HTN Drugs Flashcards
5 Classes for HTN Drugs
1) Diuretics
2) Adrenergic agents
3) CCBs
4) RAAS drugs
5) Vasodilators
What are the 2 Actions of Diuretics?
- Decrease BLOOD VOLUME by urinary excretion of water and electrolytes
- Decrease arterial resistance
What are the 3 Classes of Loop Diuretics?
Indicate the Prototype for each:
- Loop: Furosemide (Lasix)
- Thiazide: Hydrochlorothiazide (HCTZ)
- K+-sparing: Spironolactone (Aldactone)
Can we use Diuretics for both HTN & HF?
YES!
HTN: ↓ Blood volume (arterial resistance)
HF: ↓ Blood volume (Preload) & Workload on heart
- only treats SYMPTOMS
- 1st line therapy for acute pulmonary edema
- usually used in combo w/ other HF drugs
Furosemide (Lasix) MOA & Uses:
- DECREASES BLOOD VOLUME
Inhibits reabsorption of Na & Cl at the loop of Henle
Uses:
- Mainly used for HTN uncontrolled by other diuretics, or in pts with Kidney disease
- HF Sxs (pulmonary edema)
Furosemide (Lasix) Routes:
Indicate Onset & Duration
- PO
onset: 1 hr
Duration: 8 hrs - IV
Onset: 5 min
Duration: 2 hrs
Furosemide (Lasix) Side Effects:
- Electrolyte imbalances (Na, Cl, K+)
- HYPOkalemia - Dehydration
- Orthostatic hypotension + hypotension
- Ototoxicity
- Gout exacerbation
- Increases uric acid
Furosemide (Lasix) Contraindications:
- PREGNANCY!
- Digoxin & lithium
- Risk for toxicity!
Hydrochlorothiazide (HCTZ) MOA & Uses:
- DECREASES BLOOD VOLUME (fast)
Acts on DCT resulting in excretion of H20, Na, and K+ - Decreases Arterial resistance (slow/over time)
Uses:
- MOST WIDELY USED diuretic for HTN
- HF
Hydrochlorothiazide (HCTZ) Routes:
Indicate Onset, Peak, & Duration
- PO
Onset: 2 hrs
Peak: 4-6 hrs
Duration: 12 hrs
Hydrochlorothiazide (HCTZ) Side Effects:
- electrolyte imbalances (K+, Na, Cl)
- HYPOkalemia - Dehydration, hypovolemia (FVD)
- Hyperglycemia (DM)
- inhibits insulin release - Gout exacerbation
- Increases uric acid
Hydrochlorothiazide (HCTZ) Contraindications:
- Digoxin & lithium
- Risk for toxicity!
Spironolactone (Aldactone) MOA & Uses:
- DECREASES BLOOD VOLUME
Competes with & thus Blocks Aldosterone at receptors in the DCT, resulting in loss of H2O (K+ remains)
Uses:
- HTN
- used in combo with Loop/Thiazide diuretics to decrease K+ loss - HF: Edema Sxs; Blocks negative effects of Aldosterone (cardiac remodeling)
- NOT used in severe HF (reduces mortality)
Spironolactone (Aldactone) Routes:
Indicate Onset
- PO
Onset: up to 48 hrs
Spironolactone (Aldactone) Side Effects:
- HYPERkalemia risk
- Endocrine effects
- gynecomastia, voice deepening, hirsutism
Spironolactone (Aldactone) Contraindictions:
- Concurrent use with other RAAS drugs (ACE, ARBs, DRIs, ARNI)
- K+ Supplements
- increase HYPERkalemia risk & cardiac dysrhythmias
Nursing Considerations for Diuretics:
- Administer early in the day
- don’t want pts up all night tinkling - Obtain K+ levels before administration
- Monitor hydration status
- Daily weights
- I/O measurements - Teach about foods high in K+ for diuretics that cause HYPOkalemia (Loop/Thiazide)
How does the dosing of diuretics differ with HTN and HF? How do we determine the dosing in HF?
Diuretic Dosing in HF is based on DAILY WEIGHTS
Patients may be given a “Sliding scale” based on daily weight measurements
What are the 4 Classes of Adrenergic Agents used for HTN?
Identify the Prototype for each class:
- Alpha2 AGONIST: Clonidine (Catapres)
- Alpha1 Blocker: Prazosin (Minipress) “osins”
- Beta-Blocker: Metoprolol (Lopressor, Topol XL) “lols”
- Alpha/Beta Blocker: Carvedilol (Coreg)
Clonidine (Catapres) Uses & MOA:
Uses:
- HTN: SEVERE HTN MANAGEMENT (PRN orders)
- Off-label uses: Pain management, ADHD
MOA:
Alpha2 AGONIST; Sympathomimetic/Adrenergic Agonist
Blocks the SNS action on arterioles and veins resulting in VASODILATION (↓ CO –> ↓ BP)
Centrally-acting:
Acts on the brainstem to decrease the Sympathetic outflow, thereby decreasing SNS stimulation on the heart & blood vessels (decreases NE production at presynaptic terminals)
Clonidine (Catapres) Routes:
- PO
- Patch (transdermal)
- q7 days
Clonidine (Catapres) Side Effects:
- Dry mouth
- Sedation/Drowsiness
- Rebound HTN
Clonidine (Catapres) Nursing Considerations:
- Instruct pt to NOT STOP USE ABRUPTLY
- risk for rebound HTN - Assess pt for Abuse potential
- Potential for abuse in pts using opioids, benzos, cocaine, etc.
Prazosin (Minipress) Uses & MOA
Uses:
- HTN
- NOT 1st line therapy
- NOT as a monotherapy - BPH
MOA:
Alpha1 AGONIST; Antiadrenergic
Blocks the SNS action on arterioles and veins resulting in vasodilation
Also, causes relaxation of smooth muscles in the bladder neck and prostatic capsule (BPH)
Prazosin (Minipress) Routes
PO
Prazosin (Minipress) Side Effects
- Nasal congestion
- Orthostatic hypotension
- 1st dose phenomenon - Reflex Tachycardia
- Inhibits ejaculation
Prazosin (Minipress) Nursing Considerations:
- Administer at bedtime to decrease fall risk
OR - Instruct pt not to get up for 3 hrs after 1st dose
Metoprolol (Lopressor, Topol XL) Uses & MOA:
Uses:
- HTN
- HF
- usually in combo with an ACE &/or Diuretic
MOA: Beta1 Blocker (Cardioselective); Antiadrenergic Agent
Heart: ↓ HR, Contractility, & AV Conductivity resulting in ↓ Cardiac output
Kidney: ↓ release of renin resulting in ↓ PVR over time