NCM 106-18 Pharmacology PDF

NCM 106-18 Pharmacology Gastrointestinal Drugs Antiemetic  Vomiting Vomiting (emesis), the expulsion of gastric contents, has a multitude of causes, including motion sickness, viral and bacterial infection, food intolerance, surgery, pregnancy, pain, shock, effects of selected d...

NCM 106-18 Pharmacology Gastrointestinal Drugs Antiemetic  Vomiting Vomiting (emesis), the expulsion of gastric contents, has a multitude of causes, including motion sickness, viral and bacterial infection, food intolerance, surgery, pregnancy, pain, shock, effects of selected drugs (e.g., antineoplastics, antibiotics), radiation, and disturbances of the middle ear that affect equilibrium. Nausea, a queasy sensation, may or may not precede the expulsion The nonpharmacologic methods of decreasing nausea and vomiting include administration of weak tea, flat soda, gelatin, Gatorade, and Pedialyte (for use in children). Crackers and dry toast may be helpful. When dehydration becomes severe, intravenous (IV) fluids are needed to restore body fluid balance.  Nonprescription Antiemetics: Anhistamine Drugs (Motion Uses and Considerations Sickness) Cyclizine For prevention and treatment of motion sickness associated hydrochloride with dizziness, nausea and vomiting. Avoid concurrence alcohol use. May cause drowsiness, blurred vision, fatigue, dry mouth, nasal dryness and urinary retention. Pregnancy category B Dimenhydrinate To prevent and treat motion sickness, dizziness, nausea nad vomiting. May cause drowsiness, dizziness, headache, restlessness, dry mouth and eyes, blurred vision, urinary retention, tachycardia and hypotension. Pregnancy category B Meclizine Prevention and treatment of nausea, vomiting, vertigo and hydrochloride motion sickness. May cause drowsiness, headache, fatigue, blurred vision and dry mouth. Pregnancy category B  Prescription Antiemetics Promethazine Hydrochloride Drug class: Antiemetic Phenothiazine MOA: Blocks H1 receptor sites and inhibits CTZ Therapeutic uses: to treat and prevent motion sickness, nausea and vomiting and sedation induction Side effects: drowsiness, dizziness, confusion, anorexia, dry mouth, constipation, blurred vision, excitability, photosensitivity, hypertension, hypotension, urinary retention, fatigue, injection site reaction, incoordination, slate gray skin hyperpigmentation, erectile dysfunction Adverse reactions: Extrapyramidal syndrome, seizures. Life-threatening: Agranulocytosis, leuko[ienia, thrombocytopenia, NMS, respiratory depression  Prescription Antiemetics Drugs/ Group Uses and Considerations Scopolamin For nausea and vomiting, motion sickness and IBS. May e/ cause dizziness, drowsiness, fatigue, headcache, dry mouth, Anticholiner blured vision, urinary retention and constipation. Alternate gic eras if using for longer than 3 days, wash hands after applying and wear no more than one patch at a time. Pregnancy category C Lorazepam/ For prevention of chemo-induced nausea and vomiting and Benzodiazepin for anxiety, insomnia, procedural sedation, amnesia induction es and status epilepticus. May cause dizziness, drowsiness, amnesia, injection site reaction, suicidal ideation and dependence. Pregnacy category D Granisetron/ Serotonin For prevention and treatment of radiation and chemo- (5- HT3) receptor induced nausea nad vomiting. May cause dizziness, antagonists drowsiness, agitation, headache, fatigue, diarrhea and constipation. Pregnancy category B Metocloprami For prevention and treatment of postoperative and chemo de induced nausea and vomiting, diabetic gastroparesis and hydrochloride GERD. Avoid alcohol and CNS depressants. May cause drowsiness, fatigue, restlessness, headache, seizures, suicidal ideation and extrapyramidal symptoms. Pregnancy category B  Nursing Interventions Check vital signs. If vomiting is severe, dehydration may occur, and shocklike symptoms may be present. Monitor bowel sounds for hypoactivity or hyperactivity. Provide mouth care after vomiting. Encourage patients to maintain oral hygiene.  Patient Teaching Instruct patients to store drugs in airtight, light-resistant containers if required. Tell patients to avoid OTC preparations. Warn patients not to consume alcohol while taking antiemetics. Alcohol can intensify the sedative effect. Advise pregnant patients to avoid antiemetics during the first trimester because of possible teratogenic effects on the fetus. Antidiarrheal  Diarrhea -Diarrhea, frequent liquid stool, is a symptom of an intestinal disorder -Because intestinal fluids are rich in water, sodium, potassium, and bicarbonate, diarrhea can cause minor or severe dehydration and electrolyte imbalances. -Patients with diarrhea should avoid milk products and foods rich in fat.  Nonpharmacologic treatment for diarrhea is recommended until the underlying cause can be determined. This includes use of clear liquids and oral solutions such as Gatorade (for adults) and Pedialyte or Rehydralyte (for children) and IV electrolyte solutions. Antidiarrheal drugs are frequently used in combination with nonpharmacologic treatment.  Travelers’ Diarrhea Travelers’ diarrhea, also called acute diarrhea, is usually caused by E. coli. It ordinarily lasts less than 2 days; however, if it becomes severe, fluoroquinolone antibiotics are usually prescribed. Loperamide may be used to slow peristalsis and decrease the frequency of defecation, but it can also slow the exit of the organism from the GI tract. Travelers’ diarrhea can be reduced by drinking bottled water, washing fruit, and eating cooked vegetables. Meats should be cooked until well done.  Antidiarrheals: Opiates and Opiate-Related, Adsorbents, and Miscellaneous Agents Drugs Uses and Considerations Opiates and Opiate-related Deodorized For diarrhea. Avoid taking with alcohol and CNS opium depressant.. May cause drowsiness, dizziness, tincture confusion, weakness, hypotension, constipation and tolerance. Pregnancy category C Difenoxin For diarrhea. Avoid use in patients with narrow angle and glaucoma. May cause dizziness, drowsiness, dry mouth, atropine flushing, headache and fatigue. Pregnancy category C Loperamide For diarrhea. May cause drowsiness, dizziness, dry mouth, fatigue, hydrochlori headache and GI distress. Pregnancy category C de Antidiarrheals: Opiates and Opiate-Related, Adsorbents, and Miscellaneous Agents Drugs Uses and Considerations Absorbents Bismuth For diarrhea, dyspepsia and pyrosis. May cause subsalic dizziness, drowsiness, headache, weakness, anxiety, ylate confusion, tinnitus, tongue discoloration, hearing loss and stool discolorations. Pregnancy category C Miscellaneous Crofelemer For diarrhea in patients with HIV/AIDS. May cause flatulence, nausea, abdominal pain, arthralgia, hyperbilirubinemia and pharygitis.  Nursing Interventions Record vital signs. Report tachycardia or systolic blood pressure decreases of 10 to 15 mm Hg. Monitor respirations. Opiates and opiate-related drugs can cause CNS depression. Monitor frequency of bowel movements and bowel sounds. Notify a health care provider if intestinal hypoactivity occurs when taking a drug. Check for signs and symptoms of dehydration resulting from persistent diarrhea. Fluid replacement may be necessary. With prolonged diarrhea, check serum electrolytes  Nursing Interventions Administer antidiarrheals cautiously to pregnant patients and those with glaucoma, liver disorders, or ulcerative colitis. Recognize that a drug may need to be withheld if diarrhea continues for more than 48 hours or acute abdominal pain develops. Laxatives  Constipation Constipation, the accumulation of hard fecal material in the large intestine, is a relatively common complaint and a major problem for older adults. Insufficient water intake and poor dietary habits are contributing factors Nonpharmacologic management includes diet (high fiber), water, exercise, and routine bowel habits. - Laxatives and cathartics are used to eliminate fecal matter. Laxatives promote a soft stool, cathartics result in a soft to watery stool with some cramping, and frequently dosage determines whether a drug acts as a laxative or cathartic. There are four types of laxatives: (1) osmotics (saline), (2) stimulants (contact or irritants), (3) bulk-forming, and (4) emollients (stool softeners).  Osmotic (Saline) Laxatives -Osmotics, hyperosmolar laxatives, include salts or saline products, lactulose, and glycerin -Hyperosmolar salts pull water into the colon and increase water in the feces to increase bulk, which stimulates peristalsis -Saline products consist of sodium salt (sodium phosphate or Phospho-Soda, sodium biphosphate) or magnesium ((magnesium hydroxide [Milk of Magnesia], magnesium citrate), and a small amount is systemically absorbed  Osmotic (Saline) Laxatives *Serum electrolytes should be monitored to avoid electrolyte imbalance. - Lactulose another saline laxative that is not absorbed, draws water into the intestines to form a soft stool. It decreases the serum ammonia level and is useful in liver diseases, such as cirrhosis. Ex Glycerin  Osmotic (Saline) Laxatives Side Effects and Adverse Reactions : Adequate renal function is needed to excrete excess magnesium. Patients who have renal insufficiency should avoid - magnesium salts. Hypermagnesemia can result from continuous use of magnesium salts, causing symptoms such as drowsiness, weakness, paralysis, complete heart block, hypotension, flush, and respiratory depression. The side effects of excess lactulose use include flatulence, diarrhea, abdominal cramps, nausea, and vomiting. Patients who have diabetes mellitus should avoid lactulose because it contains glucose and fructose.  Stimulant (Contact) Laxatives -Stimulant (contact or irritant) laxatives increase peristalsis by irritating sensory nerve endings in the intestinal mucosa. -Types include those that contain bisacodyl, senna, and castor oil (purgative). -Bisacodyl is the most frequently used and abused laxative and can be purchased OTC.  Stimulant (Contact) Laxatives Bisacodyl MOA: Increases peristalsis by direct effect on smooth muscle of intestines Therapeutic Use: bowel preparation, prevention of short term treatment for constipation Side effects: dizziness, anorexia, nausea, vomiting, abdominal cramps, diarrhea, rectal burning Adverse reactions: Dependence, fluid and electrolyte imbalance Pregnancy category C  Bulk-Forming Laxatives -Bulk-forming laxatives are natural fibrous substances that promote large, soft stools by absorbing water into the intestine, increasing fecal bulk and peristalsis -Defecation usually occurs within 8 to 24 hours; however, it may take up to 3 days after drug therapy is started for the stool to be soft and well formed -Powdered bulk-forming laxatives, which sometimes come in flavored and sugar-free forms, should be mixed in a glass of water or juice, stirred, drunk immediately, and followed by a half to a full glass of water.  Bulk-Forming Laxatives * Insufficient fluid intake can cause the drug to solidify in the GI tract, which can result in intestinal obstruction -Polycarbophil, polyethylene glycol, methylcellulose, and psyllium are examples of bulk-forming laxatives. -Side-effects: If bulkforming laxatives are excessively used, nausea, vomiting, flatus, or diarrhea may occur. Abdominal cramps may occur if the drug is used in dry form.  Emollients (Stool softeners) -Emollients are lubricants and stool softeners (surface- acting or wetting drugs) used to prevent constipation. - These drugs decrease straining during defecation - Stool softeners work by lowering surface tension and promoting water accumulation in the intestine and stool. -Docusate calcium, docusate sodium, and docusate sodium with senna are examples of stool softeners.  Emollients (Stool softeners) -Side effects of mineral oil include nausea, vomiting, diarrhea, and abdominal cramping. -This laxative is not indicated for children, older adults, or patients with debilitating diseases because they might aspirate the mineral oil, resulting in lipid pneumonia. -The docusate group of drugs may cause mild cramping -Contraindications to the use of laxatives include pregnancy and inflammatory disorders of the GI tract such as appendicitis, ulcerative colitis, undiagnosed severe pain that could be caused by inflammation within the intestine (diverticulitis, appendicitis), along with spastic colon or bowel obstruction  Nursing Interventions Monitor fluid intake and output. Note signs and symptoms of fluid and electrolyte imbalances that may result from watery stools. Habitual use of laxatives can cause fluid volume deficit, electrolyte losses, and loss of the urge to defecate.  Patient Teaching Encourage patients to increase water intake (if not contraindicated), which will decrease hard, dry stools. Advise patients to avoid overuse of laxatives, which can lead to fluid and electrolyte imbalances and drug dependence. Suggest exercise to help increase peristalsis. Teach patients not to chew tablets but to swallow them whole. Direct patients to store suppositories at less than 86°F (30°C).  Patient Teaching Counsel patients to take drugs only with water to increase absorption. Educate patients not to take the drug within 1 hour of any other drug. Warn patients that the drug is not for long-term use; bowel tone may be lost. Encourage patients to time administration of the drug so as not to interfere with activities or sleep.