GI Drug Facts

Question 1

3 Antacids and Common Side Effects of Ea

Answer 1

All cause dec bioavailability of other drugs and hypokalemia

Aluminum Hydroxide - constipation (aluminum = minimum poop), sz, hypophosphate

Calcium Carb - hypercalcemia (milk alkali syndrome), rebound inc acid and chelates other drugs

Mg Hydroxide - Diarrhea , hyporeflexive, hypotensive, cardiac arrest (makes sense b/c use Mg to stop sz)

Question 2

Sulfasalazine

Answer 2

Combo of dulfapyridine abx and 5-aminosalicylic acid (anti-inflam)

Act by bac in gut

For UC and Chrons

Question 3

Ondansteron

Answer 3

Serotonin rec antagonist for central acting anti-emetic

CHEMO

QT prolongation, constipation, serotonin syndrome

Question 4

Metoclopramide

Answer 4

D2 dopamine antagonist for gastric motility

Used for DM and post-operative gastroparesis

TARDIVE DYSKINESIA and cannot use if Parkinson’s

Question 5

Orlistat

Answer 5

Lipase STAsis - so less breakdown and absorption of dietary fats

Wt loss

Steatorrhea and dec vit ADEK

Question 6

Aprepitant

Answer 6

substance P antagonist - block NK1 receptors in brain

anti-emetic in chemo

Question 7

Laxatives (4 types)

Answer 7

1- bulk forming (psyllium and methylcellulose) - soluble fibers so drag water into lumen

2- Osmotics (Mg OH, Mg citrate, polyethylene glycol, lactulose) - osmotic load draws water into lumen

3- Stimulants (Senna) - enteric nerve stim for colonic contraction

4- Emollients (Docusate) - osmotic draw into lumen to inc water absorption of stool itself AKA stool softener

Question 8

Lactulose for Hepatic Encephalopathy

Answer 8

Degraded by gut flora into lactic acid and acetic acid which promote nitrogen excretion as NH4+

Trap weak base