Gastrointestinal Drugs Flashcards
GI systems defense
NV side effects are called emetogenic
Reflex response to ingestion of harmful substances, sights, smells, and memories
Complications: bleeding, aspiration pneumonia, dehydration and significant weight loss, reopening f surgical wounds, severe acid/base imbalances
Nausea and vomiting
CAM therapies
- Relaxation
- Hypnosis
- Guided imagery
- Acupuncture
- Acupressure
- Music therapy
- Aromatherapy
- Ginger
- Laying down flat
- Sniffing alcohol wipes
Antiemetic that blocks dopamine receptors in the brain
Inhibits signals to vomiting center in medulla
Uses: post-op nausea, vomiting, chemotherapy, radiation sickness
Dopamine Antagonists
Ex: Chlorpromazine (Thorazine), prochlorperazine (Compazine), promethazine (Phenergan), haloperidol (Haldol)
Side effects & adverse effects of promethazine (Phenergan)
Applies to other dopamine antagonists
Side effects: Dry mouth, sedation, constipation, orthostatic hypotension, tachycardia
Adverse effects: Extrapyramidal symptoms with prolonged therapy
Antiemetic that blocks serotonin receptors in CTZ, blocks vagal nerve terminals in upper GI tract
More effective when used with dexamethasone
Uses: post-op, chemotherapy
Serotonin Antagonists
Ex: Ondansetron (Zofran), granisetron (Kytril), dolasetron (Anzemet)
Side effects & adverse effects of ondansetron (Zofran)
Side effects: Headache, dizziness, hypotension, palpitations, constipation, edema, fatigue
Misc. antiemetic blocks dopamine receptors in CTZ
Uses: post-op emesis, chemotherapy, radiation therapy
High doses can cause sedation and fatigue
Metoclopramide (Reglan)
Side effects of Metoclopramide (Reglan)
- Drowsiness, fatigue, headache, anticholinergic side effects (constipation, urinary retention, blurred vision, tachycardia)
- EPS (involuntary movements)
Nursing interventions for antiemetics
- Provide oral care after vomiting
- Avoid alcohol when taking antiemetics
- Avoid driving motor vehicles or engaging in risky behaviors
- Monitor bowel sounds
- Check vital signs
Antiemetics - Lifespan considerations for pediatrics
- Tardive dyskinesia and other EPS associated with metoclopramide
(Reglan) - Ondanestron doesn’t have CNS effects and may be indicated
Antiemetics - Lifespan considerations for pregnancy & breastfeeding
- Consult with prescriber
- Try diet and lifestyle changes first
Antiemetics - Lifespan considerations for older adults
- More likely to experience side effects (e.g. confusion)
Stimulates CTZ and acts directly on gastric mucosa
Induces vomiting
Emetics
Ex: Ipecac
Type of drug used to ease or stimulate defecation
* Soften the stool
* Increase stool volume
* Hasten fecal passage through the intestine
* Facilitate evacuation from the rectum
* Relieve or prevent constipation
Most not intended for long term use
Laxatives
Classes of laxatives
- Osmotic (saline) laxatives
- Stimulant (irritant) laxatives
- Bulk-forming laxatives
- Emollients (stool softeners)
- Combination preparations
- Lubricants
When should laxatives be avoided?
-S/sx of acute abdomen (severe abd pain, tenderness, fever, rigid abd, guarding)
-Abdominal obstruction
-Appendicitis, ulcerative colitis, diverticulitis
Do not assume its constipation. Get an Xray.
Laxatives that contain electrolyte salts
Hyperosmolar salts pull water into colon and increase water in feces to increase bulk –> stimulates peristalsis and defecation
Produces semi-formed to watery stool
Uses: Bowel prep for diagnostics or surgery
Osmotic (Saline) Laxatives
Ex:
* Sodium salts (sodium phosphate or Phospho-Soda)
* Magnesium salts (magnesium hydroxide [Milk of Magnesia],
magnesium citrate)
Side effects of magnesium hydroxide [Milk of Magnesia]
Fluid & electrolyte imbalances, cramps, NVD, flatulence
Laxatives that irritate sensory nerve endings in intestines, stimulate peristalsis
Irritates mucosa
Uses: opioid induced constipation, slow intestinal transit
Can make constipation worse if used long-term
Stimulant laxatives
Ex: Bisacodyl (Dulcolax)
Side effects & adverse effects of bisacodyl (Dulcolax)
Side effects: Dizziness, cramps, nausea, diarrhea, potassium and calcium imbalances, reddish/brown urine
Adverse effects: Overuse can decrease tone and sensation in the large intestine (usually reversible)
Laxatives that absorb water into the intestine, increase bulk, and peristalsis
Typically works in 1-3 days
Uses: short term tx, IBS, ileostomy/colostomy
Bulk forming laxatives
Ex: Psyllium (Metamucil), polycarbophil (FiberCon)
Side effects & adverse effects of psyllium (Metamucil)
Side effects: cramps, n/v/d, flatulence
Adverse effects: insufficient fluid intake causes intestinal obstruction
Bulk-Forming Laxatives: Patient Teaching
- Mix in glass of water or juice
- Stir and drink immediately
- Follow with another full glass of water
Laxatives that promotes water accumulation in the intestine and stool
Uses: Stool softener, prevent constipation, decrease straining, post-op pts
Typically starts working in 1-3 days
Emollients (Lubricants and Stool Softeners)
Ex: Docusate sodium (Colace)
Side effects of Docusate sodium (Colace)
NVD, cramping
Nursing interventions for laxatives
- Monitor fluid intake and output
- Note evidence of fluid and electrolyte imbalance resulting from watery stools
- Encourage patient to increase water intake
- Advise patient to avoid overuse of laxatives
- Warn patient that the drug is not for long-term use
- Educate patient to consume foods high in fiber
- Do not take drug within 1 hour of any other drug
Type of drug used to decrease GI motility, decrease reabsorption/secretion of fluid in bowel, decrease activity of bacteria
- Side effects: Constipation, abdominal discomfort, dizziness, dry mouth
- Adverse effects (rare): Intestinal obstruction, toxic megacolon
Antidiarrheal Drugs
Antidiarrheals: Nursing Interventions
- Monitor frequency of bowel movements
- Assess bowel sounds
- Check for evidence of dehydration
- Administer cautiously to pregnant patients, patients with glaucoma, liver disorders, or ulcerative colitis
Antidiarrheals: Patient Teaching
- Encourage patients to drink clear liquids
- Avoid fried foods or milk products
- If no relief in 2 days; if fever, abdominal pain, or distention occurs; blood or mucus appears in stool, notify prescriber
- Avoid alcohol, other CNS depressants
Antidiarrheals Life Span Considerations - pedi
- Avoid bismuth subsalicylate (contains aspirin)
- Infants and children at risk for dehydration
Antidiarrheals Life Span Considerations - older adults
- At risk for dehydration
- Affects upper GI system
- Acidic stomach contents back up (refluxes) into esophagus
- Can cause esophageal ulcers
Gastroesophageal Reflux Disease (GERD)
- Affects upper GI system
- Gastric and duodenal ulcers
- Breaks in mucosal lining
Peptic Ulcer Disease (PUD)
GERD & PUD Meds
- Histamine H2 blockers
- PPIs
- Cytoprotective drugs/Pepsin inhibitors
- Prostaglandin analogues
- Antacids
- Antibiotics
- Promotility drugs
Acid prevention
Antacids
PPIs
H2 Blockers
Mucosal Protectant
Cytoprotective drugs
General patient teaching for GERD & PUD meds
- Report reflux, heartburn, indigestion
- Report bowel movements (frequency, consistency)
- Don’t double dose
- Report GI problems (dysphagia, pain, blood in emesis/stool)
- Avoid alcohol, aspirin, NSAIDs, irritating foods
Drugs that decrease secretion of gastric acid, heal and prevent ulcers
Blocks H2 receptors in stomach –> decreases acid production
End in “tidine”
Most OTC
Histamine H2 blockers
Ex: Cimetidine (Tagamet), famotidine (Pepcid), nizatidine (Axid)
No more ranitidine (Zantac)
Side effects of famotidine (Pepcid)
headaches, agitation, dizziness, n/v, constipation/diarrhea, erectile dysfunction, skin rash, pruritis, can decrease B12 absorption
Nursing Interventions for Histamine H2 blockers
Ex: famotidine (Pepcid)
- Administer 30 minutes before meals or at bedtime to decrease food-induced acid secretion
(“-tidine” = 30 minutes before you go to dine) - Avoid smoking
- Avoid NSAIDs
- Tell patient that drug-induced impotence is reversible
- Avoid foods and liquids that cause gastric irritation
- Avoid overeating
- Decrease stress
- Avoid OTC use for more than 2 weeks, consult doctor
- Watch for confusion in older adults!
What to eat when you have an ulcer
fruits veggies, legumes, lean meats, fish & seafood, eggs, whole soy foods, fermented dairy, healthy fats, grains, green tea, herbs & spices
What to avoid when you have an ulcer
alcohol, coffee, caffeine, milk or cream, fatty meats, fried foods, heavily spiced foods, salty foods, citrus foods & juices, tomatoes, chocolate
Drugs that suppress secretion of gastric acid by inhibiting hydrogen/potassium ATPase in gastric parietal cells
Most powerful drugs for treating GERD and PUD
End in “azole”
Proton Pump Inhibitors (PPIs)
Ex: Omeprazole (Prilosec), Lansoprazole (Prevacid), Pantoprazole (Protonix), Esomeprazole (Nexium)
Side effects and adverse effects of PPIs
Side effects: diarrhea, constipation, gas, headache
Adverse effects: allergic reactions, bone fractures from porous bones, GI bleeding
Used as stress ulcer prophylaxis on Med-Surg units
PPIs
Nursing Interventions for PPIs
- Give approximately 30 minutes before meals, preferably in morning
- Assess for black, tarry stools
- Educate pts to report black/tarry stools, diarrhea, abd pain, persistent HA
PPIs Considerations for older adults
- May decrease calcium absorption (greater risk of fractures)
- Regular bone density tests due to porous bones
- May decrease vitamin B12 absorption
PPIs Considerations for pregnancy & breastfeeding
- Omeprazole- Category C
- Other PPIs- Category B
- Not recommended while breastfeeding
Neutralize acidity of stomach contents, relieve heartburn and indigestion, decrease GERD symptoms, heal ulcers
* Short-acting
Antacids
Ex: Sodium bicarbonate (Alka-Seltzer), Calcium carbonate (Tums),
Magnesium hydroxide/aluminum hydroxide (Maalox), Aluminum
hydroxide (Amphogel) –> SCAM
Side effects and adverse effects of antacids
Side effects (very rare): constipation (Al and Ca), diarrhea (Mg) = mellows GI tract), stomach cramps
Adverse effects: usually none
Reminders for antacids
Impairs absorption of other drugs
* Anti-acids = anti-mixing
* 1 hour before or after other meds
Encourage patient to drink at least 2 oz of water to ensure drug reaches stomach
- Ulceration caused by mucosal lining erosion
- Hypersecretion of HCl and Pepsin
- pH of 2-5
- Most common causes: H. pylori infection and NSAIDs
- Symptoms: n/v, feeling bloated or full, food can make pain better or worse
PUD
Meds for PUD
Antibiotics + PPI
* Amoxicillin + clarithromycin + PPI (standard triple therapy)
14 day course preferred
Other potential meds:
* Metronidazole (Flagyl): effective against sensitive strains,
side effects: n/v, can give if allergy to penicillin
* Bismuth subsalicylate (Pepto-Bismol): disrupts cell wall of H.
pylori
