Adrenergic-Blocking Drugs Flashcards
Adrenergic Blockers
- binds to adrenergic receptors but inhibit or block stimulation of the sympathetic nervous system
- Have the opposite effect of adrenergic drugs
- Inhibit or Lyse sympathetic stimulation
Other names for adrenergic blockers?
Adrenergic antagonists sympatholytics alpha blockers beta blockers alpha-beta blockers
MOA and Drug effects
- cause both arterial and venous dilation, reducing peripheral vascular resistance and BP
- used to treat hypertension
- Effect on receptors on prostate gland and bladder decreases resistance to urinary outflow, thus reducing urinary obstruction and relieving effects of benign prostatic hyperplasia
Indications for Alpha Blockers
control and prevent hypertension in patients with phenochromocytoma
-Raynauds disease, acrocyanosis, and frostbite
Phentolamine
- quickly reverses the potent vasoconstrictive effects of extravasated vasopressors such as norepinephrine or epinephrine
- restores blood flow and prevents tissue necrosis
Adverse effects: Alpha Blockers
Cardiovascular
palpitations, orthostatic hypotension, tachycardia, edema, chest pain
Adverse effects: Alpha Blockers
CNS
dizziness, headache, anxiety, depression, weakness, numbness, fatigue
Adverse effects: Alpha Blockers
GI
nausea, vomiting, diarrhea, constipation, abdominal pain
Adverse effects: Alpha Blockers
Other
incontinence, dry mouth, pharyngitis
Tamsulosin (Flomax)
- alpha blocker used primarily to treat BPH; is exclusively indicated for male patients however, can be used in female patients with kidney stones
- Contraindications: known drug allergy and concurrent use of erectile dysfunction drugs such as sildenafil
- Adverse effects: headache, abnormal ejaculation, rhinitis, and others
Beta Blockers
- block stimulation of beta receptors in the SNS
- compete with norepinephrine and epinephrine
- Can be selective or nonselective
- cardioselective beta blockers or beta1-blocking drugs
- Nonselective beta blockers block both beta1 and beta2 receptors
- Beta2 receptors are located primarily on the smooth muscles of the bronchioles and blood vessels
Beta Blockers MAO
Cardioselective beta blockers (beta1)
- reduce SNS stimulation of the heart
- Decrease heart rate
- Prolong SA node recovery
- Slow conduction rate through the AV node
- Decrease myocardial contractility, thus reducing myocardial oxygen demand
Beta Blockers MAO
Nonselective beta blockers (beta1 and beta2)
- cause same effects on heart as cardioselective beta blockers
- constrict bronchioles, resulting in narrowing of airways and shortness of breath
- produce vasoconstriction of blood vessels
Indications to use Beta Blockers
-Angina-Decreases demand for myocardial oxygen
-Cardioprotective
-dysrhythmias
-Migraine
antihypertensive
-heart failure
-glaucoma
What does cardioprotective mean?
inhibits stimulation from circulating catecholamines
-used in patients who have had a MI
Adverse Effects: Beta Blockers
Blood
agranulocytosis, thrombocytopenia
Adverse Effects: Beta Blockers
Cardiovascular
AV block, bradycardia, heart failure
Adverse Effects: Beta Blockers
CNS
Dizziness, depression, unusual dreams, drowsiness
Adverse Effects: Beta Blockers
GI
Nausea, vomiting, diarrhea, constipation
Adverse Effects: Beta Blockers
other
impotence, alopecia, wheezing, bronchospasm, dry mouth
Toxicity and Management of Overdose
- symptomatic and supportive care
- Atropine for bradycardia
- cardiac pacing
- vasopressors for severe hypotension
- Hemodialysis to enhance elimination in severe overdoses
what drugs might interfere with Adrenergic-Blocking Drugs?
antacids antimuscarinics or anticholinergics diuretics and cardivascular drugs neuromuscular blocking drugs oral hypoglycemic drugs
Adrenergic-Blocking Nursing Implication
These medications should never be stopped abruptly
- Inform patients to report constipation or the development of urinary hesitancy or bladder distention
- possibility of postural hypotension
- avoid caffeine
- avoid alcohol
- notify is you experience palpitations, dyspnea, N/V
Beta-Blocking Drug Nursing implications
- Rebound hypertension or chest pain may occur if this medication is discontinued abruptly
- May notice a decrease in tolerance for exercise and notify if this problem occur
- Report weight gain of more than 2 lb in 1 day or 5 lb in 1 week, edema of feet or ankles, SOA, excessive fatigue or weakness, syncope or dizziness
