Chapter 22 - Antihypertensive Drugs Flashcards
What is hypertension?
High Blood Pressure
Older than 60 years old: Systolic pressure greater than 150 and a diastolic greater than 90 mm of Hg
Younger or with chronic kidney disease or diabetes: Systolic greater than 140 and Diastolic greater than 90
What is blood pressure?
Cardiac Output x Systemic Vascular Resistance
Hypertension is a risk factor for which two diseases?
Coronary Artery Disease (CAD) Cardiovascular Disease (CVD)
What is the JNC - 8?
Eighth Report of the Joint National Committee on Prevention, Detection, Education, and Treatment of High Blood Pressure
Important for determining what blood pressure medication to use
What is Primary Hypertension?
- Unknown cause
- Also referred to as essential, idiopathic, or primary hypertension
- 90% of all cases
What is Secondary Hypertension?
- Known cause
- 10% of all cases
- Adrenal tumor, thyroid disease, parathyroid disease, preeclampsia (acute HTN during pregnancy), renal disease, sleep apnea
What are Centrally Acting Adrenergic drugs?
Action:
- Stimulate alpha-2 adrenergic receptors in the brain - (decrease norepinephrine production)
- reduce renin activity
Meds: Clonidine and Methyldopa
Effect: Decreased BP
What are Peripherally Acting Alpha-1 Blockers?
Action:
- Dilate arteries and veins
- Used for the urinary system (benign prostatic hyperplasia - BPH - shrink it)
- Increase urinary flow rates and decrease outflow obstruction by preventing smooth muscle contraction in the bladder neck and urethra
Meds: Doxazosin, Prazosin, Terazosin
(Doxins Practice Terribly)
Effect: Decreased BP
What are Beta Blockers?
Action:
- Reduction of the heart rate through beta receptor blockade
- Long term use causes reduced peripheral vascular resistance
- Used for Angina and Conduction problems
- Decreased production of renin
Drugs: Propanolol, Metoprolol, Atenolol
(Propane Met Attention)
Effect: Decreased BP
What are some adverse effects of Adrenergic Drugs?
-Risk of Orthostatic Hypotension
-First Dose Syncope - hypotensive effect that is severe enough to cause patient to loose consciousness
(patient should change positions slowly to give blood volume time to redistribute)
-Bradycardia with Tachycardia Reflex
-Dry Mouth
-Drowsiness and sedation
-Constipation
-Depression
-Edema
-Headaches
-Sleep Distrubances
-Nausea
-Rash
-Rebound HTN
-Sexual Dysfunction
What happens when mixing adrenergic drugs with alcohol, benzodiazapines, and opioids?
CNS Depression
Adrenergic drugs are used as first line defense T or F?
False - high incidence of unwanted effects, older drugs, used as adjunct meds (added onto new meds), used in conjunction with diuretics
Along with decreasing blood pressure what is Clonidine used for?
Opioid Withdrawal
- Oral or topical patch
- Do not stop abruptly (rebound HTN)
Tamulosin controls blood pressure T or F?
False - Alpha blocker used to control BPH
What is Carvediol?
Dual-Action Alpha and Beta Receptor Blocker
- well tolerated
- Used for HTN and mild to moderate HF in conjunction with digoxin, diuretics, and ACE inhibitors
- Contraindications: known drug allergy, cardiogenic shock, severe bradycardia or HF, bronchospastic conditions such as asthma, conduction problems
What is Bystolic (Nebivolol)?
- Beta blocker
- Used for for HTN and HF
- Blocks Beta Receptors and produces vasodilation (resulting in decrease o systemic vascular resistance)
- less chance of sexual dysfunction
- tapered over 1 to 2 weeks
What are ACE inhibitors?
Angiotensin Converting Enzyme Inhibitors (ACE Inhibitors)
Action:
-Inhibit Angiotensin Converting Enzyme (responsible for converting angiotensin I to angiotensin II - these are potent vasoconstrictors that induce aldosterone secretion by the adrenal gland
Drugs: End in “pril” - Captopril, Benazepril, Enalapril
Effect:
- Decrease SVR (measure of afterload and preload) and therefore decrease BP
- Diuresis: Decreases blood volume and return to the heart
- Decreases preload (left ventricular end diastolic volume)
- Decreases work required of the heart
- Used to prevent complications after MI
- Ventricular remodeling - left ventricular hypertrophy - protective
- Decrease mortality and morbidity in patients with HF (drug of choice for patients with HF)
What are the renal protective effects of ACE Inhibitors?
- Reduces glomerular filtration rates
- Cardiovascular drug of choice for patients with diabetes
- Reduce proteinura
- Prevents progression of diabetic neuropathy
What are some adverse effects of ACE inhibitors?
-Most common: dry, nonproductive cough***
(will stop once ACE inhibitor is stopped)
-Angiodema - rare, fatal, starts shortly after starting med (tissue swelling under the skin), that causes difficulty breathing b/c of pressure on airway, periorbital edema (around eye)
-headache
-mood changes
-impaired taste
-possible hyperkalemia
Which ACE inhibitor is used to prevent ventricular remodeling and HF after MI and has a short half life?
Captopril (Capoten) - Leonardo Decaprio has a short life
-must be administered multiple times a day
What is Enalapril (Vasotec)?
- Only Ace Inhibitor available in both oral and parenteral forms (Nala needs a parent)
- Does not require cardiac monitoring
- Prodrug
- Reduces HF
What is an ARB?
Angiotensin II Receptor Blocker
Action:
-Block the binding of Angiotensin II to the type I Angiotensin II receptors in these tissues
-Block vasoconstriction and the secretion of aldosterone
-Affect primarily smooth muscle and the adrenal gland
Meds: End in -sartan ex. Losartan (Cozaar), Eprosartan (Teveten)
Effects:
- Just as effective as ACE in treating HTN
- Do not cause cough
- Evidence that ARBS are better tolerated and cause less mortality after MI than ACE
- Not clear if as effective in treating HF or protecting kidneys in diabetes - used as adjunct drug
- May be used alone or with other drugs such as dieuretics
What are some adverse effects or ARBs?
- Chest pain
- Fatigue
- Hypoglycemia
- Diarrhea
- UTI
- Anemia
- Weakness
- Hyperkalemia and cough less likely to occur in ARBs
What is Losartan (Cozaar)?
- An ARB used for patients with HTN and HF
- Used with caution in pts with renal or hepatic dysfunction and renal artery stenosis
- Not safe for breastfeeding and pregnant women
What are Calcium Channel Blockers?
Action:
- Relaxation of smooth muscle by blocking binding of calcium to receptors
- Used for HTN and Angina
- used in chronic migraine sufferers
- CCB - decrease peripheral smooth muscle allowing dilation and blood flow to patients hands (Raynaud’s disease)
Meds: Amlodipine (Norvasc)
(Diplo needs more calcium)
Effects: Decrease in smooth muscle tone, BP, SVR, and stroke volume
What are Diuretics?
Action:
- Decrease plasma and ECF volume
- First line antihypertensives for the treatment of HTN
Drugs: Thiazide Diuretics most commonly used for HTN
Effects:
- Decreased preload (stretch during filling of ventricles)
- Decreased CO
- Decreased total peripheral vascular resistance
- Decreased overall workload of heart and BP
What are vasodilators?
Action:
- Directly relax arteriolar or venous smooth muscle
- Treats HTN
- Used in combination with other drugs
Meds: Sodium Nitroprusside (Nitropress), Hydrazine (Apresoline), Minoxidil
Effects:
- Decreased SVR
- Decreased afterload
- Peripheral vasodilation
What vasodilators are used in emergency situations?
Sodium Nitroprusside and IV Diazoxide
What are some adverse effects of Hydrazine?
Dizziness, headache, anxiety, tachycardia, edema, dyspnea, nausea, vomiting, diarrhea, hepatitis, Vitamin B6 deficiency and rash
What are some adverse effects of Minoxidil?
T-wave electrocardiographic changes, pericardial effusion or tamponade, angina, breast tenderness, rash and thrombocytopenia (low platelet level)
What are some adverse effects of Sodium Nitroprusside?
Bradycardia, decreased platelet aggregation, rash, hypothyroidism, hypotension, methemoglobinemia, cyanide toxicity
What is pulmonary hypertension?
-affects the arteries in your lungs
-makes it harder for blood flow to occur to your lungs because of changes in pulmonary arterioles
(lower left ventricle has to work harder to pump blood through the lungs - causing heart muscle to weaken)
Symptoms: SOB, fatigue, dizziness, chest pain or pressure, swelling in the ankles, cyanosis to lips, and heart palpitations
Meds different than HTN
What is Sildenafil?
Viagra
- used for ED and treating high BP
- important to ask if taking vasodilator because can bottom out BP
Before beginning therapy what is the most important step?
- health history and head to toe examination
- assess for contraindications to specific antihypertensive drugs
Why should oral forms of meds be given with meals?
Absorption is more effective and gradual
Along with medications for therapy what also is important?
- diet (avoid high sodium foods)
- stress level
- weight
- alcohol intake
- encourage exercise
What two lab values should be monitored with ACE inhibitors?
Creatinine - sign of renal impairment
Potassium - can cause hyperkalemia
