Pharmacology Drug Cards.

RN Pharmacology Gastrointestinal

Drugs

Adeline Samba DNP, MSN ed, RN

Chapter 45: Antiemetic and Antinausea Drugs

Drug Class Drug Action/Uses Adverse effect Nursing implications

Anticholinergic drugs scopolamine Block transmission of nauseating stimuli to CTZ Drowsiness, dry mouth: blurred vision caused by pupillary dilation; tachycardia constipation.

These drugs should not be used by patients with glaucoma.

Antihistamine drugs (H1 receptor blockers)

dimenhydrinate (Dramamine) diphenhydramine (Benadryl) meclizine (Antivert)

Inhibit ACh by binding to H1 receptors Drowsiness dry mouth: blurred vision caused by pupillary dilation; and constipation.

These drugs should not be used by patients with glaucoma.

Antidopaminergic drugs

prochlorperazine (Compazine) promethazine (Phenergan)

Block dopamine receptors in the CTZ restlessness, weakness, dystonic reactions, agitation dry mouth, urinary retention, and constipation

See speaker notes

Neurokinin receptor antagonists

Aprepitant Fosaprepitant

Inhibit substance P/neurokinin 1 receptors in the brain stem

dizziness, fatigue, headache, weakness, hiccups, cough, abdominal pain, dyspepsia, and diarrhea

See speaker notes

Prokinetic drugs Metoclopramide (Reglan)

Block dopamine receptors in the CTZ Also stimulate peristalsis in GI tract, enhancing emptying of stomach contents  

drowsiness, dizziness, dysgeusia, fatigue, restlessness, headache, nausea, and vomiting.

See speaker notes

Serotonin blockers dolasetron (Anzemet) granisetron (Kytril) ondansetron (Zofran) palonosetron (Aloxi)

Block serotonin receptors in the GI tract, CTZ, and VC

dizziness, drowsiness, agitation, headache, fatigue, malaise, diarrhea, hypotension, urinary retention, fever, and constipation.

See speaker notes

Tetrahydrocannabinoi ds

Dronabinol (Marinol)

Inhibitory effects on reticular formation, thalamus, cerebral cortex

drowsiness, dizziness, impaired cognition, euphoria, dysphoria, paranoia, emotional lability, nausea, vomiting, and abdominal pain

See speaker notes

Chapter 45: Antidiarrheals

Drug class Drug Action/use Adverse effect Nursing Implications

Adsorbents bismuth subsalicylate (Pepto-Bismol), colestipol and cholestyramine

Coat the walls of the gastrointestinal (GI) tract Bind to the causative bacteria or toxin, which is then eliminated through the stool

Increased bleeding time dizziness, drowsiness, headache, tongue and stool discoloration, and anxiety

 

Antimotility drugs Opiates opium tincture, codeine loperamide, diphenoxylate

Decrease bowel motility and reduce pain by relief of rectal spasms! Decrease transit time through the bowel, allowing more time for water and electrolytes to be absorbed

Drowsiness, dizziness, lethargy Nausea, vomiting, constipation. Respiratory depression Hypotension Urinary retention Flushing

Check for signs and symptoms of dehydration resulting from persistent diarrhea.   Recognize that a drug may need to be withheld if diarrhea continues for more than 48 hours or acute abdominal pain develops

Laxatives

Drug class Drug Action/use Adverse eff ect Nursing implication

Bulk forming psyllium (Metamucil) methylcellulose (Citrucel)

Absorb water to increase bulk Impaction Fluid overload Electrolyte imbalances Esophageal blockage   Instruct patients to mix the drug in 8 to 10 oz of water and to stir and drink.  

All laxatives can cause electrolyte imbalances! Advise patients to avoid overuse of laxatives, which can lead to fluid and electrolyte. Advise patients to avoid inhaling psyllium dust; it may cause watery eyes, runny nose, and wheezing.

Emollient (stool softeners, lubricant laxatives)

docusate salts mineral oil

Promote more water and fat in the stools. Lubricate the fecal material and intestinal walls

nausea, vomiting, diarrhea, and abdominal cramps. Prolonged use may cause fluid and electrolyte

 

Hyperosmotic Polyethylene glycol (PEG) Sorbitol, glycerin Lactulose

Increase fecal water content. Results in bowel distention, increased peristalsis, and evacuation

Electrolyte imbalances Rectal irritation flatulence, diarrhea, abdominal cramps, nausea, and vomiting.

Lactulose (also used to reduce elevated serum ammonia levels for hepatic encephalopathy)

Saline Magnesium hydroxide (Milk of Magnesia) Magnesium citrate (Citroma)  

Increase osmotic pressure within the intestinal tract, causing more water to enter the intestines

Cramping, Electrolyte imbalances Diarrhea, Increased thirst

Magnesium toxicity (with renal insufficiency) Magnesium citrate for bowel preparation

Stimulant senna (Senokot) bisacodyl (Dulcolax)

Increases peristalsis via intestinal nerve stimulation

Nutrient malabsorption Skin rashes, Gastric irritation dizziness, nausea, abdominal cramps, weakness, and reddish-brown urine Electrolyte imbalances Rectal irritation

 

Chapter 46: Antiulcer Drugs

Drug class Drug Action/uses Adverse effect Nursing implication Antacids Aluminum hydroxide

  neutralize acid secretions Anorexia, constipation,

weakness, impaired cognition    

 

Antacids Magnesium hydroxide  

neutralize acid secretions Diarrhea hypercalcemia, hypermagnesemia, hypophosphatemia, anorexia, nausea, vomiting, constipation, diarrhea, and weakness

Warn that taking an unlimited amount of the antacid is contraindicated.

Antacids calcium carbonate    

neutralize acid secretions kidney stones, hypercalcemia, hypophosphatemia, nausea, vomiting, constipation, flatulence, headache, and metabolic alkalosis

Monitor for signs of kidney stones

Antacids Sodium Bicarbonate neutralize acid secretions   flatulence, gastric distension, peripheral edema, hypernatremia, metabolic alkalosis, and tremor.

Sodium content may cause problems in patients with heart failure (HF), hypertension, or renal insufficiency.

Antiflatulents Simethicone  

Help excrete gas    

Chapter 46: Antiulcer Drugs

H2 receptor blocker cimetidine (Tagamet)      

Competitively block the H2 receptor of acid-producing parietal cells Decrease acid production

dizziness, diarrhea, drowsiness, agitation, gynecomastia, and erectile dysfunction

 

H2 receptor blocker Famotidine Same as above Headache, dizziness, drowsiness, confusion, insomnia, N/V/D, constipation, depression, rash, fatigue, arthralgia, muscle gynecomastia, cramps, weakness, ED.

 

Proton Pump Inhibitors Esomeprazole (Nexium) Omeprazole (Prilosec) Pantoprazole (Protonix)    

Prevents the movement of hydrogen ions from the parietal cell into the stomach.

PPIs are generally well tolerated. GI tract infections Osteoporosis headache, dizziness, diarrhea or constipation, abdominal pain, vitamin B12 deficiency, and hypomagnesemia

 

Miscellaneous Sucralfate (Carafate) forming a protective barrier in stomach lining and prevent erosion

Dizziness, drowsiness, headache, nausea, vomiting, flatulence, constipation, dry mouth, rash, pruritus

 

Miscellaneous Misoprostol (Cytotec) Protect gastric mucosa from injury

headache, nausea, vomiting, flatulence, diarrhea, abdominal pain, chills, shivering, and hyperthermia

Used for prevention of NSAID- induced gastric ulcers

Reference

• Yeager, L.M.K.D.M.B.W. J. ([Insert Year of Publication]). Pharmacology (11th ed.). Elsevier Health Sciences (US).  https://pageburstls.elsevier.com/books/ 9780323793179