapy regiment for h pylori PUD - ANSWERomeprazole 20 - 40mg bid Clarithromycin 500mg bid Amoxil 1g bid (or flagyl 500mg tid for penicillin allergy) Risk factors for PUD - ANSWERH. pylori, NSAIDs, stress, >60yo Prophylaxis for PUD - ANSWERPPI (omeprazole) Misoprostol (can cause diarrhea) ***misoprostol BBB- may cause spontaneous abortion in pregnancy Histamine 2 Receptor Antagonists - ANSWERcimetidine (Tagamet) famotidine (Pepcid) nizatidine (axid) First choice drug for treating gastric and duodenal ulcers - ANSWERH receptor antagonists
Omeprazole (Prilosec) - ANSWERproton pump inhibitor Short half life Used for short term therapy omeprazole adverse effects - ANSWER-pneumonia
- fractures (reducing acid secretion can decrease calcium absorption
- rebound acid hyper secretion
- hypomagnesemia
- c diff
- HA, vomiting, gas, and pain
- hepatic/renal impairment PPIs inhibit ____________ which can reduce the antiplatelet activity of (Clopidogrel) Plavix 20-40 % - ANSWERCYP 450 2C PPIs in elderly aluminum hydroxide - ANSWERcan cause constipation Magnesium hydroxide (Milk of Magnesia) - ANSWERAntacid. Neutralize gastric acid and inactivate pepsin. Side effects: diarrhea, renal impairment, and hypermagnesemia. Calcium Carbonate (Tums) - ANSWERCan cause acid rebound or milk-alkali syndrome; releases CO
Sodium Bicarbonate - ANSWERUsed to treat metabolic acidosis and alkalinize urine Bacteria that cause UTI - ANSWERE. coli (80%) Klebsiella Proteus Enterobacter Pseudomonas Staphylococci Enterococci Commonly used abx for UTI - ANSWERNitrofurantoin (macrobid) TMP/SMZ (bactrim) Fosfomycin ( 1 dose IV tx) Fluoroquinolones (ciprofloxacin) First gen cephalosporins (cephalexin) Phenazopyridine (Pyridium) - ANSWERa urinary tract analgesic, can cause orange or orange-red urine Use only 2 days
- caution with renal impairment Contraindicated in pyelonephritis and breast feeding
Nitrofurantoin (Macrobid) adverse effects - ANSWER- GI effects are most common, including N/V/D
- Pulmonary reactions, likely from hypersensitivity, leading to dyspnea, cough, and malaise
- Various hematologic effects, including agranulocytosis, leukopenia, thrombocytopenia, and megaloblastic anemia
- hepatotoxicity
- pregnancy—-> cleft palate, aortic problems Methenamine - ANSWERA prodrug, in acidic urine is hydrolyzed to ammonia and formaldehyde (which is lethal to bacteria). Used for: UTI Acetazolamide (Diamox) - ANSWEROral CAI. Given w/ liquid for acute angle closure. Last resort for controlling POAG. Also tx for UTI SEs: metalic taste, tingling in hands, metabolic acidosis, aplastic anemia (all oral CAIs), bone marrow suppression. Black Cohosh - ANSWERtx sx of menopause. potential hypotensive effects and hypoglycemic effects of meds. AE: liver inflammation and failure. Butterbur (Petasites hybridus) - ANSWERbrand: Petadolex
Class: Smooth Muscle Relaxant dosage forms: Petasites is a purified extract from the butterbur plant. Pyrrolizidine alkaloids, which are hepatotoxic and carcinogenic, are removed in the extraction process. As this product is not governed by the FDA, a wide variety of dosage forms and doses are available. indications: Prevention of migraines, Allergic rhinitis CoQ- 10 - ANSWER-Antioxidant cofactor for ETC; reducing BP
- Tx of CAD, angina, and used for slowing progression of Parkinsons A/E: GI disturbances Interacts with warfarin (similar to Vit k) Cranberry Juice - ANSWERMay help prevent urinary tract infections, will NOT treat Echinacea - ANSWERDerivative of the purple coneflower; prevents infection and has healing properties; used internally to support the immune system. May interfere with immunosuppressant drugs Feverfew - ANSWERmigraine prophylaxis
Caution with vasodilators, stimulants Peppermint - ANSWERUsed for headache, cold symptoms, nausea, indigestion, irritable bowel syndrome, muscle and nerve pain. Side effects include heartburn, allergic reaction. Probiotics - ANSWERlive microbes applied to or ingested into the body, intended to exert a beneficial effect Take 2 hours after abx Resveratrol - ANSWERa potent phenolic antioxidant found in red wine as well as grapes and nuts Anti platelet actions, can mimic effects of estrogen Saw Palmetto - ANSWERMay change the effects of hormones in oral contraceptive drugs, patches, or hormonal replacement therapies Taken to help tx BPH Soy - ANSWERTx hot flashes and osteoporosis St. John's wort - ANSWERUsed to tx depression Interacts with many drugs
Valerian - ANSWERpromotes sleep, reduces anxiety Harmful Supplements - ANSWERComfrey, Kava, Ma Huang Comfrey - ANSWERContains pyrrolizidine alkaloids that are associated with veno-occlusive disease Kava - ANSWERcan cause liver damage Ma Huang (Ephedra) - ANSWERCan elevate BP and stimulate the heart and CNS
