NUR 2420 Pharmacology: Fluids, Electrolytes, Renal, Urinary, and Metabolism

Comprehensive vocabulary flashcards covering diuretics, fluid and electrolyte balance, urinary elimination, kidney disorders, insulins, non-insulin antidiabetics, thyroid hormones, and adrenal therapies for NURS 2420.

Oxybutynin (Ditropan)

An anticholinergic urinary antispasmodic that blocks muscarinic acetylcholine receptors in bladder smooth muscle, decreasing involuntary detrusor contractions and increasing bladder capacity. Side effects include dry mouth, constipation, dizziness, and blurred vision. It is contraindicated in narrow-angle glaucoma, urinary retention, gastric retention, and benign prostatic hyperplasia (BPH).

Mirabegron (Myrbetriq)

A beta-3 adrenergic agonist that stimulates beta-3 receptors on the bladder detrusor muscle, activating a Gs protein pathway to increase cyclic AMP ($\text{cAMP}$) and relax the detrusor muscle during storage, thereby increasing bladder capacity. Blood pressure must be monitored before and during therapy because it can cause hypertension; facial swelling (angioedema) is an uncommon but serious danger.

Muscarinic Receptor Antagonists (Tolterodine, Solifenacin)

Urinary antispasmodic agents indicated for overactive bladder with urgency, frequency, and urge incontinence that block muscarinic receptors to reduce involuntary detrusor contractions. Nursing considerations include monitoring for anticholinergic burden and cognition in older adults, swallowing extended-release forms intact, and recognizing acute angle-closure glaucoma symptoms as an emergency.

Alpha-1 Adrenergic Blockers (Tamsulosin, Silodosin)

Urinary-flow agents for benign prostatic hyperplasia (BPH) that block alpha-1 receptors in prostate and bladder-neck smooth muscle, relaxing the outlet to improve urine flow without shrinking the prostate. Adverse effects include orthostatic hypotension, syncope, and Intraoperative Floppy Iris Syndrome (IFIS). Tamsulosin is taken about $30\,\text{min}$ after the same meal each day.

Intraoperative Floppy Iris Syndrome (IFIS)

A surgical complication occurring during cataract surgery in patients exposed to alpha-1 adrenergic receptor antagonists (such as tamsulosin or doxazosin), caused by relaxation of the iris dilator muscle.

5-Alpha Reductase Inhibitors (Finasteride, Dutasteride)

Androgen inhibitors that block the conversion of testosterone to dihydrotestosterone (DHT), gradually shrinking prostate epithelial tissue over $3\text{ to }6\,\text{months}$ to treat BPH (with finasteride also indicated at a lower dose for male-pattern hair loss). These medications are teratogenic; pregnant individuals must never handle crushed tablets or leaking capsules.

Phosphodiesterase-5 (PDE-5) Inhibitors (Sildenafil, Tadalafil, Vardenafil)

Vasodilators that inhibit PDE-5, increasing $\text{cGMP}$ and smooth-muscle relaxation to enhance penile blood flow during sexual stimulation (tadalafil also treats BPH). They are strictly contraindicated with nitrates or guanylate-cyclase stimulators due to profound, potentially fatal hypotension. Priapism persisting $> 4\,\text{hours}$ requires emergency care.

Spironolactone

A potassium-sparing diuretic that blocks aldosterone receptors in the distal nephron, promoting sodium and water excretion while retaining potassium. The primary safety concern is hyperkalemia; patients must avoid potassium supplements, salt substitutes, and potassium-retaining agents like ACE inhibitors/ARBs unless specifically prescribed.

Furosemide (Lasix)

A potent loop diuretic that blocks $\text{Na}^+/\text{K}^+/2\text{Cl}^-$ reabsorption in the thick ascending limb of the loop of Henle, causing marked diuresis and electrolyte excretion. Major adverse effects include severe volume depletion, hypokalemia, hyponatremia, and ototoxicity (especially with rapid IV administration).

Hydrochlorothiazide (HCTZ)

A thiazide diuretic derivative of sulfa that inhibits sodium chloride cotransport in the distal convoluted tubule. It promotes excretion of sodium, water, potassium, and magnesium while decreasing urinary calcium excretion. Adverse effects include hypokalemia, hyponatremia, hypercalcemia, hyperglycemia, and hyperuricemia/gout flares.

Mannitol (Osmitrol)

An osmotic diuretic administered intravenously that raises plasma and tubular osmotic pressure, drawing water from intracellular and interstitial spaces (such as swollen brain tissue or the eye) into the intravascular space to reduce increased intracranial pressure (ICP) and intraocular pressure (IOP). It can precipitate pulmonary edema or heart failure and is contraindicated in anuria.

Calcium Salts (Calcium Carbonate, Calcium Citrate)

Oral calcium replacements used for hypocalcemia prevention, osteoporosis, and as an antacid (carbonate). Calcium carbonate requires stomach acid and must be taken with food, whereas calcium citrate is absorbed independently of gastric acid and can be taken with or without food. Both must be separated from levothyroxine, iron, and tetracyclines by at least $2\text{ to }4\,\text{hours}$.

Potassium Chloride (KCl)

An electrolyte replacement used to treat and prevent hypokalemia. It must NEVER be administered via IV push or bolus because rapid infusion causes fatal cardiac dysrhythmias and arrest. Oral formulations should be taken with meals and a full glass of water, and extended-release tablets must not be crushed.

Magnesium Sulfate

A mineral electrolyte used for hypomagnesemia, prevention/treatment of eclamptic seizures, and ventricular dysrhythmias such as torsades de pointes. Toxicity manifests as loss of deep tendon reflexes (DTRs), respiratory depression, severe hypotension, and bradycardia. Its specific reversal antidote is calcium gluconate.

Calcium Gluconate

An intravenous calcium salt utilized to stabilize cardiac cell membranes in severe hyperkalemia or hyperkalemia with ECG changes, and administered as the direct emergency antidote for severe magnesium toxicity.

Calcium Acetate (PhosLo)

A calcium-based phosphate binder indicated for hyperphosphatemia in end-stage renal disease (ESRD) and chronic kidney disease (CKD) on dialysis. It binds dietary phosphorus in the intestinal lumen to form insoluble calcium phosphate excreted in feces, and must always be taken with meals.

Sodium Bicarbonate

A systemic and urinary alkalinizing agent used to correct metabolic acidosis and alkalinize urine. Potential complications include metabolic alkalosis, hypokalemia, hypernatremia, and fluid overload due to its high sodium content.

Sodium Polystyrene Sulfonate (Kayexalate)

A cation-exchange resin that exchanges sodium ions for potassium ions in the large intestine, eliminating potassium via the feces to treat non-emergent hyperkalemia. It has a slow onset of action and is never used as the sole treatment for life-threatening hyperkalemia with ECG changes; it carries a rare risk of intestinal necrosis.

Water-Soluble Vitamins (B-Complex, Vitamin C)

Essential organic nutrients that dissolve in water, are not readily stored in large quantities in the body, and have excess amounts excreted in the urine. B vitamins function as metabolic coenzymes and support hematopoiesis, while vitamin C serves as an antioxidant and promotes collagen synthesis and iron absorption.

Fat-Soluble Vitamins (Vitamins A, D, E, K)

Vitamins stored in adipose tissue and the liver that can accumulate and produce hypervitaminosis toxicity when taken in excess. Vitamin A supports vision and epithelial health, vitamin D enhances calcium and bone mineralization, vitamin E provides antioxidant activity, and vitamin K is required for hepatic clotting factor synthesis.

Ferrous Sulfate

An oral iron supplement for iron-deficiency anemia that provides elemental iron for hemoglobin production. Expected side effects include dark green or black stools and constipation. It is best absorbed on an empty stomach with acidic fluids (such as vitamin C/orange juice), and liquid forms must be sipped through a straw to prevent tooth staining.

Deferoxamine

A chelating agent administered parenterally as the specific antidote for acute iron overdose and iron toxicity.

Colloids (Albumin, Dextran)

Intravenous volume expanders containing large, high-molecular-weight particles (such as proteins) that do not readily cross intact capillary walls. They remain inside the vascular compartment, increasing oncotic pressure to pull fluid from the interstitial space into the bloodstream.

Crystalloids

Aqueous IV solutions composed of water and small, freely permeable solute particles (electrolytes) that cross capillary membranes easily and distribute into the entire extracellular fluid compartment (both intravascular and interstitial spaces).

Tonicity

The osmotic effect that an extracellular solution's solute concentration exerts on water movement across semipermeable cell membranes: solutions with $< 0.9\%\,\text{NaCl}$ are hypotonic (water moves into cells), solutions with $0.9\%\,\text{NaCl}$ are isotonic (no major fluid shift), and solutions with $> 0.9\%\,\text{NaCl}$ are hypertonic (water moves out of cells).

5% Dextrose in Water (D5W)

An intravenous crystalloid solution with an osmolality of approximately $260\,\text{mOsm/L}$ that is isotonic in the infusion bag, but becomes physiologically hypotonic in the body once the dextrose is rapidly metabolized, providing free water to cells. It is contraindicated in elevated ICP and CHF.

Hypertonic Crystalloid Solutions (3% NaCl, D5NS, D5LR)

IV fluids with an osmolality significantly higher than normal plasma osmolality ($> 300\,\text{mOsm/L}$) that pull fluid out of swollen cells and interstitial spaces into the vascular system. Indications include severe symptomatic hyponatremia and cerebral edema; they require close monitoring to avoid hypernatremia, rapid sodium overcorrection, and pulmonary edema.

Hypotonic Crystalloid Solutions (0.45% NaCl, 0.33% NaCl)

IV solutions with an osmolality lower than plasma that cause water to move from the extracellular space into dehydrated cells. Used for hypertonic dehydration and cellular dehydration states, but contraindicated in increased intracranial pressure (ICP), burns, and trauma due to risk of cerebral edema and cellular swelling.

Isotonic Crystalloid Solutions (0.9% NaCl, Lactated Ringer's)

IV fluids with an osmolality matching normal plasma ($270\text{ to }300\,\text{mOsm/L}$) that expand extracellular volume without causing net water shifts into or out of cells. Normal saline ($0.9\%\,\text{NaCl}$) is used for volume resuscitation; Lactated Ringer's contains sodium, potassium, calcium, and lactate (metabolized to bicarbonate by the liver).

Saw Palmetto

An herbal supplement utilized to reduce mild-to-moderate symptoms of benign prostatic hyperplasia (BPH) through an unknown mechanism of action. Patients taking saw palmetto should not combine it with prescription BPH medications without prescriber supervision.

Rapid-Acting Insulins (Lispro, Aspart, Glulisine)

Mealtime insulins with an onset of approximately $10\text{ to }30\,\text{min}$, peak of $0.5\text{ to }3\,\text{hours}$, and duration of $3\text{ to }5\,\text{hours}$. They must be administered only when food is immediately present or ready to consume to prevent acute hypoglycemia.

Short-Acting Insulin (Regular Insulin)

A mealtime and intravenous insulin (Humulin R, Novolin R) with an onset of $30\text{ to }60\,\text{min}$, peak of $2\text{ to }4\,\text{hours}$, and duration of $5\text{ to }8\,\text{hours}$. It is the classical insulin given intravenously for diabetic ketoacidosis (DKA) and hyperkalemia protocols; when mixed with NPH, clear (regular) is drawn before cloudy (NPH).

Intermediate-Acting Insulin (NPH Insulin)

A basal suspension insulin (Humulin N, Novolin N) with a cloudy appearance, onset of $1\text{ to }2\,\text{hours}$, a distinct peak at $4\text{ to }12\,\text{hours}$, and duration of $12\text{ to }18\,\text{hours}$. It carries an increased risk of hypoglycemia during its peak action window and must be rolled gently, never vigorously shaken.

Long-Acting Insulins (Glargine, Detemir, Degludec)

Basal insulins providing steady, prolonged 24-hour glycemic control with little to no pronounced peak. They must NEVER be mixed in the same syringe with any other insulin, and are not intended for acute mealtime correction.

Pramlintide (Symlin)

A synthetic amylinomimetic peptide co-administered subcutaneously immediately before major meals in type 1 or type 2 diabetes. It slows gastric emptying, suppresses postprandial glucagon secretion, and increases satiety; it must never be mixed in the same syringe as insulin, and mealtime insulin doses are typically reduced to avoid severe hypoglycemia.

Sulfonylureas (Glipizide, Glyburide)

Oral insulin secretagogues that stimulate functional pancreatic beta cells to release insulin regardless of ambient blood glucose levels. Key risks are hypoglycemia and weight gain; patients must take them before eating and never skip meals after dosing.

Metformin (Glucophage)

A first-line biguanide for type 2 diabetes that decreases hepatic glucose production, enhances peripheral insulin sensitivity, and does not stimulate insulin release. It carries a boxed warning for rare but serious lactic acidosis; renal function ($\text{eGFR}$) must be verified, and it is withheld before iodinated radiocontrast procedures.

Thiazolidinediones / TZDs (Pioglitazone, Rosiglitazone)

Peroxisome proliferator-activated receptor-gamma ($\text{PPAR}-\gamma$) agonists that enhance insulin sensitivity in adipose tissue and skeletal muscle. They cause fluid retention and weight gain, and are contraindicated or used with extreme caution in patients with heart failure.

Alpha-Glucosidase Inhibitors (Acarbose, Miglitol)

Oral antidiabetic agents that competitively inhibit alpha-glucosidase enzymes in the brush border of the small intestine, delaying carbohydrate breakdown and blunting postprandial glucose spikes. They must be taken with the first bite of each main meal; if hypoglycemia occurs, it must be treated with pure glucose (dextrose), not sucrose (cane sugar).

DPP-4 Inhibitors (Sitagliptin, Saxagliptin, Linagliptin)

Oral incretin enhancers that inhibit dipeptidyl peptidase-4, prolonging active GLP-1 levels to stimulate glucose-dependent insulin release and decrease post-meal glucagon. They are weight-neutral with low hypoglycemia risk, but carry warnings for acute pancreatitis and heart failure (especially saxagliptin). Linagliptin requires no renal dose adjustment.

Meglitinides (Repaglinide, Nateglinide)

Short-acting, meal-related insulin secretagogues that stimulate rapid, brief insulin release from pancreatic beta cells. They must be taken within $15\text{ to }30\,\text{min}$ before meals; if a meal is skipped, the scheduled dose must also be skipped.

SGLT2 Inhibitors (Dapagliflozin, Empagliflozin)

Antidiabetic agents that inhibit sodium-glucose cotransporter 2 in the proximal renal tubules, promoting glucosuria and mild osmotic diuresis to lower blood glucose and provide cardiorenal protection. Notable adverse effects include genital mycotic infections, urinary tract infections, volume depletion, and euglycemic diabetic ketoacidosis (euDKA).

GLP-1 Receptor Agonists (Semaglutide, Liraglutide, Tirzepatide)

Incretin mimetics (and dual GIP/GLP-1 agonist tirzepatide) that increase glucose-dependent insulin secretion, suppress inappropriate glucagon release, delay gastric emptying, and promote satiety and weight loss. Major adverse effects include nausea, vomiting, pancreatitis, and gallbladder disease; they carry a boxed warning against use in patients with a history of medullary thyroid carcinoma (MTC) or MEN2.

Glucagon

An antihypoglycemic pancreatic hormone indicated for severe, acute hypoglycemia in unconscious or impaired patients unable to swallow oral carbohydrates. It stimulates hepatic glycogenolysis to mobilize glucose stores; an unconscious patient should be placed in a side-lying recovery position to prevent pulmonary aspiration if vomiting occurs.

Levothyroxine (Synthroid, Levoxyl)

A synthetic isomer of thyroxine ($\text{T}_4$) that restores metabolic activity in hypothyroidism. It must be taken on an empty stomach with a full glass of water $30\text{ to }60\,\text{min}$ before breakfast, separated from calcium, iron, and antacids by about $4\,\text{hours}$. Over-replacement causes tachycardia, tremors, heat intolerance, and dysrhythmias.

Antithyroid Medications (Methimazole, Propylthiouracil / PTU)

Thionamide agents that inhibit thyroid peroxidase, preventing the synthesis of $\text{T}_3$ and $\text{T}_4$ (PTU also blocks peripheral $\text{T}_4\text{-to-}\text{T}_3$ conversion). Patients must report fever and sore throat immediately due to the risk of agranulocytosis; PTU carries a boxed warning for severe hepatotoxicity.

Fludrocortisone (Florinef)

A potent synthetic mineralocorticoid used as aldosterone replacement therapy in primary adrenal insufficiency (Addison disease). It enhances renal sodium and water reabsorption while accelerating potassium and hydrogen excretion, requiring monitoring for hypertension, peripheral edema, and hypokalemia.

Anticholinergic Toxidrome Mnemonic

A clinical mnemonic describing muscarinic blockade toxicity: 'Mad as a hatter' (confusion, delirium, agitation), 'Blind as a bat' (mydriasis, blurry vision), 'Red as a beet' (flushed, warm skin), 'Hot as a hare' (hyperthermia from anhidrosis), and 'Dry as a bone' (dry mucous membranes and urinary retention).

Calcitriol

The active form of vitamin D ($1,25\text{-dihydroxycholecalciferol}$) that promotes enteral absorption of calcium and phosphorus; used in chronic kidney disease to manage hypocalcemia and secondary hyperparathyroidism, requiring ongoing surveillance for hypercalcemia.

Epoetin Alfa

An erythropoiesis-stimulating agent that mimics endogenous erythropoietin to stimulate red blood cell production in the bone marrow, treating anemia associated with chronic kidney disease. Key risks include hypertension, vascular graft occlusion, and thromboembolic events; hemoglobin and iron stores must be tracked.

Hypoglycemia Rule of 15

A standardized protocol for treating hypoglycemia in conscious patients who can swallow: administer $15\,\text{g}$ of fast-acting simple carbohydrate (e.g., $4\,\text{oz}$ fruit juice, glucose tablets), wait $15\,\text{min}$, and recheck blood glucose; repeat the cycle if glucose remains below target range ($< 70\,\text{mg/dL}$).