Gastrointestinal Drugs Flashcards
gastric problems caused by excessive gastric acid stripipng away the protective mucus barrier
ARD-Acid-related disorders
indigestions
Dyspepsia
usually a combo of acid, pls gastrointestinal reflux (GERD)
Heartburn
inflammation/ulceration of the stomach lining by the proteolytic enzyme pepsin
PUD-peptic ulcer disease
use of aspirin and other NSAIDS, alcohol, cigarettes and caffeine, H. pylori infection, as well severe psychological and traumatic (physical) stress
other factors contributing to ARD
drugs for ARD decrease or neutralize
HCl-hydrocholoric acid in the stomach
They were the mainstay of treatment for many years and are still used a lot; they all neutralize HCl to some degree
- some have calcium too for that extra benefit
i. e. aluminum and calcium salts (Tums) and magnesium salts (Milk of Magnesia)
Oral antacids (as tablets or liquids)
Combined antacids:
To limit the tendency of single formulations to produce loose stools or constipation
Maalox (Magnesium And Aluminum hydrOXides)
Riopan (aluminum and simethicone)
Rolaids (calcium and magnesium)
effective home remedy for indigestion (but it contains high amounts of sodium and causes acid rebound within a few hours)
Baking soda
used for “gas” (it reduces surface tension of liquids to keep bubbles from forming)
Simethicone
Antihistamines which work at the histamine2 receptor (not the H1 rc like Benadryl for allergies); they were originally Rx-only and made a lot of $$ but can now be bought OTC;
I.e. Tagamet (cimetidine) intro’d in 1977 (1st superstar drug of this class), ranitidine (Zantac by Glaxo) and famotidine (Pepcid by Merck)
H2 blockers
Drugs that replaced dependence on antacids (which saw a lot of recurrence and relapse, scarring which caused obstruction, hemorrhage and perforation life-threatening events),
revolutionized treatment of ARD, peptic ulcers, complications,
and dramatically reduced the # of ulcer surgeries
H2 blockers and PPIs–proton pump inhibitors
*good idea to take antacids with H2 blockers but but don’t combine H2 blockers and PPIs–results in atrophic gastritis
Another drug method to decrease stomach acid–by shutting down the proton (H+) pump in the stomach’s parietal cells responsible for the hydrogen in HCl
- Rx Prilosec (lansoprazole) was 1st and then Nexium (esomeprazole–the ‘purple pill’)
- Prilosec was the 1st one to go OTC as the same dose as its Rx strength
PPIs–proton pump inhibitors
A gram (-) bacteria that survives well in a highly acidic environment–infects the gastric mucosa–and is very associated with the development of Peptic Ulcers;
- treated by multiple antibiotics combined with a PPI or H2 blocker or Pepto-Bismol (bismuth subsalicylate)
- treatment is often curative but the infection is hard to completely get rid of
Helicobacter Pylori
H. pylori antibody H. pylori antigen H. pylori breath test CLO test RUT-Rapid urease test
diagnostic tests for H. Pylori
Amoxicillin or clarithromycin (the macrolide Biaxin) combined with a PPI
(simplified by the recent approval of a blister pack combo of all3 drugs–‘PrevPac’)
treatment for H. Pylori
Many things ranging from infections to malabsorption to bowel irritability can cause food/secretions to move too quickly through the GI tract = ________
diarrhea
opioid drugs like codeine (anticholinergic effects to slow down the bowel); molecule structure similar to Demerol but don’t cause euphoria or really have potential for addiction
‘Lomotil’ = diphenoxylate + atropine
‘Imodium’ = loperamide
effective treatment for diahrrea
bulk agents (binding agents) which are inert, non-digestible fiber: 'Kaopectate' (kaolin and pectin)--binds excess water in the case of bacterial toxins -this type of fiber binds free water in the gut *can also be used to treat constipation (softens stools)
other antidiarrhea drugs/treatments
types of fiber that absorb excess water in the gut
Binding Agents
Indicated for heartburn treatment but is actually a very weak antacid (Mylanta and Maalox work much better)
- has antisecretory activity in the gut (decreases water excretion in stools) and bismuth absorbs toxins caused by E. coli
- a good choice to augment therapy for travelers diarrhea
Pepto-Bismol (bismuth subsalicylate)
Antibiotics along with fluid/electrolyte replacement:
I.e. TMP-SMX (Septra), ciprofloxacin (Cipro), and doxycycline (Vibramycin)
treatment for certain types of Infectious Diarrhea
Opioids like codeine & Lomotil (diphenoxylate + atropine) with anticholinergic effects;
OTC opioid-like drugs like Imodium (loperamide) with anticholinergic effects (less effective)
Binding agents to soak up excess water, inluding any dietary fiber (i.e. oatmeal), Kaopectate (kaolin/pectin) or Konsyl
Pepto-Bismol with antisecretory effects
Antibacterials
Summary of antidiarrhea drugs/treatments
Bulk agents to retain water in the stool
Stool softeners and lubricants
Irritants and stimulants to increase bowel peristalsis
Salt (saline) solutions (like Epson’s salts and hypertonic magnesium salts) to draw water into the bowel lumen and cause a “flush” effect
*these are mostly saline enemas
Laxatives/treatments for constipation
*they work by many different mechanisms
Contain cellulose fibers similar to Kaolin-Pectin fiber for diarrhea; they hold onto water and increase bulk through natural process
I.e. ‘Metamucil’ or psyllium (found in ‘Konsyl’)
Bulk agents
They don’t stimulate bowel movements but slowly create a film around the stool which allows moisture retention
- usually contain the drug docusate (like in ‘Colace’)
- best example: pure mineral oil–but should only be used temporarily to avoid significant body absorption
Stool softeners and lubricants
they work as purgatives: stimulate vigorous bowel peristalsis; shouldn’t be taken daily/too often
*high potential for abuse–especially in elderly
I.e. casor oil and sennoside compounds
Irritant/Stimulant drugs
A large group of flowering plants native to the middle east and Asia; major components of heral and folk medicine;
they are the active ingredient in Ex-lax and similar OTC irritant/stimulant axatives
the Sennas
they range from normal-tonic mixtures of NaCl (saline/Fleets enema) to hypertonic magnesium citrate solutions used as ‘bowel preps’ before colonoscopies or surgery.
*mag salts by osmosis draw water into the bowel lumen to promote emptying- “flush from above”
(I.e. Epson’s salts, Mag Citrate and other hypertonic Mg salts)
Salt solutions
pre-prepared enemas
Fleet enemas
Drugs that lessen nausea and vomiting
*some drugs do this by their side effects and we use it to our advantage
(I.e. propmethazine/Phenergen–the anticholinergic properties of 1st generation antihistamines that cross the BBB)
Antiemetics
Antipsychotics and other dopamine agonists (most commonly Compazine)
other drugs that also have an secondary antiemetic effect
Corticosteroids (dexamethasone-mainly for after chemo)
Benzodiazepines (anxiety-related)
Cannaboids (assoicated with cancer and AIDS)
all used as antiemetics in certain situations
the most recently developed antiemetics and by far the most effective (and expensive) antinausea drugs on the market
*initially only used for chemo treatment but now largely used in anesthesia and even pregnancy-related nausea
I.e. ondansetron Zofran) & dolasetron (Anzemet)
5-HT3 (Seratonin type 3) rc agonists
Most drugs in this category are given for accidental overdose or suicide attempts; usually used to empy the GI tract and/or bind and inactivate the overdosed drug
- Emetics must be given to a conscious patient and taken ASAP
(i. e. ipecac syrup)
Drugs to treat poisoning
Administration of absorbents like activated charcoal, which binds to other drugs so they cannot be absorbed into the bloodstream
*or Hemodialysis is effective if too much drug has already been absorbed
the most common treatment for drug overdose
Amphetamine-like ‘uppers’
I.e. Fen-Phen and its 1997 fiasco
Rx drugs for weight loss
An SNRI antidepressant-type drug (similar to Prozac) that suppresses appetite via serotonin (and norephinephrine) re-uptake inhibition;
-pulled from the market in 2010 because the effectiveness was too low to justify the risk of heart attack or stroke
Meridia
1st and only non-stimulant weight loss drugs approved by the FDA
lipase inhibitors
Rx drug that inhibits the enzymatic breakdown of fats (to a point), thereby decreasing caloric absorption
-around since 1999
-well tested
in
Xenical (orlistat)
Lower dose version of Xenical (orlistat) available since 2007
Alli
