Medications: Fluid Balance, Electrolytes, and More

• These notes cover various medications, their uses, side effects, and nursing considerations, focusing on fluid balance, electrolytes, nutrition, coagulation, cholesterol management, and gastrointestinal and central nervous system drugs.

Fluid Balance

• Isotonic fluids have the same concentration of fluid and particles as cells, maintaining cell size.
  • Examples: 0.9% NS, Lactated Ringers.
  • Used to replace fluids and sodium.
• Hypotonic fluids have a lower concentration, causing cells to swell.
  • Examples: 0.45% NS, 0.33% NS.
  • Used for DKA and to replace intracellular fluid.
• Hypertonic fluids have a higher concentration, causing cells to shrink.
  • Examples: 3% NS, 5% Dextrose in 0.45% NS ("D5 ½ NS"), 5% Dextrose in 0.9% NS ("D5NS"), 5% Dextrose in LR ("D5LR").
  • Used to increase serum osmolality, correct hyponatremia, and decrease ICP in cerebral edema.
• Fluid Volume Deficit (FVD) is corrected with isotonic IVF and oral fluid intake.
• Fluid Volume Excess (FVE) is managed with fluid restriction and diuretics.

Electrolytes

Hypokalemia

• Symptoms include low BP, low HR (thready pulse), muscle weakness, paresthesia, leg cramps, abdominal distension, potential paralytic ileus, arrhythmias, and confusion.
• Treated by replacing potassium through medication and potassium-rich foods (bananas, potatoes, tomatoes, avocado).
• Oral potassium should not be crushed, and IV potassium should be administered slowly via IVPB.

Hyperkalemia

• Symptoms include muscle weakness, decreased urinary output, respiratory failure, decreased cardiac contractility, early muscle twitches/cramps, and rhythm changes like tall peaked T waves and prolonged PR intervals.
• Treatment involves restricting potassium, addressing the cause, and using medications to remove potassium.

Hyponatremia

• Symptoms include headache, AMS, confusion, lethargy, coma, seizures, loss of urine, muscle weakness, and a weak/thready pulse.
• Management includes sodium replacement through diet and IVF (isotonic and hypertonic).

Hypernatremia

• Symptoms include agitation, tachycardia, HTN, N/V, flushed skin, extreme thirst, and a swollen, dry tongue (late sign).
• Treatment includes sodium restrictions and IVF.

Vitamins

• Vitamin D is essential for calcium absorption from the small intestine.
• Patients on anticoagulants should limit vitamin K intake.
• Vitamin C aids in iron absorption.
• Folic acid supplements are recommended during the first trimester of pregnancy.
• Vitamin B12 absorption requires intrinsic factor secreted by the stomach.
  • Cyanocobalamin is the drug form of vitamin B12.
• Iron is necessary for hemoglobin regeneration.
• Iron should be taken with orange juice and through a straw to avoid teeth staining; common side effects include constipation and dark stools.

Nutrition - Enteral & Parenteral

• Continuous enteral feeding delivers nutrition steadily, while bolus feeding delivers nutrition in multiple sessions.
• Aspiration is a significant risk; prevent by elevating HOB to 30-45 degrees, checking residuals, and confirming tube position with XRAY.
• When administering medications via enteral feeding tubes, ensure the drug is crushable and soluble in water, prepare each medication separately, crush and dissolve thoroughly, and flush with water between each.
• Parenteral nutrition (TPN) is delivered IV, bypassing the GI tract, via PICC or central line.
  • Suitable for patients with obstructions, those needing complete bowel rest (e.g., ulcerative colitis), or severe burn patients.
• Infection is a major concern due to direct entry of sugar/bacteria into the bloodstream, requiring bag and filter changes every 24 hours, refrigeration, and aseptic technique.
• Hyperglycemia can occur due to TPN ingredients or infusion rate; monitor blood sugar every 4-6 hours, and insulin may be added to the TPN bag.
• Hypoglycemia can result from interrupted therapy; D10 bag should be administered.
• TPN requires a weaning process when discontinuing.

Anticoagulants and Antiplatelets

• Anticoagulants prevent clot formation, while antiplatelets prevent platelet aggregation.
• Neither dissolves existing clots.

Heparin

• Administered SubQ or IV.
• Side effect: Bleeding.
• Antidote: Protamine sulfate.
• Monitor PTT, aPTT, and Xa labs.

Enoxaparin

• Administered via prefilled syringes, can be given at home by patients.
• Lower bleeding risk than heparin; aPTT/PTT monitoring is not required.
• Antidote: Protamine sulfate.

Warfarin

• Administered orally.
• Monitor PT/INR labs.
• Long half-life and duration; therapeutic adjustments take 3-5 days, tablets are color-coded.
• Antidote: Phytonadione (vitamin K).
• Interacts with vitamin K-rich foods (green leafy vegetables).
• May be discontinued before procedures, sometimes replaced with enoxaparin.

Factor Xa Inhibitors

• Examples: Rivaroxaban (Xarelto), apixaban (Eliquis), edoxaban, betrixaban.
• Critical bleeding is managed with fresh whole blood, fresh frozen plasma, or platelets.

Antiplatelet Drugs

• Examples: Aspirin, Clopidogrel (Plavix), Ticagrelor (Brilinta), Cilostazol (Pletal).
• Considerations include bleeding, salicylate toxicity, and Reye syndrome (aspirin).

Thrombolytics

• Dissolve existing blood clots.
• Ideal administration timeframe: within 3 hours for CVA, 3-4 hours for MI.
• Contraindications: Hemorrhagic stroke, recent surgery, bleeding disorders.
• Side effects: Bleeding, hypotension, fever.
• For occluded central lines, use the manufacturer's recommended amount of thrombolytic, leave 'packed' for the specified time, then aspirate, flush, and resume normal use.
• Antidote: Aminocaproic acid.

Cholesterol Management

• HMG-CoA reductase inhibitors are commonly known as statins.
• Niacin is a B vitamin used for hypercholesterolemia; a side effect is flushing.
• Fibrates lower triglyceride levels; side effects include GI issues, dizziness, and headache.
  • Examples: Fenofibrate, gemfibrozil.
• Bile acid sequestrants include cholestyramine and colesevelam, and have GI-related side effects like constipation and N/V.

Nausea/Vomiting

• Determine the cause due to risk of dehydration and electrolyte imbalances.
• OTC medications: Diphenhydramine (Benadryl), Meclizine (Antivert), bismuth subsalicylate (Pepto-Bismol).
• Prescription medications: Hydroxyzine (Vistaril), Scopolamine, Ondansetron (Zofran), promethazine, Metoclopramide (Reglan).
• Metoclopramide has antiemetic effects and stimulates the GI system post-op.
• Emetics induce vomiting but should be avoided with caustic or petroleum substances and when aspiration is a risk.

Diarrhea

• Notify if diarrhea persists for more than 48 hours or if acute abdominal pain develops; encourage clear liquid intake.
• Antidiarrheal medications: Bismuth subsalicylate (Pepto-Bismol), Diphenoxylate with atropine (Lomotil), Loperamide (Imodium).

Laxatives

• Osmotic/saline laxatives: Glycerin suppository, Lactulose, Magnesium citrate, Magnesium hydroxide (Mylanta, Milk of Mag), Polyethylene glycol (Miralax).
• Stimulant laxatives: Bisacodyl (Dulcolax) and Senna.
• Bulk-forming laxatives: Psyllium (Metamucil), Methylcellulose (Citrucel), Polycarbophil (Fibercon).
• Monitor stool frequency and consistency, F&E balance, and encourage fluid, fiber, and activity.
• Stool softeners: Docusate (Colace) and Mineral oil.
• Bowel prep/evacuant: Polyethylene glycol-electrolyte solution (GoLytely) used for colonoscopies.

Antacids

• Neutralize stomach acid already produced.
• Sodium bicarbonate can cause hypernatremia and metabolic alkalosis with excess use.
• Calcium carbonate can cause hypercalcemia, renal calculi, and constipation.
• Aluminum antacids can cause constipation.
• Magnesium antacids can cause diarrhea.
• Should not be taken with other medications (2 hours before or after); encourage drinking water.
• H2 blockers (e.g., Famotidine (Pepcid), Ranitidine) prevent reflux by blocking histamine release, reducing gastric acid secretion.
• PPIs (e.g., Omeprazole (Prilosec), Pantoprazole (Protonix)) inhibit an enzyme to suppress gastric acid secretion.
• Sucralfate is aluminum hydroxide combined with sucrose.

CNS Stimulants

• Commonly prescribed for ADHD and narcolepsy.
• Controlled substances due to high abuse potential.
• Take as prescribed, monitor vital signs, and be mindful of caffeine intake.
• Commonly prescribed stimulants: Amphetamine or dextroamphetamine, Methylphenidate, Modafinil, armodafinil.
• Common side effects: Restlessness, tremors, irritability, tachycardia, palpitations, and HTN.
• Monitor HR and BP in patients taking stimulants.