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GI/Renal Drugs
For Pharmacology NURS 422
Term | Definition |
---|---|
Classes of GI Drugs | Anti-emetics (Prevents vomiting) Anti- diarrheals (Treats diarrhea) Laxatives (Treats constipation) |
What is emesis? | Vomit. Direct Stimuli includes signals from: The cerebral cortex (anticipation or fear) Sensory Organs (Seeing gross stuff, smelly odors, pain) Vestibular apparatus of ear (Motion sickness) Indirect stimuli activate the chemoreceptor trigger zone |
Three types of emesis | Anticipatory (before drugs) Acute (happens in a few minutes or hours) Delayed (A day or more after drugs) |
Anti-emetics | Drugs that prevent vomiting |
Main classes of anti-emetics used A LOT in nursing practice | Serotonin Receptor Antagonists Dopamine Antagonists |
Ondansetron (Zofran) | ANTI-EMETIC: SEROTONIN RECEPTOR ANTAONIST First approved to give BEFORE chemotherapy. Prevents nausea and vomiting coming from anesthesia and radiotherapy. Given PO, IV, SL (Under tongue) |
Ondansetron MOA | Binds to Type 3 Serotonin receptors (5HT3) on afferent vagal nerve. Serotonin can't bind to their receptors, thus, cannot stimulate the act of vomiting. |
Ondansetron Adverse Effects | Headache, Dizziness, Diarrhea Prolonged QT Interval, which can lead to dysrhythmias (Can be fatal) and increases the risk of TdP Torsades de Pointes (TdP) - Tachycardia occurring in the heart ventricles. |
Metoclopramide (Reglan) | ANTI-EMETIC: DOPAMINE ANTAGONIST Given before chemotherapy and after surgery. PO/IV/Suppository |
Metoclopramide MOA | Binds to dopamine and serotonin receptors on the CTZ, preventing dopamine and serotonin from binding. Increases upper GI motility (gets food out of stomach fast) and suppresses emesis. |
Metoclopramide Adverse Effects | HIGH-DOSE THERAPY: Sedation and diarrhea are common. LONG-TERM HIGH-DOSE THERAPY: Can cause irreversible tardive dyskinesia (TD) |
Metoclopramide Nursing Considerations | Drug should be taken 30 mins before each meal and before bedtime. This medication is used to TREAT hiccups. It does not CAUSE hiccups. |
Tardive Dyskinesia (TD) | A drug induced movement disorder that continues a month after discontinuation of said drug. Symptoms include ticks, akathisia (unable to stay still), lip smacking, cheek puffing, excessive eye blinking, rolling of the tongue, and jaw clenching. |
Anti-diarrheals | Treats Diarrhea |
Two major groups of antidiarrheals | Specific Antidiarrheal Agents (Treats the CAUSE) Nonspecific Antidiarrheal Agents (RELIEVES symptoms) |
Diphenoxylate/Atropine (Lomotil) Loperamide HCL (Imodium) | OPIODS - NONSPECIFIC ANTIDIARRHEAL AGENT *LOW abuse potential *DO NOT give to patients w/infectious diarrhea. Clear infection BEFORE administration |
Atropine & Loperamide MOA | Activates opioid receptors in GI Tract Reduces intestinal mobility -> Slows intestinal transit Allows more fluid to be absorbed |
Atropine & Loperamide Side Effects | Drowsiness, Euphoria |
Laxatives | Treat Constipation (Pharmacologic Approach) *HIGH level of abuse |
What is constipation? | Delayed transport through colon, thus causing excessive fluid absorption and hardened stool. Can be idiopathic, from low fiber diet, IBS (Irritable Bowl Syndrome), Opioids |
Non-pharmacologic approach to treating constipation | Increasing dietary fiber (Veggies, fruits, nuts) *HYDRATION (when body is hydrated, less water is drawn from colon) |
Laxative Classification: TIME | Group 1: Acts in 2-6 hours - Watery Stool (Used before diagnostic procedures/surgery) Group 2: Acts in 6-12 hours - Semifluid Stool Group 3: Acts in 1-3 days - Soft, formed Stool |
Laxative Classification: MOA | Bulk-forming Surfactant Stimulant Osmotic Other |
Psyllium (Metamucil) | BULK-FORMING LAXATIVE | GROUP 3 Used for Diverticulosis & IBD |
Psyllium MOA | Swells with water to form gel-like material, softening and increases fecal mass |
Psyllium Adverse Effects | Esophageal Obstruction Intestinal Obstruction (Bloating, Pain, Constipation) |
Psyllium Nursing Considerations | MUST be taken with a large class of water |
Docusate Sodium (Colace) | SURFACTANT LAXATIVE | GROUP 3 Is known as a 'stool softener' *Popular medication/HIGH abuse potential |
Docusate Sodium MOA | Lowers surface tension by allowing water to penetrate into feces. Stops fluid absorption, stimulates water secretion and electrolytes into intestinal lumen |
Docusate Sodium Adverse Effects | Laxative Dependence (BIG), Dehydration, Electrolyte Abnormalities |
Docusate Sodium Nursing Considerations | MUST be taken with a large glass of water |
Bisacodyl (Dulcolax) Senna (Senakot) Castor Oil | STIMULATE LAXATIVES | GROUP 2 *Widely used and abused Used for opioid-induced constipation & constipation from slow intestinal transit |
Bisacodyl | Senna | Castor Oil MOA | Stimulates intestinal mobility Increase water and electrolyte secretion in intestinal lumen/decreases absorption |
Milk of Magnesia Polyethylene Glycol (Miralax) Lactulose | OSMOTIC LAXATIVES | GROUP 1 Used for constipation (in low doses), preparation for diagnostic procedure/surgery (i.e: coloscopy), purging ingested poisons, and evaluation of parasites |
Milk of Magnesia | Polyethylene Glycol | Lactulose MOA | Draws water into intestinal lumen Softens/Increases fecal mass, stretches intestinal wall, and simulates peristalsis |
Milk of Magnesia | Polyethylene Glycol | Lactulose Adverse Effects | Dehydration Acute Renal Failure/Magnesium Toxicity Sodium Retention |
PEG-ELS Important Note | Polyethylene Glycol Electrolyte Lavage Solution provide an isosmotic solution, thus does not cause dehydration or electrolyte imbalance |
Mineral Oil Glycerin Suppository | OTHER LAXATIVES |
Mineral Oil | For poorly absorbed hydrocarbons/produces lubrication Useful when administered by enema to treat fecal impaction |
Glycerin Suppository | Osmotic Agent - Softens/lubricates impacted feces in 30 mins - May also stimulate rectal contraction - Useful for reestablishing normal bowel function after termination of chronic laxative use |
Laxative Use Contraindications | - Abdominal pain, nausea, cramps, other symptoms of appendicitis, regional enteritis, diverticulitis, or ulcerative colitis - Acute surgical abdomen - Fecal impaction/Bowel obstruction - Habitual Use |
Why use laxative with caution in pregnancy and lactation? | Laxatives can stimulate contractions in pregnancy |
What drugs are used to treat Irritable Bowel Disease (IBD)? | Immunosuppressants Immunomodulators Antibiotics Glucocorticoids |
What is Irritable Bowel Disease (IBD)? | An exaggerated immune response directed against normal bowel flora |
Peptic Ulcer Disease (PUD) | Erosion of gut wall (stomach/duodenum) ranging from minor to severe. Caused by imbalance between mucosal and aggressive factors |
Pathogenesis of Peptic Ulcers | Helicobacter Pylori (H.Pylori) NSAIDS Gastric Acid Pepsin Smoking |
Therapeutic Approaches for PUD | Non-pharmacologic (Changing diet, avoid smoking/alcohol) Pharmacologic (Eradicate H.Pylori, limiting NSAIDS, addressing increased acidity of stomach) |
Classes of Anti-Ulcer Drugs | Antibiotics (for H.Pylori) Anti-secretory Agents Antacids Mucosal Protectants |
Anti-Secretory Agents | Drugs that reduce gastric acidity |
Classes of Anti-secretory Agents | Histamine Receptor Antagonist (H2 Blockers) Proton Pump Inhibitor |
Cimetidine (Tagamet) Famotidine (Pepcid) | ANTI-SECRETORY: HISTIMINE RECEPTOR ANTAGONISTS Given IV, PO (30 mins before meals for best benefit) |
Cimetidine | Famotidine MOA | Promotes healing by suppressing gastric acid secretion |
Cimetidine | Famotidine Side Effects | Headache, Somnolence Gynecomastia in men (Anti-androgenic), reduce libido |
Cimetidine | Famotidine Drug Interactions | Warfarin, phenytoin (Anticonvulsant), theophylline (Bronchodilator), lidocaine (Antiarrhythmic & anesthetic) |
Omeprazole (Prilosec), Esomeprazole (Nexium), Lansoprazole (Prevacid) | ANTI-SECETORY: PROTON PUMP INHIBITOR Used to treat GERD (Long term use) Given IV, PO |
Omeprazole | Esomeprazole | Lansoprazole MOA | Stops the H+/K+ APTase proton pump |
Omeprazole | Esomeprazole | Lansoprazole Side Effects | Headache, pneumonia, fractures (osteoporosis), C.Diff |
Omeprazole | Esomeprazole | Lansoprazole Drug Interactions | HIV Medication (REDUCES absorption), antifungals, Clopidogrel (Plavix) Do NOT combine any of these drugs with a PPI |
Omeprazole | Esomeprazole | Lansoprazole Contraindication | HIV Patients (DO NOT give) |
Magnesium Compound (MOM), Calcium Compound (Tums), Sodium Compound, Aluminum Compound | ANTI-ULCER: ANTACIDS |
Magnesium Compound | Calcium Compound | Sodium Compound | Aluminum Compound MOA | React with gastric acid to produce neutral salts or salts with low acidity Reduces gut wall destruction by neutralizing acid Enhances mucosal protection by stimulating production of prostaglandins |
Magnesium Compound | Calcium Compound | Sodium Compound | Aluminum Compound Adverse Effects | Constipation, Diarrhea |
Magnesium Compound | Calcium Compound | Sodium Compound | Aluminum Compound Drug Interactions | Cimetidine, Ranitidine (H2 Blockers) |
Misoprostol (Cytotec), Sucralfate (Carafate) | ANTI-ULCER: MUCOSAL PROTECTANTS |
Misoprostol | Sucralfate MOA | Creates a physical barrier that protects the GI tract |
Misoprostol | Sucralfate Side Effects | Misoprostol: Category X Drug (INDUCES uterine contractions) Sucralfate: Interference with antacids |
Hepatitis C (LIVER) | Liver infection caused by the Hep. C virus. Transmission occurs through blood, sex, IVDU (IV Drug use) |
Hep. C Standard of Care (Medications) | Interferon Alfa Ribavirin Direct Acting Antiviral Drugs |
Interferon Alfa | HEP. C TREATMENT: ANTIVIRAL Sub Q, IM Injections |
Interferon Alfa MOA | Blocks viral entry and replication in liver |
Interferon Alfa Side Effects | Flu-like syndrome, neuropsychiatric disorder (depression) |
Ribavirin (Rebetol) | HEP. C TREATMENT: ANTIVIRAL Oral Dosing |
Ribavirin MOA | Unclear. Needs to be combined with Interferon-Alfa to be effective |
Ribavirin Adverse Effects | Hemolytic Anemia (DO NOT give to patients with heart disease) Fetal Injury |
Ribavirin Nursing Considerations | Monitor CBC 1-2 weeks AFTER beginning therapy |
Direct Acting Anti-Viral Drugs (DAAs) | Four different categories, but some are active against HIV as well SubQ, PO Dosing |
Direct Acting Anti-Viral Drugs MOA | Prevents replication of HCV |
Direct Acting Anti-Viral Drugs Side Effects | Flu-like symptoms |
Direct Acting Anti-Viral Drugs Nursing Considerations | Monitor Liver Function Tests |
Renal Disorders | UTI, Overactive Bladder, Renal Failure (ESRD) |
Nitrofurantoin (Macrobid) | URINARY TRACT ANTISEPTIC For frequent UTIs. Oral dosing only |
Nitrofurantoin MOA | Bacteriostatic drug, damages bacterial DNA at low doses. Works against BOTH gram-positive and gram-negative bacteria |
Nitrofurantoin Side Effects | GI disturbances (nausea, vomiting, diarrhea) - for some patients Pulmonary reactions (Dyspnea, shortness of breath |
Oxybutynin (Ditropan XL) | BLADDER RELAXANT | ANTICHOLINERGIC-ANTIMUSCARININC DRUG Treats overactive bladder. Oral dosing |
Oxybutynin MOA | Inhibits bladder contractions Decreases the urge to void |
Oxybutynin Adverse Effects | Blurred vision Dry mouth Constipation |
Classes of Phosphate-Binding Drugs | Calcium-Based Calcium Free |
Os-Cal PhosLo | CALCIUM-BASED DRUG PO, taken TID (three times a day) |
Os-Cal | PhosLo MOA | Reduces phosphate absorption |
Os-Cal | PhosLo Side Effects | Promotes hypercalcemia (high levels of calcium) |
Sevelamer (Two Kinds: Sevelamer hydrochloride, Sevelamer carbonate) | CALCIUM-FREE DRUG PO, taken TID (three times a day). MORE EXPENSIVE |
Sevelamer MOA | Reduces phosphate absorption |
Sevelamer Side Effects | One type can cause metabolic acidosis (Sevelamer hydrochloride) |