The adverse effects of the Exam 3 lectures sorted the way Dr. Wood sorts them. 38 entries.
Dangerous. Immediate discontinuation and evaluation. Not necessarily common: these are the ones you warn the patient about in advance.
| Effect | Drug or class | What it means / what to do | Source |
|---|---|---|---|
| Hyperkalemia | Potassium-sparing diuretics (amiloride, triamterene) | The defining danger of the class. Caution when combined with angiotensin-converting enzyme inhibitors, angiotensin receptor blockers or potassium supplements. (Added background: both agents carry a Food and Drug Administration (FDA) boxed warning for hyperkalemia; salt substitutes are usually potassium chloride.) | L9 slide 33 |
| Hyperkalemia with mild acidosis | Aldosterone antagonists (spironolactone, eplerenone) | Holding on to potassium is the point of the drug and also its danger. Heart failure patients are not eligible when potassium is high or creatinine is high; kidney dysfunction makes it more likely. | L9 slide 38 |
| Hypokalemia with cardiac arrhythmias | Loop diuretics | Loops increase potassium excretion. Know every drug's effect on potassium: low potassium is what makes arrhythmias, and digoxin toxicity, more likely. | L9 slide 18 |
| Hypokalemia | Thiazide diuretics | Thiazides increase potassium and magnesium excretion. With digoxin, keep potassium above 4.0 milliequivalents per liter. | L9 slide 26 |
| Profound volume depletion, circulatory collapse | Loop diuretics | Too much sodium loss means volume depletion and cardiovascular collapse; the loop is the most potent class, so it carries the most risk. (Added background: furosemide, bumetanide and ethacrynic acid carry an FDA boxed warning for profound diuresis with water and electrolyte depletion.) | L9 slide 18 |
| Hyponatremia with seizures | Loop diuretics | Sodium loss severe enough to cause seizures is a listed adverse effect. | L9 slide 18 |
| Digoxin toxicity: any arrhythmia, most often bradycardia | Digoxin | Toxicity slows nodal conduction (longer PR interval, shorter QT interval, depressed ST segment) and can cause digoxin-induced after-depolarizations, so ventricular arrhythmias occur. A level is checked when toxicity is suspected. | L9 slide 70 |
| Digoxin toxicity made likelier by electrolyte disturbance | Digoxin with loop diuretics, thiazides (low potassium, low magnesium) and with high calcium | Low potassium, low magnesium and high calcium raise the risk. Loops and thiazides lower potassium and magnesium, so a patient on both is at risk. (Added background: it is low potassium that raises digoxin toxicity risk; high potassium is not a risk factor for toxicity.) | L9 slide 71 |
| Ventricular arrhythmias, thrombocytopenia, higher long-term mortality | Milrinone, inamrinone | Approved for short-term intravenous use only; long-term use is associated with higher mortality and morbidity than placebo. Thrombocytopenia is less with milrinone. | L9 slide 76 |
| Worsening heart failure on starting | Beta blockers in heart failure | Classically considered contraindicated in heart failure. The patient must be stable first, start with very low doses, titrate up slowly and be watched for worsening signs. (Added background: never stop abruptly.) | L9 slide 57 |
| Overlapping adverse effects, and fetal toxicity | Sacubitril-valsartan with an angiotensin-converting enzyme inhibitor | Never combine; allow a 36 hour washout when switching. The overlap brings hypotension, hyperkalemia, cough and renal insufficiency. (Added background: valsartan gives the product an FDA boxed warning for fetal toxicity; a history of angioedema also bars it.) | L9 slide 81 |
| Unmasked heart failure or atrial fibrillation after reversal | Digoxin immune Fab (antidote) | Binds digoxin rapidly and reverses toxicity; the condition digoxin was treating can return, so watch rhythm and fluid status. | L9 slide 72 |
What actually happens, often. These belong to the class, not the drug, so they are listed by class.
| Effect | Drug or class | What it means / what to do | Source |
|---|---|---|---|
| Hypokalemia, hypocalcemia, hypomagnesemia | Loop diuretics (class effect) | Loops raise urinary potassium, calcium and magnesium losses; check these electrolytes. | L9 slide 13 |
| Hypokalemia, magnesium loss, and reduced calcium excretion | Thiazide diuretics (class effect) | Thiazides lose potassium and magnesium but hold on to calcium, the opposite of the loops. | L9 slide 22 |
| Hyperglycemia | Loop diuretics, thiazide diuretics | Impaired insulin release (low potassium, catecholamine release, insulin resistance); watch blood sugar in diabetes. | L9 slide 18 |
| Hyperuricemia and gout | Loop diuretics, thiazide diuretics | Volume contraction concentrates uric acid and less is excreted; a gout history is a caution. | L9 slide 18 |
| Contraction (metabolic) alkalosis | Loop diuretics, thiazide diuretics | Volume depletion with enhanced hydrogen ion secretion raises the pH. Carbonic anhydrase inhibitors do the opposite (acidosis). | L9 slide 18 |
| Volume depletion with reflex activation of the renin-angiotensin system, aldosterone and antidiuretic hormone | Loop diuretics, thiazide diuretics | The kidney fights the diuretic (the braking effect), which is why diuretics combine well with agents that block these systems. | L9 slide 15 |
| Azotemia (rise in blood urea nitrogen) | Loop diuretics | Volume contraction raises blood urea nitrogen; kidney function is monitored. | L9 slide 18 |
| Mild hypercalcemia (with fewer calcium stones), hyperlipidemia, rash, photosensitivity | Thiazide diuretics | A small rise in serum calcium while urinary calcium falls, so calcium stones are less likely; low-density lipoprotein (LDL) cholesterol rises modestly. | L9 slide 27 |
| Dizziness, headache, weakness, restlessness, sexual dysfunction, constipation | Thiazide diuretics | Common and mild; counsel the patient. | L9 slide 27 |
| Nausea, vomiting, gastrointestinal upset | Aldosterone antagonists | Listed with hyperkalemia as the common adverse effects of the class. | L9 slide 38 |
| Metabolic acidosis, potassium depletion, drowsiness | Carbonic anhydrase inhibitors | Bicarbonate is lost, so the blood becomes acidic (unlike other diuretics); the drug also causes potassium loss and drowsiness. | L9 slide 43 |
| Cough, hypotension, impaired renal function, high potassium | Angiotensin-converting enzyme inhibitors in heart failure | The common problems; angioedema is the rare one. Check renal function and potassium. | L9 slide 56 |
| Anorexia, nausea; fatigue, confusion, dizziness, abnormal dreams | Digoxin toxicity | The early gastrointestinal and central signs that a level is too high. | L9 slide 68 |
| Hypotension | Sodium-glucose cotransporter 2 inhibitors | Volume is lost with the glucose; blood pressure can fall. | L9 slide 82 |
| Hypotension, hyperkalemia, cough, renal insufficiency | Sacubitril-valsartan | The most common adverse effects of the combination. | L9 slide 81 |
Uncommon, but unique to one drug. Each is worth about one question, and with the killers they are where to look.
| Effect | Drug or class | What it means / what to do | Source |
|---|---|---|---|
| Gynecomastia and testicular atrophy in men; menstrual irregularities and hirsutism in women | Spironolactone | Acts at androgen (testosterone) receptors; the course calls it a weak partial agonist, but in current pharmacology it blocks them. Eplerenone has less effect on androgen receptors, so it is the switch when these occur. Hirsutism is listed on the source but is not a typical effect; spironolactone treats it. | L9 slide 38 |
| Megaloblastic anemia | Triamterene | Unique to triamterene among the potassium-sparing diuretics. | L9 slide 33 |
| Azotemia | Amiloride | Specific to amiloride among the potassium-sparing diuretics. | L9 slide 33 |
| Xanthopsia: yellow-green halos, blurred vision, photophobia | Digoxin | Visual disturbance is the classic clue of too much digoxin; check a level. | L9 slide 68 |
| Ototoxicity (hair cell damage in the cochlea) | Loop diuretics (greater with aminoglycosides) | Hearing damage; an aminoglycoside given together potentiates it. | L9 slide 18 |
| Lithium retention and toxicity | Loop diuretics | Lithium clearance falls, so lithium toxicity can follow. | L9 slide 19 |
| Phosphenes (visual impairment from retinal photoreceptor effects), atrial fibrillation, symptomatic bradycardia | Ivabradine | Transient brightness in a limited area of the visual field, halos and multiple images; it often resolves on its own. Contraindications resemble those of beta blockers. | L9 slide 80 |
| Fungal urinary tract infections (and genital yeast infections) | Sodium-glucose cotransporter 2 inhibitors (dapagliflozin, empagliflozin) | Glucose is lost in the urine, which fungi use. (Added background: genital yeast infections are the more typical form.) | L9 slide 82 |
| Metabolic acidosis (a diuretic that acidifies) | Carbonic anhydrase inhibitors (acetazolamide) | Unique among diuretics: bicarbonate loss acidifies the blood; this is also the reason for its use in epilepsy and mountain sickness. | L9 slide 43 |
| Thrombocytopenia | Inamrinone (milrinone causes less) | Platelet count is followed with these agents. | L9 slide 76 |
| Angioedema | Angiotensin-converting enzyme inhibitors | Rare but serious swelling of the lips and airway; stop the drug. | L9 slide 56 |