Diuretics, HR, Antidysrhythmic Flashcards
Thiazide Diuretics
hydrochlorothiazide (HCTZ)
-K+ wasting
Hyrdrochlorothiazide (HCTZ)
MOA
Inhibits resorption of Na+, K+, & Cl: results in osmotic water loss
Hyrdrochlorothiazide (HCTZ) Indications
thiazide diuretic
Edema Adjuncts in treatment in HF Diabetes insipidus Hypertension Idiopathic hypercalciuria (excess CA+ in urine)
Hyrdrochlorothiazide (HCTZ) Contraindications
Thiazide diuretic
Allergy Hepatic coma Anuria Severe renal failure (These patients already have electrolyte imbalances)
Hyrdrochlorothiazide (HCTZ) AE’s
Related to electrolyte & metabolic disturbances they cause: Hypokalemia Hypercalcemia Hyperglycemia Elevated lipids Uric acid levels Hyponatremia? Dehydration
Hyrdrochlorothiazide (HCTZ) Interactions
Corticosteroids
Digoxin
Oral hypoglycemic drugs
Potassium-Sparing Diuretics
Spironolactone (Aldactone)
Spironolactone (Aldactone) MOA
Interfere with sodium-potassium exchange
works in the collecting ducts & distal convoluted tubules
Spironolactone (Aldactone) Indications
K+-sparing diuretic
- Hyperaldosteronism
- Hypertension
- Hypokalemia caused by K+-wasting diuretics
- HF in Pediatric patients
Spironolactone (Aldactone) Contraindications
- Hyperkalemia
- Severe renal failure
- Anuria
- Allergy
Spironolactone (Aldactone) AE’s
K+-sparing diuretic
- Gynecomastia (male swollen breast tissue
- Amenorrhea (absence of period)
- Irregular menses
- Postmenopausal bleeding
- Hyperkalemia
- Dizziness
- HA
Spironolactone (Aldactone) Interactions
K+-sparing diuretic
- ACE inhibitors
- Lithium (increased lithium)
- NSAIDs (more bleeding)
Loop Diuretics
furosemide (Lasix)
furosemide (Lasix) MOA
Block chloride & Na+ resorption
Renal, cardiovascular & metabolic effects
furosemide (Lasix) Indications
- Edema
- HF
- hepatic & renal disease
- Hypertension
- Hypercalcemia
furosemide (Lasix) Contraindications
Loop diuretic
- Hepatic coma
- Severe electrolyte loss
- Allergy
furosemide (Lasix) AE’s
- Hypokalemia
- Photosensivity
- Dizziness
- HA
furosemide (Lasix) Interactions
- NSAIDs
- vancomycin
- corticosteroids
- digoxin
- lithium
- aminoglycoside antibiotics
Toxicity & overdose of hydrochlorothiazide & furosemide (Lasix)
K+ wasting =hypokalemia:
- alkalosis
- shallow respirations
- irritability
- confusion
- weakness
- arrhythmias
- lethargy
- thready pulse
- decreased intestinal motility
Toxicity & overdose of spironolactone (aldactone)
K+-sparing = hyperkalemia:
- muscle twitches, cramps, paresthesia
- Irritability & anxiety
- Decreased BP
- EKG changes
- Dysrhythmias
- Abdominal cramping
- Diarrhea
Heart Failure drugs
- Cardiac Glycosides: (digoxin)
2. Phosphodiesterase inhibitors (Milrinone)
Older Adults & Diuretics
Effects of diuretics are typically more exaggerated in older adults
Start with lower doses and gradually increase
Monitor for s/s of hyperkalemia, hypokalemia, dehydration
Change positions slowly
Have alternate methods for urination available (i.e. bedside commode, urinal)
Drug classes for Heart Failure
- Angiotensin-converting enzyme inhibitors (ACE) inhibitors
- Angiotensin receptor blockers (ARBs)
- Beta blockers
- Loop diuretics
- Remember, cardiac glycosides (i.e. digoxin) are used last!
Inotropic Drugs
Force of contraction
- (Positive) Increase force of myocardial contraction
- (Negative) Reduce force of contraction
Chronotropic Drugs
Heart Rate
- (Positive) increase HR
- (Negative) decrease HR
Dromotropic Drugs
Conduction
- (Positive) accelerate conduction
- (Negative) slow down conduction
Cardiac Glycoside
digoxin (Lanoxin)
digoxin (Lanoxin) MOA
Positive inotropic effect (increase force of contraction)
Negative chronotropic effect (Decreased HR)
Negative dromotropic effect (decreased conduction)
digoxin (Lanoxin) Indications
systolic HF
atrial fibrillation
digoxin (Lanoxin) Contraindications
- 2nd/3rd degree heart block
- ventricular tachycardia & fibrillation
- diastolic HF
- subaortic astenosis
- Allergy
digoxin (Lanoxin) AE’s
- bradycardia or tachycardia
- hypotension
- HA
- fatigue
- confusion
- convulsions
- colored vision, halo vision
- anorexia
- N/V/D
digoxin (Lanoxin) Interactions
-Amiodarone
-quinidine
-verapamil
These drugs increase digoxin levels by 50%!
Digoxin normal therapeutic levels
- 5-2 mg/mL
- Low K+/Mg levels may increase potential for digoxin toxicity
digoxin (Lanoxin) Toxicity S/S
- bradycardia
- HA
- Dizziness
- Confusion
- Nausea
- Visual disturbances (blurred or yellow)
digoxin (Lanoxin) Antidote
digoxin immune Fab
Who is at increased risk of digoxin toxicity?
- Older adults
2. Hypokalemia
digoxin (Lanoxin) toxicity management
- Discontinue drug
- Begin ECG monitoring -give antidysrhythmic meds as ordered
- Determine serum digoxin & electrolyte levels
- Administer K+ supplements for hypokalemia
- Institute supportive therapy for GI symptoms
- Administer digoxin immune Fab
Phosphodiesterase inhibitors:
Milrinone (Primacor)
Milrinone (Primacor) MOA
Positive inotropic (increases force of contraction) Causes vasodilation
Milrinone (Primacor) Indications
used in intensive care setting for short-term management of acute HF
Milrinone (Primacor) contraindications
- severe aortic or pulmonary vascular disease
- HF caused by diastolic dysfunction
- Allergy
Milrinone (Primacor) AE’s
- Ventricular dysrhythmias occur in 12%
- Hypotension
- Angina
- Hypokalemia
- tremor
- Thrombocytopenia
Milrinone (Primacor) interactions
- diuretics-may cause hypovolemia & reduced cardiac filling pressure
- Additive inotropic effects when also taking digoxin
Milrinone (Primacor) Nursing Considerations
- Most often used in ICU setting for acutely ill HF
- Monitor tele for ventr. dysr
- IV Pump
- Do not give in same line IV line as other drugs
Antidysrhythmic:
Class 1A Sodium channel blockers
quinidine (Quinide)
quinidine (Quinide) MOA
Blocks entry of Na+ into cardiac cells causing slower impulse conduction, decreased automaticity of ventricles & longer resting period
quinidine (Quinide) Indications
Atrial Fibrillations
Atrial Flutter
quinidine (Quinide) Contarindications
- Severe heart block
- Severe HF
- Asthma
- Myasthenia gravis
- low WBCs
quinidine (Quinide) AE’s
- GI
- Hypotension
- Ventricular dysrhythmia (toxicity)
- Arterial embolism
- cinchonism (tinnitus, visual disturbances, HA, N/V)
quinidine (Quinide) Interactions
- Anticholinergics
- Antidysrhymics
- Cholinergics
- Antihypertensives
- Digoxin
- Grapefruit
Antidysrhythmic Drugs
- quinidine (Quinidex) 1A Sodium channel blocker
- Flecainide (Tambacor) 1C sodium channel blocker
- amiodarone (Cordarone, Pacerone) 3 potassium channel blocker
- verapamil (Calan) IV Calcium Channel Blocker
- adenosine (Adenocard) unclassified
quinidine Interventions
- Monitor HR, BP, GI symptoms
- Keep patient supine during IV therapy (ortho hypo)
- Monitor ECG
- Monitor blood levels for toxicity
- Use an IV pump for
- Monitor & report s/s of cinhonism
flecainide (Tambocor) MOA
Sodium channel blocker
Blocks entry of Na+ into cardiac cells
flecainide (Tambocor) Indications
- Serious supraventricular & ventricular tachydysrhythmias not controlled by other drugs
- Used long-term for some supraventricular dysrhythmias
flecainide (Tambocor) Contraindications
- 2nd/3rd degree AV block
- Prolonged QT interval
- Recent MI
- Shock
- Electrolyte Imbalance
flecainide (Tambocor) AEs
- Blurry vision (difficulty focusing)
- Worsening of HF
- Edema
- Widening of QRS complex
- Potential for 1st degree AV block & multiple dysrhythmias
flecainide (Tambocor) Interactions
- Digoxin
- beta blockers
- Calcium channel blockers
flecainide (Tambocor) Interventions
- Monitor for & report visual changes
- Monitor for crackles in lungs, edema, weight gain
- Monitor ECG
- Monitor blood levels to detect toxicity
- Oral use only!
- Begin w. lowest dose & gradually increase no more than every 4 days
amiodarone (cordarone, pacerone)
Potassium channel blocker MOA
Block K+ channels, decrease automaticity, decrease contractility, & dilates coronary and peripheral vessels
Widens QRS complex, prolongs both PR & QT intervals
amiodarone (cordarone, pacerone) Indications
Manage life-threatening ventricular tachycardia or fibrillation that is resistant to other drugs
Treats Atrial fib
amiodarone (cordarone, pacerone) Contraindications
- Pregnancy
- Lactation
- Shock
- Bradycardia
- Heart block
- sinus node dysfunction
- Severe hepatic disease
- Allergy
amiodarone (cordarone, pacerone) AEs
- GI
- Pulmonary toxicity (lungs become fibrous)
- visual
- cardiac
- blue-grey discoloration of skin
- CNS
amiodarone (cordarone, pacerone) Interventions
- Monitor & report GI
- Baseline & periodic chest x-ray & pulmonary function tests
- Auscultate breath sounds & report changes
- Monitor changes in vision or light sensitivity
- Monitor HR & BP
- Watch cardiac rhythm constantly during IV infusion
- Monitor for wt. changes, edema, skin discoloration, CNS effects
- Oral & IV
verapamil (Calan)
Calcium channel blockers MOA
Block calcium channel blockers in the myocardium, prolongs PR interval
verapamil (Calan)
Calcium channel blockers Indications
- convert supraventricular tachycardia to regular sinus rhythm,
- slow rate of atrial fibrillation & flutter
verapamil (Calan)
Calcium channel blockers Contraindications
- Sever hypotension
- Cardiogenic shock
- Liver or kidney dysfunction
verapamil (Calan)
Calcium channel blockers AEs
- Hypotension
- Bradycardia
- HF
- Peripheral edema of feet & legs
- Lightheadedness
- Dizziness
verapamil (Calan)
Calcium channel blockers Interactions
Antihypertensive
Lithium
Grapefruit juice
verapamil (Calan)
Calcium channel blockers intervetnions
- Monitor VS & cardiac rhythm w/ IV meds. (keep patient supine for 1 hour)
- Monitor BP
- Withhold dose and notify provider for: BP lower 90 & pulse slower than 60
- Monitor for & report edema, low urine output, crackles in lungs & lightheadedness
- Oral & IV
- Give PO dose with food
unclassified antidysrhythmic
adensosine (Adenocard)
adensosine (Adenocard)
unclassified antidysrhythmic
MOA
slows conduction through AV node, very short half life (less than 10 secs!)
adensosine (Adenocard)
unclassified antidysrhythmic
Indications
convert PSVT to sinus thythm
adensosine (Adenocard)
unclassified antidysrhythmic
Contraindications
- 2nd/3rd degree heart block
- sick sinus sundrome
- Allergy
adensosine (Adenocard)
unclassified antidysrhythmic
AEs
- commonly causes asystole for a period of seconds
- all other AEs are minimal due to short half-life
adensosine (Adenocard)
unclassified antidysrhythmic
Interactions
Rare b/c of short half life
Contradictions/Cautions for ALL Antidysrhythmics
- allergy
- 2nd/3rd degree AV block
- bundle branch block
- cardiogenic shock
- sick sinus syndrome
- any other ECG changes depending on clinical judgement of cardiologist
- other antidysrhythmic drugs
AEs of ALL antidysrhythmics
- Dysrhythmias
- Hypersensitivity reactions
- N/V/D
- dizziness
- HA
- Blurred vision
- Prolongation of QT interval
Antidysrhythmic Nursing implications
- Thorough drug & medical history
- Baseline BP, HR, I/O, cardiac rhythm
- Serum K+ levels before starting
- Contraindications (specific drugs)
- Potential drug interactions
Antidysrhythmic Nursing implications
During therapy
- Monitor cardiac rhythm, HR, BP, general well-being, skin color, Temp., heart & lung sounds
- Assess plasma drug levels
- Monitor for AE & toxic effects
Antidysrhythmic Education
-Take meds as scheduled
-Do NOT skip doses or double up for missed doeses
-Do NOT crush or chew oral sustained release
Notify:
-SOB
-Edema
-Dizziness
-Syncope
-Chest pain
-GI distress
- Blurred vision
-
Antidysrhythmic Nursing Evaluations
This is what we want to see:
- Decreased BP
- Decreased edema
- Decreased fatigue
- Regular HR
- Improved regularity or rhythm
- Improved cardiac output
