GI drugs Flashcards
diphenoxylate
related to meperidine, anti-diarrheal opiate and slows motility. Side effects include bloating and sedation
Octreotide
Somatostatin analog; Secretory diarrhea, acromegaly, VIPoma, carcinoid, cariceal bleeds
Principle of bioavailability
fraction of administered drug that reaches systemic circulation in chemically unchanged form. TO calculate, oral plasma concentrations are compared to IV concentrations. (area under oral curve x IV dose) / (Area under IV curve x oral dose).
carcinoid syndrome treatment of symptoms
Give octreotide. This will help relieve the syndrome symptoms by inhibiting secretion of a bunch of hormones. It is also used to treat VIPomas
-tidine
Cimetidine, ranitidine, famotidine; H2 blockers. Side effects of cimetidine: P450 inhibition, antiandrogen (prolactin relese), can cross BBB (confusion, diziness, headaches).
-prazole
Omeprazole lanosprazole; proton pump blocker. ZE syndrome first line
Bismuth and sucrasulfate
bind to ulcer and provides protection. For ulcer healing and traveler’s diarrhea
Misoprostol
PGE analog to increase production and secretion of gastric mucosa and decrease acid secretion. NSAID ulcer prophylaxis; PDA maintenance; induces labor; Contraindicated in women of childbearing potential
Antacids
Affect absorption of other drugs d/t changes in pH. Delay gastric emptying. Changes urinary excretion of drugs too. Aluminum hydroxide: constipation and hypophosphatemia, proximal muscle weakness, osteodystrophy, seizures. Magnesium hydroxide- diarrhea, hyporeflexia, hypotension, cardiac arrest. Calcium carbonate - hypercalcemia and rebound acid increase, can chelate and decrease other drugs effectiveness. All can cause hypokalemia
Osmotic laxatives
Magnesium hydroxide, Magnesium citrate, polyethylene glycol, lactulose(also treats hepatic encephalopathy by flora conversion into lactic and acetic acid that promote excretion of nitrogen as ammonium); used for constipation. May be used by bulimics
Infliximab
antibody to TNF-alpha, for Crohn’s and RA. Can reactivate latent TB
Sulfasalazine
combo of sulfapyridine (ABX) and 5-aminosalicylic acid (cox inhibitor) that is activated by bacterial digestion. Used for IBD. Sulfonamide toxicity, reversible oligospermia
Ondansetron
5HT-3 blocker. Central-acting antiemetic. Postoperative vomiting and for chemo adjunct. Constipation
Metoclopramide
D2 (G-inhibitory) blocker therefore increasing levels of cAMP. Increases contractility, LES tone, motility and resting tone. Doesn’t influence colon transport time. For gastroparesis of diabetics and post-surgical. Increased parkinsonian effects. Interacts with digoxin and diabetic agents. Contraindicated in parkinson patients and those w small bowell obstruction
