week 5

what do stimulant laxatives do?

stimulates the bowels (increase muscle contraction)

what do bulk-forming agents do?

absorb liquid in the intestines and swell to form a soft, bulky stool

what do stool softeners / surfactants do?

increases the amount of water and fat that stool absorbs

what do osmotic laxatives do?

draw water into the stool, resulting in softer stools

what does mineral oil do to relieve constipation?

lubricates the fecal mass so it slides better against colon

what type of laxative is psyllium mucilloid (Metamucil)?

bulk-forming

what is a possible adverse effect of Metamucil?

with insufficient water, it may cause obstructions in the intestines

what is the onset of Metamucil?

12-24 hours

what type of laxative is sodium docusate?

surfactant

what is the onset of sodium docusate?

24-72 hours

what is important to know before giving a laxative?

if the cause of constipation is a blockage, then a laxative will do more harm than good D:

when does diarrhea occur?

when the colon fails to reabsorb enough water

what can occur if diarrhea is prolonged?

fluid. electroyte, and acid-base imbalances

what classes of medications treat diarrhea? (4)

• absorbents

• anticholinergics

• opiate-like probiotics

• opioids

what are two OTC medications to treat diarrhea?

• loperamide (Imodium)

• bismuth subsalicylate (Pepto-Bismol)

how do opioids treat diarrhea?

slows peristalsis

what is the onset of opioids in treating diarrhea?

45-60 mins

what class of drug is diphenoxylate (Lomotil)?

opioid

why is atropine added to diphenoxylate?

atropine is added to discourage misuse, it increases HR

what conditions contraindicate antidiarrheals? (3)

• severe dehydration / electrolyte imbalance

• liver / renal disorders

• glaucoma

what is emesis?

vomiting

what part of the brain controls vomiting?

medulla

what is emetogenic potential?

capacity of a drug to induce vomiting

what can excess vomiting lead to? (4)

• dehydration

• significant weight loss

• severe acid-base disturbances

• vascular collapse

what drugs treat moderate - severe nausea? (7)

• serotonin receptor antagonists

• antihistamines

• anticholinergics

• phenothiazines

• corticosteroids

• benzodiazepines

• cannabinoids

depends on the cause!!

how does prochloroperazine (Semetil) work to treat nausea?

inhibits signals to the vomiting center in the medulla

what are potential adverse effects of prochloroperazine? (5)

• dry mouth

• sedation

• constipation

• tachycardia

• extrapyramidal symptoms (long term use)

what class of drug is Ondansetron (Zofran)?

serotonin receptor antagonist

how do serotonin receptor antagonists treat nausea?

blocks serotonin

what cause of nausea do serotonin receptor antagonists treat?

nausea from chemo/surgery

what are potential adverse effects of serotonin receptor antagonists? (4)

• headache

• lightheadedness

• drowsiness

• constipation

what class of drug is metoclopramide (Raglan)?

prokinetic

how do prokinetic drugs treat nausea?

stimulates the muscles of the gastrointestinal tract

(when nausea is due to a sluggist GI tract)

what could blood in vomit be a sign of?

tear in esophagus

what is the role of the pancreas?

secretes insulin + digestive enzymes

how is pancreatitis treated?

pancreatic enzyme replacement

what are adverse effects of pancreatic enzyme replacement? (2)

• GI symptoms (nausea + vomiting, diarrhea)

• hyperuricosuria

what is important to ask a patient before giving pancreatic enzyme replacement medications?

if they are allergic to pork, or if they cannot eat pork due to spiritual beliefs

what is the digestive system responsible for? (3)

• breaking down food.

• absorbing nutrients.

• eliminating wastes.

peristalsis

the rhythmic contractions of the layers of smooth muscle along the alimentary canal

what are the two muscular rings in the stomach?

• esophageal (cardiac) sphincter

• pyloric sphincter

what does the esophageal (cardiac) sphincter do?

keeps food from moving back up into the esophagus

what does the pyloric sphincter do?

regulates the flow of substances leaving the stomach

what do the stomach’s chief cells do?

secrete enzymes

what do the stomach’s parietal cells do?

secrete hydrochloric acid

what protects the stomach muscosa from acid? (2)

thick mucous layer andd bicarbonate ion layer

what is the primary cause of peptic ulcer disease?

infection with Heliobacter pylori

what type of lesions are associated with cancer?

gastric ulcers

where are gastric ulcers located?

the stomach

where are duodenal ulcers located?

the small intestine

what are risk factors associated with peptic ulcer disease? (6)

• family history

• blood type O

• smoking

• caffeine

• drugs (corticosteroids, NSAIDs, platelet inhibitors)

• infection with Helicobacter pylori

what type of bacteria is Helicobacter pylori?

gram negative bacterium

what is the most common cause of peptic ulcer disease that is NOT from H. pylori infection?

NSAIDS

what drugs are used to treat peptic ulcer disease? (4)

• proton pump inhibitors

• h2 receptor antagonists

• antacids

• antibiotics

what do bismuth compounds like pepto bismol treat gastric ulcer disease?

inhibit bacterial growth + prevent H. pylori from adhering to gastric mucosa

what are the usual symptoms of duodenal ulcers? (5)

• burning upper abdominal pain

• nocturnal pain

• nausea

• vomiting

• bloody vomit / stools

when is the onset of abdominal pain for duodenal ulcers?

• occurs 1-3 hours after a meal

when is pain worse for duodenal ulcers?

• pain is worse when stomach is empty

what are symptoms of gastric ulcers? (3)

• anorexia

• weight loss

• vomiting

what is gastroesophageal reflux disease? (GERD) (2)

• caused by loosening of sphincter between esophagus and stomach

• acidic stomach contents move up into esophagus

what can esophageal relfux disease (GERD) lead to? (2)

• heartburn

• esophageal ulcers, esophagitis, or strictures

what drug classes treat GERD? (3)

• proton pump inhibitors

• h2 receptor blockers

• antacids

what is the primary goal in treating GERD?

primary goal is to reduce gastric acid secretion

what is the mechanism of action for proton pump inhibitors?

reduces acid secretion in stomach by binding irreversibly to enzyme H+ K+ - ATPase

what are adverse effects of proton pump inhibitors? (5)

• headache

• nausea

• diarrhea

• rash

• abdominal pain

what is long term use of proton pump inhibitors linked to?

increased risk of gastric cancer

how long should proton pump inhibitors be used?

4-8 weeks

what is the onset, peak, and duration of proton pump inhibitors?

onset - 1h

peak - 2h

duration - 72h

what do proton pump inhibitors treat? (2)

• peptic ulcers

• GERD

how should proton pump inhibitors be administered? (2)

• before breakfast, on an empty stomach.

• should not be crushed, divided, or chewed.

what do h2 receptor blockers treat?

peptic ulcer disease

what is the mechanism of action for h2 receptor blockers?

acts by blocking h2 receptors in stomach to decrease acid production

what are possible adverse effects of h2 receptor blockers? (2)

• reduction of WBC, RBC, and platelets.

• impotence or loss of libido in men.

when should h2 receptor blockers be administered?

after meals

what should be monitored for drugs used to treat peptic ulcers?

monitor liver and kidney function

what do antacids treat?

heartburn due to PUD or GERD

what is the mechanism of action of antacids?

neutralizes stomach acid by raising pH of stomach contents

what is a possible adverse effect of antacids?

constipation

what should be known about the administration of antacids?

administer aluminum antacids at least 2 hours before or after other drugs, because absorption could be affected

hypermagnesemia

kidneys unable to excrete excess magnesium

why are multiple antibiotics given to treat H. pylori? (2)

• increased effectiveness

• less potential for resistance

what does sucralfate (Carafate) do?

coats ulcer and protects it from further erosion

what does misoprostol (Cytotec) do?

inhibits acid and stimulates production of mucous

contraindicated with pregnancy

what does metoclopramide (Reglan) do?

causes muscles in the upper intestine to contract