Explain the significance of vasodilator selectivity in terms of the effects on Afterload.
Afterload: The force the heart has to work against to pump
... [Show More] blood
Drugs that affect arterioles lower cardiac afterload, resulting in increased cardiac output, tissue perfusion, and lower cardiac work
Explain the significance of vasodilator selectivity in terms of the effects on Preload.
Preload: The degree of stretching the ventricular muscles does before contraction.
Drugs that dilate veins lower the force of blood that returns to the heart, which lowers ventricular filling, lowering the preload and force of ventricular contraction, cardiac work, cardiac output, and tissue perfusion
What are the principal therapeutic indications of vasodilators?
- Treats Essential HTN
- Hypersensitive crisis
- Angina Pectoris
- Heart failure
- myocardial Infarction
What are the adverse effects common to most vasodilators?
- Postural hypotension due to relaxation of the smooth muscles in veins
- Reflex Tachycardia due to dilation of arterioles or veins
- Expansion of Blood Volume
List:
The sites of action of antihypertensive drugs
The classes of drugs acting at those sites
Brainstem - alpha-2-agonist (clonidine)
Sympathetic Ganglia - adrenergic neuron blockers (reserpine)
Cardiac beta receptors - beta blockers (metoprolol)
Vascular alpha1 receptors - alpha1 blocker (prazosin)
Vascular smooth muscle - direct acting vasodilator
Renal Tubules - thiazide and related diuretics (hydrochlorothiazide)
Beta1receptors on juxtaglomerular cells - beta blocker (metoprolol)
Renin - angiogenin II receptor blocker (aliskiren)
Angiotensin converting Enzyme - ACE inhibitor (captopril)
Angiotensin II receptors - angiotensin II receptor blockers (Losartan)
Aldosterone Receptors - aldosterone antagonists (eplerenone)
What is a compelling indication of antihypertensive drugs?
Comorbid condition for which a specific class of antihypertensive drugs that have shown to improve outcomes
How do compelling indications affect the choice of drug for control of hypertension?
Patients with hypertension and compelling indications use specific antihypertensive drugs to reduce morbidity and mortality during initial therapy
What are the benefits of multidrug therapy for the treatment of hypertension?
1. increases the chances of success by being able to target multiple sites at once
2. Can be administered at lower dosages, decreasing the frequency and intensity of side effects
3. One drug can offset the adverse effects of the other
What are actions that nurses can take to improve diagnosis and treatment of hypertension in special populations?
African Americans:
- Routine monitoring of BP
- Early detection
- Lifestyle modifications
Children and Adolescents:
- Adjust dosages
- Detect early through screening
Older Adults:
- Monitor BP
- Early testing
- Look for isolated systolic hypertension
What actions can nurses take to minimize adverse effects in the treatment of hypertension?
- Tailor drug therapy to fit the needs of the patient
- If one drug causes adverse effect --> sub it out
- Enough patients to report signs and symptoms
- Low dosage first and then gradually increase them
How can nurses promote adherence to hypertension treatment?
- Patient education
- Teach Self-monitoring
- Minimize adverse effects
- Establish collaborative relationship
- Simplify the regimen
- Positive reinforcement
- Involve the family if okay with patient
- Schedule office appointments
What are the general principles for treating hypertensive emergencies?
If BP is associated with papilledema, intracranial hemorrhage, MI, acute congestive failure --> considered an emergency, need to lower BP within 1 hr
If BP isn't causing organ damage --> lower BP over 24-48 hr
How will drugs for hypertensive emergencies be administered?
Administered through IV
What is the drug of choice for treating hypertensive emergencies?
Sodium Nitroprusside: direct acting vasodilator of arterioles and veins
- IV at 0.3-3 mcg/Kg/min
- BP is monitored throughout
When is chronic hypertension treated with medication during pregnancy?
Usually before pregnancy, unless they are ACE inhibitors, ARBs, and DRIs or
If systolic BP raises up to 160 mmHg or diastolic BP raises up to 110 mmHg
What medications are used during pregnancy to treat chronic hypertension?
Methyldopa or labetalol
When is preeclampsia treated with medication?
If BP goes above 130/90 mmHg and there is proteinuria (300 mg+ in 24 hrs) that occurs after 20th week in gestation, but usually during delivery
What medications are used to treat preeclampsia?
Labetalol (20 mg IV over 2 mins)
What medications are used to prevent eclampsia?
Magnesium sulfate
What are the expected pharmacological effects of heparin (antithrombin drug)?
Heparin is a anticoagulant drug that binds to antithrombin and thrombin to form a tertiary complex or it binds to antithrombin, which binds to factor Xa.
Both suppresses Fibrin formation to reduce coagulation.
What are the therapeutic indications of heparin?
- Good for pregnant clients because it doesn't cross the placenta
- Reduces pulmonary embolism
- Reduces deep vein thrombosis
- Prevents postoperative venous thrombosis
-decreases intravascular coagulation, which reduces clots
- Reduces clots --> good for acute MI [Show Less]