Week 13 GI meds Flashcards
What are the underlying causes of GI disorders?
- dietary excess
- stress
- hiatal hernia
- esophageal reflux
- adverse drug effects
- peptic ulcer disease
What effects do drugs have on GI secretions?
- decrease GI secretory activity
- block the action of GI secretions
- Form protective covering on the GI lining to prevent erosion from GI secretions
- Replace missing GI enzymes that the GI tract or ancillary gland and organs can no longer produce
What can effect the GI secretions?
May be caused by
- caffeine, alcohol, fatty foods
What is the stomach pH suppose to be?
Stomach pH 1-4
- kill bacteria
- medications are meant to be absorbed in that pH
What is peptic ulcer disease?
- Erosions in the lining of the stomach and adjacent areas of the GI tract
What symptoms occur in peptic ulcer disease?
Gnawing, burning pain, often occurring after meals
What is often the cause of peptic ulcer disease?
Bacterial infection by Helicobacter pylori bacteria
How do you test for helibacter pylori bacteria?
- serum test for antibodies for H. pylori
- treated with antibiotics (other medications help with pain and promote healing of the ulcer)
What kinds of drugs are used in treatment of ulcers?
- Histamine-2 (H2) Antagonist
- Antacids
- Proton Pump Inhibitors
What do Histamine-2 (H2) Antagonist do?
Block the release of hydrochloric acid in response to gastrin
What do antacids do?
neutralize acids
What do proton pump inhibitors do?
suppress the secretions of hydrochloric acid into the lumen of the stomach
What is the action of Histamine-2 (H2) antagonist?
- Selectively block histamine-2 receptor sites
- This blocking leads to a reduction in gastric acid secretion and reduction in overall pepsin production
What are Histamine-2 (H2) antagonists indicated for?
- Short term treatment active duodenal ulcers, or benign gastric ulcer
- treatment of pathological hypersecretory conditions such as Zollinger-Elison syndrome
- Prophylaxis for stress induced ulcers and acute upper GI bleeding in critical patients
- Treatment of erosive gastroesophageal reflux
- Relief of symptoms of heartburn, acid indigestion, and sour stomach (OTC)
What is Cimetidine?
Histamine-2 (H2) Antagonist
What is the prototype for Histamine-2 (H2) Antagonist?
cimetidine
What are the pharmacokinetics of Histamine-2 (H3) Antagonists (Cimetidine)?
What are the contraindications and cautions of Histamine-2 (H3) Antagonists (Cimetidine)?
CONTRAINDICATIONS known allergy CAUTIONS - pregnancy and lactation - hepatic and renal dysfunciton
What are the adverse effects of Histamine 2 (H2) antagonists (Cimetidine)?
What are the drug interactions for Histamine 2 (H2) antagonist (Cimetidine)?
Warfarin, phenytoin, beta blockers, alcohol, quinidine, lidocaine, theophylline, chloroquine, benzodiazepines, nifedipine, pentoxifylline, tricyclics, procainamide, and carbamazepine
What important teaching will the nurse provide t the patient taking Histamin-2 Antagonists?
- What other meds are you taking (MAIN CONCERN- interactions with other medications)
- test first before driving because of dizziness and confusion
- treat peptic ulcer disease, GERD, heartburn, indigestion
- Adjunct therapy with GI bleeds
- Less effective in smokers
- Inform men about gynecomastia
Define gynecomastia.
enlargement of male breasts
What is the action of antacids?
- Neutralize stomach acid by direct chemical reaction
What are the indications for antacids?
- Symptomatic relief of upset stomach associated with hyperacidity, as well as hyperactivity
What are the contraindications and cautions of antacids?
CONTRAINDICATIONS - Known allergy CAUTIONS - Condition that can be exacerbated by electrolyte imbalances - GI obstruction
What are the adverse effects of antacids?
What are the drug interactions of antacids?
affect the absorption of many other PO drugs
What is the prototype for antacids?
sodium bicarbonate
Mr. Jones says he has used OTC aluminium hydroxine/magnesium hydroxide antacid (Maalox) for many yrears to treat his indigestion but it is no longer working. He asked for recommendation of another antacid.
What should the nurse say?
- could be other underlying disorders so should see your doctor (could have malignancy, ulcer, etc)
- rebound acidity
- reduces acidity reduces pain
What can aluminum and Ca cause?
constipation
What helps to neutralize the effect of aluminum and Ca?
magnesium
What is the action of Proton pump inhibitors?
Acts at specific secretory surface receptors to prevent the final step of acid production and thereby decrease the level of acid in the stomach
What are the indications for proton pump inhibitors?
- Short-term treatment of active duodenal ulcers, GERD, erosive esophagitis, and benign active gastric disease
- Long-term treatment of pathological hypersecretory conditions
What are the pharmacokinetics of Proton Pump Inhibitors?
- Acid labile, rapidly absorbed in the GI tract
- Metabolized in the liver and excreted in the urine
What do proton pump inhibitors end in?
-zole
(prototype omeprazole)
What are the contraindications and cautions of proton pump inhibitors (omeprazole)?
CONTRAINDICATION
- Allergy
CAUTION
- Pregnancy or lactation
What are the adverse effects of proton pump inhibitors (omeprazole)?
What is asthenia?
abnormal physical weakness or lack of energy
What is apathy?
lack of interest
What must the nurse think about when working with a patient on proton pump inhibitors (omeprazole)?
- Decreases Ca so worry of it leading to ostoeperosis or bone loss
- Also alters normal flora (more likely to be effected by c. difacile)
- elevate the head to help with acid (try not to eat before bed, etc)
What teaching is required for patients on proton pump inhibitors (omeprazole)?
Teaching
- know what drugs they are on (severe interactions with benzodiazepine and anticoagulants)
- how to avoid
- don’t crush or chew (have to take it whole)
- take before or with a meal for best results
What are the actions of drugs used to affect motor activity of the GI tract?
- Speed up or IMPROVE MOVEMENT of intestinal contents when movement becomes slow or sluggish (constipation)
- INCREASE TONE of the GI tract and stimulate motility throughout the system
- DECREASE MOVEMENT along the GI tract when rapid movement decreases the time for absorption of nutrients (diarrhea)
What types of meds decrease motility as a side effect?
- Ca and aluminum containing antacids
- opioids
Name 3 types of laxatives.
CHEMICAL STIMULANTS
- Chemically irritate the lining of the GI tract
BULK STIMULANTS
- Cause the fecal matter to increase in bulk
LUBRICANTS
- Help the intestinal contents move more smoothly
When would chemical stimulants be used?
- prior to diagnostic procedures or surgery
- remove ingested poisons from the lower GI; adjunct in anthelmintic
When are bulk stimulants used?
- safe short term relief of occasional constipation (mainly fibre)
- prevent straining
- to remove ingested poisons of lower GI
- adjunct to anthelmintic therapy
When are lubricants indicated for treatment?
- help with healing of ulcers
- safe short term relief of occasional constipation (mainly fibre)
- prevent straining
- to remove ingested poisons of lower GI
- adjunct to anthelmintic therapy
What are BULK STIMULANTS
- Cause the fecal matter to increase in bulk
What are CHEMICAL STIMULANTS?
- Chemically irritate the lining of the GI tract
What are LUBRICANTS
- Help the intestinal contents move more smoothly
What are some examples of chemical stimulants?
- Cascara (Generic): Reliable agent that leads to intestinal evacuation
- Senna (Senokot): Reliable drug, similar to cascara (OTC)
- Castor Oil (Neoloid): Old standby for thorough evacuation
of the intestine - Bisacodyl (Dulcolax): Very popular OTC laxative
What is the prototype of chemical stimulants?
caster oil (Neoloid)
What are some examples of BULK STIMULANTS
What is Psyllium (Metamucil) also marketed for?
Also marketing to lower cholesterol; contains fibre (psyllium); works by being high in fibre and draws in water thus increasing the bulk of the stool (which stimulates stretch receptors)
What are some types of lubricating laxatives?
Docusate (Colace)
What routes can Colace be given in?
rectal or oral
What are the actions of laxatives?
Work in 3 ways:
- Direct chemical stimulation of the GI tract
- Production of bulk or increased fluid in the lumen
- Lubrication of the intestinal bolus to promote passage through the GI tract
What are laxatives indicated for?
What are the pharmacokinetics of laxatives?
- Only minimally absorbed and exert their therapeutic effect
directly in the GI tract
What are the contraindications and cautions?
CONTRAINDICATIONS
- acute abdominal disorders (obstructions, surgery, abdominal pain)
CAUTIONS
- pregnancy and lactation
What are the adverse effect of laxatives?
- GI effects - Diarrhea, abdominal cramping, and nausea
- CNS effects – Dizziness, headache, and weakness
- CV effects – Sweating, palpitations, flushing, and fainting
- Cathartic dependency
What is cathartic dependance?
when a person requires a laxative to have a BM
What are the drug to drug interactions of laxatives?
Some interfere with the timing or process of absorption
Stressed, poor diet, and antacids used. Complains of constipation. What teaching will the nurse provide? Which laxative? What teaching?
Which laxative?
- fibre (bulk forming); few side effects, very safe, produces normal stools (take with lots of water)
What teaching?
- antacid could be contributing
- recommend exercise, fibre, stress, lots of water (at least a full glass of water; can cause a bolus of metamucil in the esophagus)
-for short term use and can cause dependance (contributes to loss of bowel tone)
What are some types of gastrointestinal stimulants?
Dexpanthenol (Ilopan)
- Increases acetylcholine levels and stimulates the
parasympathetic system
Metoclopramide (Reglan)
- Blocks dopamine receptors and makes the GI cells more
sensitive to acetylcholine
- Leads to increased GI activity and rapid movement of food through the upper GI tract
What are the actions of GI stimulants?
- Stimulate parasympathetic activity within the GI tract
- Increase GI secretions and motility
What are the indications of GI stimulants?
- Rapid movement of GI contents is desirable
What are the pharmacokinetics of GI stimulants?
What are the contraindications and cautions of GI stimulants?
Contraindications - Allergy - GI obstruction Caution -Pregnancy & lactation
What are the adverse effects of GI stimulants?
- N&V
- diarrhea
- intestinal spasms
- cramping
- decreased blood pressure and heart rate
- weakness and fatigue
What are the drug interactions of GI stimulants?
- Digoxin
- Cyclosporine
- Alcohol
What is the prototype of GI stimulants?
Metoclopramide
What routes can metoclopramide be taken?
PO, IM, IV
What is metolopramide?
GI stimulants
What is metoclopramide indicated for?
- Relief of acute or chronic diabetic gastroparesis (partial paralysis of the stomach)
- GERD patients that cannot have tradition treatment
- Prevention of postoperative or chemotherapy N&V
- Facilitates small bowel intubation
- Promotion of intestinal transit of barium
- stimulation of gastric emptying
What are antidiarrheal drugs?
stop diarrhea
What is the action of antidiarrheal drugs?
Slow the motility of the GI tract through direct action on the lining of the GI tract
What are some types of antidiarrheal drugs?
- Bismuth Subsalicylate (Pepto-Bismol)
- Loperamide (Imodium)
- Opium derivatives (Paregoric)
What is acute diarrhea?
- usually caused from a virus or something
- very old and very young may need treatment (pedialite for children)
What is chronic diarrhea?
- tumours
- crohns, collitis, IBS
- cystic collitis
Which antidiarrheal drug would be best for travellers diarrhea?
Bismuth subsalicylate (Pepto-Bismol)
When do you want to avoid the use of antidiarrheal drugs?
when you have an infectious diarrhea
What does Bismuth Subsalicylate do?
Coats the lining of the GI tract and soothes irritation stimulating local reflexes to cause excessive GI activity and diarrhea
What does Loperamide do?
Has a direct effect on the muscle layers of the GI tract; slows peristalsis and allows increased time for absorption of fluid and electrolytes
What do Opium derivatives (Paregoric) do?
Stimulate spasm within the GI tract, stop peristalsis and diarrhea
What are the actions of antidiarrheal meds?
- Slow the motility of the GI tract through direct action on the
lining of the GI tract
What are the indications for antidiarrheal drugs?
- Relief of symptoms of acute or chronic diarrhea
- Reduction of volume of discharge from ileostomies
- Prevention and treatment of traveler’s diarrhea
What are the pharmacokinetics of antidiarrheal drugs?
varies depending on drug
What are the contraindications and cautions of antidiarrheal drugs?
Contraindications - Allergy Cautions - Pregnancy and lactation - History of GI obstruction - History of acute abdominal condition - Diarrhea due to poisoning
What are the adverse effects of antidiarrheal meds?
- Constipation (most common)
- Abdominal distension
- Abdominal discomfort
- Nausea
- Dry mouth
- Toxic megacolon
- Fatigue
- Weakness
- Dizziness
What are the drug interactions with antidiarrheal meds?
depends on the drug
What is the prototype for antidiarrheal meds?
loperamide (imodium)
What routes can you take loperamide?
PO
What is the most common uncomfortable complaint of patients?
- N&V
What is vomiting?
a complex reflex reaction to various stimuli
What causes N&V?
- motion sickness
- pregnancy
- over eating
- infections
- medications (common one is opioids)
- stress
What are emetics?
- cause vomiting
What are anti emetics?
- decrease or prevent vomiting (central or locally acting)
What is dimenhydrinate?
an antihistamine antiemetic (aka Gravol)
What is important to teach people taking dimenhydrinate?
- don’t take with alcohol
- don’t drive due to drowsiness
- can cause orthostatic hypotension
Can you give gravol to children?
NO
can use pedialite
What is the action of anticholinergics/antihistamines?
Anticholinergics that act as antihistamines and block the transmission of impulses to the CTZ
When are anticholinergics/antihistamines indicated?
prevention and treatment of N&V
What are the adverse effects of anticholinergics/antihistamines?
- Drowsiness
- Confusion
- Dry mouth
- Anorexia
- Urinary frequency
