GI Drugs Flashcards
Chapter 56
Gastrointestinal System Review
Acid production in the stomach is stimulated by which factors?
Protein in the stomach Calcium products in the stomach Alcohol in the stomach low levels of acid in the stomach H2 stimulation
What are the 3 accessory organs of the GI system?
Pancreas
Liver
Gallbladder
What is the “nervous system” of the GI tract called?
Enteric nervous system
What are the 4 major activities of the GI system? ** KNOW THIS
SADM
Secretion: Of enzymes, acid, bicarbonate, and mucus
Absorption: Of water and almost all of the essential nutrients needed by the body
Digestion: Of food into usable and absorbable component
Motility: Movement of food and secretions through the system
What is secreted?
BAE
Bicarbonate mucus
Acid
Enzymes
and Mucus facilitates the digestion and absorption of nutrients.
What is absorbed?
Water and almost all of the essential nutrients needed by the body
GI system is controlled by what?
Nerve plexus
What does the nerve plexus do?
Maintains basic electrical rhythm.
Responds to local stimuli to increase or decrease activity
The nurse is aware that the types of secretions that the GI tract produces are?
HINT:8
Saliva Mucus Acid and digestive enzymes (Gastrin) Secretin Sodium bicarbonate Pancreatic enzymes, other lipases, and amylases Bile Endocrine hormones
Digestion is the process of?
Breaking food into usable, absorbable nutrients
Absorption is
The active process of removing water, nutrients, and other elements from the GI tract
What happens once water, nutrients, etc…are removed from GI tract?
They are delivered to the bloodstream for use in the body
What is GI Motility?
GI tract depends on an inherent motility to keep things moving through the system.
In the esophagus the basic movement is
Peristalsis
How many layers does the stomach use to produce a churning action?
3 layers
Mucosa- forms folds called rugae
Submucosa-controls secretions and smooth muscle contractions
Muscularis externa- protects 2 other layers
Basic movement in the esophagus
Peristalsis
Small intestine use a process of
Segmentation
Large intestine uses a process of
Mass movement
When the renal capsule becomes irritated the gastrointestinal tract shuts down?
Rationale: Renointestinal Reflex: Irritation or swelling of the renal capsule causes a cessation of movement in the GI tract, again to prevent further irritation to the capsule.
What are some underlying causes of GI disorders?
Dietary Excess Stress Hiatal Hernia Esophageal Reflux Adverse Drug Effects Peptic Ulcer Disease
What is ondansetron (Zofran) prescribed for?
To help relieve nausea symptoms
A series of local reflexes within the GI tract helps maintaine homeostasis within the system. A change of any of these reflexes may result in disruption of
homeostasis- constipation (underactivity) or diarrhea (overactivity)
Swallowing is controlled by the?
Medulla
Vomiting is controlled by the CTZ
in the medulla or by the emetic zone in immature or injured brains.
Ch 57 Drugs affecting GI Secretions
Effect of Drugs on GI Secretions
Decrease GI secretory activity
Block the action of GI secretions (GERD)
Form protective coverings on the GI lining to prevent erosion from GI secretions (PUD)
Replace missing GI enzymes that the GI tract or ancillary glands and organs can no longer produce
Which are the 2 main secretion “culprits”
GERD and PUD
KNOW THIS - GERD
When we swallow food, it travels down the esophagus through the
esophageal sphincter.
This blocks the food from coming back up.
When it doesn’t, food/gastric juices can go back up the esophagus.
This can cause erosions on the esophagus and also nausea
Bad news if this comes back up and go up the trachea
However if esophageal sphincter does not properly close then the acid goes up the esophagus causing GERD
Peptic Ulcer Disease
Define
Symptoms
Cause
Definition
Ulcers are sores or abrasions on the lining
Erosions in the lining of the stomach and adjacent areas of the GI tract
Symptoms
Gnawing, burning pain, often occurring after meals, stomach ache
Cause
Bacterial infection caused by Helicobacter pylori bacteria (h. Pylori and Stress!!)
think stress ulcer
5 Drugs Used to Treat GERD and PUD
1. H2 antagonist
What is the prototype?
and adverse effects
Histamine-2 (H2) Antagonists:
BLOCK the release of hydrochloric acid in response to gastrin (blocks the receptor sites)
prototype? cimetidine
Route: Oral
IM, IV rapid onset
Adverse effects: dizziness, confusion, headache, somnolence, cardiac arrhythmias, cardiac arrest, diarrhea, impotence, gynecomastia, rash
Drugs that treat GERD and PUD
- Antacids
What is the prototype?
group of inorganic chemicals that NEUTRALIZE stomach acid
prototype? sodium bicarbonate
5 Drugs Used to Treat GERD and PUD
3.Proton Pump Inhibitors:
What is the prototype?
drug that blocks the H+, K+, -ATPase enzyme system on the secretory surface of the gastric parietal cells, thus interfering with the final step of acid production and lowering acid levels in the stomach
(Suppress the secretion of hydrochloric acid into the lumen of the stomach)
Prototype: omeprazole
5 Drugs Used to Treat GERD and PUD
4. GI Protectants:
What is the prototype?
Coat any injured area in the stomach to prevent further injury from acid
Prototype: sucralfate
Think: Pepto Bismol
5 Drugs Used to Treat GERD and PUD
- Prostaglandins:
HINT: can also induce labor
Inhibit the secretion of gastrin and increase the secretion of the mucous lining of the stomach, providing a buffer gastrin digestive hormone secreted by the GI tract
Prototype: misoprostol (Cytotec)
What are the 4 Histamine 2 antagonists?
HINT: H2 antagonists
How do these work?
the "tidine"s, most of these are all OTC cimetidine (Tagamet HB) NO peds! famotidine (Zantac) may cause cancer? nizatidine (pepcid) _ NO peds! ranitidine (Axid)
Selectively block the secretion sites and takes acid secretion down.
This blocking leads to a reduction in gastric acid secretion and reduction in overall pepsin production
Histamine-2 (H2) Antagonists
Indications/TX
HINT: ZE syndrome
Short-term treatment of duodenal ulcer or benign gastric ulcer (acute bleeding in critical patients)
GERD, prophylaxis of stress ulcers,
relief of symptoms of heartburn, acid digestion, sour stomach
Treatment of pathological hypersecretory conditions such as Zollinger–Ellison syndrome
give one of the “tidines” to treat this condition
Histamine-2 (H2) Antagonists
Think Pepcid AC
Pharmacokinetics and contraindications
Pharmacokinetics
Readily absorbed after oral administration
Metabolized in the liver and excreted in urine
Contraindications
Known allergy
Histamine-2 (H2) Antagonists
Caution
Adverse Effects
Caution
Pregnancy or lactation
Hepatic or renal dysfunction
(Liver/Kidney)
Adverse Effects
GI effects (diarrhea/constipation)
CNS effects NONE
Cardiac arrhythmias and hypotension (RARE)
Drug to drug interactions
Warfarin phenytoin beta blockers Alcohol Quinidine Lidocaine theophyllineChloroquine
Benzodiazepines
Nifedipine
Pentoxifylline
Tricyclics
Procainamide
carbamazepine
Name the antacids aluminum salts (alternaGEL) calcium salts (oystercal, Tums) Magnesium salts (milk of magnesia) Sodium bicarbonate (Bell-ans)
SCAM
aluminum salts (alternaGEL) calcium salts (oystercal, Tums) Magnesium salts (milk of magnesia) Sodium bicarbonate (Bell-ans)
Nursing ConsiderationsHistamine-2 (H2) Antagonists
Assess:
History and Physical Exam and known allergy
Impaired renal or hepatic function
Skin, pregnancy and lactation
Neurological status, including orientation and affect
cardiopulmonary status, including pulse, blood pressure, abdomen and liver, and appropriate lab values
Question:
Drugs act in several ways on the secretions of the GI tract. Which action affects the GI secretions least?
Replaces secretions
Rationale: The effects of drugs on GI secretions: decrease GI secretory activity; block the action of GI secretions; form protective coverings on the GI lining to prevent erosion from GI secretions; replace missing GI enzymes that the GI tract or ancillary glands and organs can no longer produce.
Cimitidine is used how in a hospital setting?
HINT: H2 antagonist
used in a hospital (ICU) in IV form, especially on intubated patients, it works rapidly, used to turn down the volume of the acid for a patient that is immobile so that they don’t aspirate on their own GI acid
Antacids(protect the stomach from its own acid)
CAN DAMAGE ESOPHAGEAL LINING
Antacids
S, C, A, M
Sodium bicarbonate (Bell-ans) Calcium carbonate (Oystercal, Tums) Aluminum salts (Amphojel) Magnesium salts (Milk of Magnesia) all OTC
Antacids
Actions
Indications
Actions
Immediately neutralizes the stomach acid
Fast (immediate) relief
Indications
Symptomatic relief of upset stomach associated with hyperacidity, as well as hyperactivity
Antacids
Contraindications
Caution
Contraindications Allergy Caution Any condition that can be exacerbated by electrolyte imbalance GI obstruction (absent bowel sounds)
Antacids
Adverse Effects
(sometimes have to switch patient to a PPI instead)
Adverse Effects Constipation – Aluminum and calcium Diarrhea – magnesium Upset stomach and liquid BM – magnesium Hypercalcemia - calcium Rebound acidity Alkalosis Hypophosphatemia
Antacids
Drug-Drug Interactions
Affect the absorption of many other drugs
NO! mixing with other drugs
Take at least 1 hour before.
Messing with efficacy of other meds
Nursing Considerations for Antacids
Assess:
Do not take with other meds
It does not last long
History and Physical Exam and known allergy
Renal dysfunction, electrolyte disturbances, and current status of pregnancy or lactation
Abdomen and BS, mucus membranes and appropriate lab values
Nursing Considerations for Antacids
1 hour before or after other meds
Assess for bowel sounds, must be present!
Not for heart failure
Antacids
Prototype: Sodium Bicarbonate
Oral - rapid
IV immediate
Adverse effects: gastric rupture, systemic alkalosis, (headache, nausea, irritability, weakness, tetany, confusion), hypokalemia, gastric acid rebound
- Proton Pump Inhibitors(Suppress the secretion of hydrochloric acid into the lumen of the stomach
“PRAZOLE” drugs
Lots of “P”
“PRAZOLE” drugs Omeprazole (Prilosec) Esomeprazole (Nexium) Pantoprazole (Protonix) PROTONIX IS THE MOST GIVEN IN HOSPITALS (CAN BE GIVEN IV) Lansoprazole (Prevacid) Dexlansoprazole (Kapidex) Rabeprazole (Aciphex)
- Proton Pump Inhibitors
Indications
Indications Heartburn GERD Ulcer prophylaxis Short-term treatment of active duodenal ulcers Erosive esophagitis benign active gastric disease Long-term treatment of pathological hypersecretory conditions
Mainly used for heartburn, GERD, and ulcer prophylaxis in the hospital due to stress. Usually, most patients in the hospital are placed on PPI.
Pharmacokinetics
Pharmacokinetics
Acid labile, rapidly absorbed in the GI tract
Metabolized in the liver and excreted in the urine
Proton Pump Inhibitors
Contraindications
Caution
Contraindications
Allergy
Caution
Pregnancy or lactation
- Proton Pump Inhibitors
RARE ADVERSE EFFECTS
REVIEW AND LEARN
Adverse Effects
CNS effects: Dizziness, headache, asthenia, vertigo, insomnia, apathy
GI Effects: Diarrhea, abdominal pain, and tongue atrophy
Upper respiratory tract symptoms: Cough, stuff nose, hoarseness, and epistaxis
Other: Rash, alopecia, pruritis, dry skin, back pain, and fever
