Download Drugs Affecting Gastroinestinal System and Nutrition

Pharmacology
Peptic Ulcer Disease
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Imbalance between mucosal defensive
factors and aggressive factors
Major defensive – mucus and bicarbonate
Major aggressive – gastric acid, H. pylori,
nonsteroidal anti-inflammatory drugs,
pepsin
Defensive factors
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Prevent the stomach and duodenum from being
harmed (self-digestion).
Mucus – continually secreted, protective effect
Bicarb – secreted from endothelial cells,
neutralized hydrogen ions
Blood flow – good blood flow helps to maintain
mucosal integrity
Prostaglandins – stimulate secretion of bicarb and
mucus and help promote blood flow, suppress
secretion of gastric acid
Aggressive factors
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Helicobacter pylori – gram negative
bacteria, can live in stomach and
duodenum
May breakdown mucus layer,
inflammatory response to presence of the
bacteria may breakdown defenses, also
produces urease – forms CO2 and
ammonia which are toxic to mucosa
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NSAIDS – inhibit the production of
prostaglandins
Decrease blood flow, decrease mucus
production and bicarb synthesis, promote
gastric acid secretion
Gastric Acid – also needs to be present for
ulcer to form – activates pepsin and injures
mucosa
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Pepsin
Smoking
Classes of drugs
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Antibiotics
Antisecretory agents
Mucosal protectants
Antisecretory agents that enhance mucosal
defenses
Antacids
Nondrug therapy
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Diet – change in eating pattern, 5-6 small
meals a day
Smoking cessation, NSAID and ASA
should be avoided whenever possible,
avoid alcohol
Antibacterial drugs
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Combinations must be used
Bismuth – disrupts cell wall of H. pylori,
pepto-bismol
Clarithromycin – inhibits protein synthesis
Amoxicillin – disrupts cell wall, good
when given with omeprazole
Tetracyclin – inhibits protein synthesis
Metronidazole – resistance,
Histamine 2-receptor antagonists
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Suppress secretion of gastric acid (activation of
H2 receptors promotes secretion of gastric acid)
Cimetidine - first available, oral, IV, IM
May take up to twelve weeks for ulcer to be
healed
Therapeutic uses – ulcers, GERD, Zollingerellison syndrome, aspiration pneumonitis,
heartburn, indigestion
Ranitidine (Zantac)
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More potent – than cimetidine
Fewer side effects
Fewer drug interactions
PO, IM, IV
Famotidine, Nizatidine
Proton Pump Inhibitors
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Suppress secretion of gastric acid
Omeprazole – prilosec – prodrug that
converts to active form in parietal cells of
stomach – inhibits enzyme that generates
gastric acid
Ulcers, GERD, Zollinger-Ellison syndrome
May contribute to development of gastric
tumors?
Other PPIs
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Lansoprazole
Rabeprazole
Pantoprazole – protonix – usually given 40
mg per day
Sucralfate
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Creates a protective barrier against acid
and pepsin
Form sticky gel that coats ulcer portion
Given every 6 hours
Very few side effects – minimal systemic
absorption
misoprostol
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Cytotec – prevention of gastric ulcers
caused by long-term NSAID therapy
Replacement for endogenous
prostaglandins
Antacids
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Peptic ulcers and GERD
Neutralize acid
Dosing – 7 times per day
Schemes of combined treatment of gastric
ulcer
De-nol + amoxycillin
De-nol + metronidazole
Omeprazole + amoxycillin + clarythromycin
De-nol + clarythromycin + metronidazole
De-nol + controlok + amoxycilin + clarythromycin
Laxatives
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Laxative effect – production of a soft
formed stool over a period of 1 or more
days
Catharsis – prompt, fluid evacuation of the
bowel, more intense
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Function of the colon – water and
electrolyte absorption
Bowel evacuation – individual
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Dietary fiber
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Constipation
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Consistency vs. frequency
Causes – diet and fluid, medications,
activity
Indications for laxative use
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Pain associated with bowel movements
To decrease amount of strain under certain
conditions
Evacuate bowel prior to procedures or
examinations
Remove poisons
To relieve constipation caused by
pregnancy or drugs
Laxative contraindications
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Inflammatory bowel diseases
Acute surgical abdomen
Chronic use and abuse
Classifications
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I – osmotic (high doses)
II – osmotic (low doses), stimulant except
castor oil – most frequently abused
III – bulk-forming, surfactant
Bulk-forming
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Identical to fiber – soften fecal mass,
increasing bulk
Temporary treatment of constipation,
preferred for patients with inflammatory
bowel diseases
May help with diarrhea
Adverse reactions
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Not absorbed – no systemic effects
Must take with sufficient water
Intestinal, esophageal obstruction
Metamucil, citrucel
Surfactant laxatives
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Bisacodyl, castor oil
Stimulate intestinal motility
Increase water and electrolytes in intestinal
lumen
Produce stool within 6-12 hours
types
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Bisacodyl – dulcolax – suppository, orally
Anthraquinones – cascara and senna
Castor oil – works in small intestine
Bisakodil
Osmotic laxatives
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Draws water into intestinal lumen
Time of action is dose-dependent
Magnesium, sodium and potassium salts
Can cause dehydration
Electrolyte imbalances
Guttalax
Miscellaneous laxatives
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Mineral oil
Lactulose
Glycerin suppository
Polyethylene glycol-electrolyte solutions
Laxative abuse
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Most common cause of constipation
Teaching
Prokinetic agents
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Reglan – suppresses emesis and increases
upper GI motility
Given for nausea related to chemotherapy
GERD
Diabetic gastroparesis
Adverse effects – diarrhea, sedation, EPS,
(dopamine antagonist)
propulsid
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GERD and nocturnal heartburn
Taken off the market
Causes potentially lethal dysrhythmias
Antiemetic drugs
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Serotonin receptor antagonists –
Ondansetron (Zofran) – most effective with
chemo-type drugs, very effective – works
well with dexamethasone
Phenothiazines
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Blocks dopamine2 receptors in the
chemoreceptor trigger zone
Side effects include EPS, anticholinergic
effects, hypotension and sedation
Prochlorperzine, phenergan,
butyrophenones
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Haloperidol and droperidol (Inapsine)
Block dopamine 2 receptors in
chemoreceptor trigger zone
Additional drugs
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Glucocorticoids
Cannaboids
Benzodiazepines
Antihistamines
Antidiarrheals
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Symptom – excessive volume and fluidity
of stools
Infection, digestion problems, bowel
disorder, inflammation
Complication and goal of
treatment
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Electrolyte imbalances and dehydration
Goal of treatment – treat underlying cause,
replace water and salts (electrolytes), relief
of pain, cramping and reducing passage of
unformed stools
Nonspecific – treat symptoms
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Opioids – slow intestinal motility, decrease
fluid in small intestine – stool goes into
large intestine with less fluid
Lomotil and imodium
Bulk-forming agents
Anticholinergics antispasmodics - atropine
Infectious diarrhea
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Infections – bacteria and virus
Salmonella, shigella, campylobacter,
clostridium
Traveler’s diarrhea – e coli
Crohn’s disease and ulcerative
colitis
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Aminosalicylates – sulfasalazine –
metabolized producing component which
reduces inflammation
Mild to moderate ulcerative colitis
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Glucocorticoids – suppress inflammation
Primarily used for an exacerbation
immunomodulators
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Azathioprine and mercaptopurine
Cyclosporine
Infliximab
methotrexate
Tocopherole acetate (Tocopheroli acetas)
Vitamin E is produced in many forms: 5 %, 10 % and 30 % oil solution in 10, 20 and 50 ml bottles; elastic
capsules with 0,1 and 0,2 ml of 50 % solution in oil; ampoules with 1 ml of 5 %, 10 % and 30 % oil
solutions.
Carsil
Legalon
Mechanism of action of legalon
Essentiale
Is produced in 5 ml ampoules and in capsules
Lipostabil
Pancreatin (Panсreatinum)
Is produced in 0,25 g and 0,5 g dragee (tablets).
Panzynorm forte
Festal, Enzistal,
Mezym-forte
No-spa, nicospan
Baralgin
Bil-berries
St. John’s wort
Pepper mint
Chamomile
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