Which condition would alert the nurse of the need to use beta adrenergic blockers cautiously

General

Inhaltsverzeichnis Show

• Indications
• Pharmacokinetics (adsbygoogle = window.adsbygoogle || []).push({});
• Contraindication/Precautions
• Adverse Reactions/Side Effects
• Interactions
• Route/Dosage
• Availability (generic available)
• Potential Diagnoses
• Implementation
• Patient/Family Teaching
• Evaluation/Desired Outcomes
• What condition would alert the nurse of need to use beta adrenergic blockers cautiously?
• Which condition is an absolute contraindication to taking beta blockers?
• What health teaching should the nurse provide for the client receiving beta blockers?
• Which cholinergic symptoms of Parkinson's disease are reduced with anticholinergic drugs?

Genetic Implications:

Pronunciation:
kar-ve-di-lole

Trade Name(s)

• Coreg
• Coreg CR

Ther. Class.

antihypertensives

Pharm. Class.

beta blockers

Indications

• Hypertension.
• HF (ischemic or cardiomyopathic) with digoxin, diuretics, and ACE inhibitors.
• Left ventricular dysfunction after myocardial infarction.

Action

• Blocks stimulation of beta1 (myocardial) and beta2  (pulmonary, vascular, and uterine)-adrenergic receptor sites.
• Also has alpha1  blocking activity, which may result in orthostatic hypotension.

Therapeutic Effect(s):

• Decreased heart rate and BP.
• Improved cardiac output, slowing of the progression of HF and decreased risk of death.

Pharmacokinetics (adsbygoogle = window.adsbygoogle || []).push({});

Absorption: Well absorbed but rapidly undergoes extensive first-pass hepatic metabolism, resulting in 25–35% bioavailability. Food slows absorption.

Distribution: Unknown.

Protein Binding: 98%.

Metabolism and Excretion: Extensively metabolized (primarily by CYP2D6 and CYP2C9; the CYP2D6 enzyme system exhibits genetic polymorphism);  ~7% of population may be poor metabolizers and may have significantly ↑ carvedilol concentrations and an ↑ risk of adverse effects); excreted in feces via bile, <2% excreted unchanged in urine.

Half-life: 7–10 hr.

TIME/ACTION PROFILE (cardiovascular effects)

Contraindication/Precautions

Contraindicated in:

• History of serious hypersensitivity reaction (Stevens-Johnson syndrome, angioedema, anaphylaxis);
• Pulmonary edema;
• Cardiogenic shock;
• Bradycardia, heart block, or sick sinus syndrome (unless a pacemaker is in place);
• Decompensated HF requiring IV inotropic agents (wean before starting carvedilol);
• Severe hepatic impairment;
• Asthma or other bronchospastic disorders.

Use Cautiously in:

• HF (condition may deteriorate during initial therapy);
• Diabetes mellitus (may mask signs of hypoglycemia);
• Thyrotoxicosis (may mask symptoms);
• Peripheral vascular disease;
• History of severe allergic reactions (intensity of reactions may be ↑);
• Patients undergoing cataract surgery (↑ risk of intraoperative floppy iris syndrome);
• OB:  Crosses placenta and may cause fetal/neonatal bradycardia, hypotension, hypoglycemia, or respiratory depression;
•  Lactation:  Use while breast feeding only if potential maternal benefit justifies potential risk to infant;
• Pedi:   Safety and effectiveness not established;
• Geri:  ↑ sensitivity to beta blockers; initial dose ↓ recommended.

Adverse Reactions/Side Effects

CV: BRADYCARDIA, HF, PULMONARY EDEMA

Derm: STEVENS-JOHNSON SYNDROME, TOXIC EPIDERMAL NECROLYSIS, itching, rashes, urticaria

EENT: blurred vision, dry eyes, intraoperative floppy iris syndrome, nasal stuffiness

Endo: hyperglycemia, hypoglycemia

GI: diarrhea, constipation, nausea

GU: erectile dysfunction, ↓ libido

MS: arthralgia, back pain, muscle cramps

Neuro: paresthesia, dizziness, fatigue, weakness, anxiety, depression, drowsiness, insomnia, memory loss, mental status changes, nervousness, nightmares

Resp: bronchospasm, wheezing

Misc: HYPERSENSITIVITY REACTIONS (including anaphylaxis and angioedema), drug-induced lupus syndrome

* CAPITALS indicate life-threatening.
Underline indicate most frequent.

Interactions

Drug-Drug

•  General anesthetics,  IV phenytoin,  diltiazem, and  verapamil  may cause ↑ myocardial depression.
• ↑ risk of bradycardia with  digoxin.
•  Amiodarone  or  fluconazole  may ↑ levels.
• ↑ hypotension may occur with other  antihypertensives, acute ingestion of  alcohol, or  nitrates.
• Concurrent use with  clonidine  ↑ hypotension and bradycardia.
• May ↑ withdrawal phenomenon from  clonidine  (discontinue carvedilol first).
• Concurrent administration of  thyroid preparations  may ↓ effectiveness.
• May alter the effectiveness of  insulins  or  oral hypoglycemic agents  (dose adjustments may be necessary).
• May ↓ effectiveness of  theophylline.
• May ↓ beneficial beta1 -cardiovascular effects of  dopamine  or  dobutamine.
• Use cautiously within 14 days of  MAO inhibitor  therapy (may result in hypotension/bradycardia).
•  Cimetidine  may ↑ toxicity from carvedilol.
• Concurrent  NSAIDs  may ↓ antihypertensive action.
• Effectiveness may be ↓ by  rifampin.
• May ↑ serum  digoxin  levels.
• May ↑ blood levels of  cyclosporine  (monitor blood levels).

Route/Dosage

PO (Adults): Hypertension– 6.25 mg twice daily, may be ↑ every 7–14 days up to 25 mg twice daily  or extended-release– 20 mg once daily, dose may be doubled every 7–14 days up to 80 mg once daily;  HF– 3.125 mg twice daily for 2 wk; may be ↑ to 6.25 mg twice daily. Dose may be doubled every 2 wk as tolerated (not to exceed 25 mg twice daily in patients <85 kg or 50 mg twice daily in patients >85 kg)  or extended-release– 10 mg once daily, dose may be doubled every 2 wk as tolerated up to 80 mg once daily;  Left ventricular dysfunction after MI– 6.25 mg twice daily, ↑ after 3–10 days to 12.5 twice daily then to target dose of 25 mg twice daily; some patients may require lower initial doses and slower titration  or extended-release– 20 mg once daily, dose may be doubled every 3–10 days up to 80 mg once daily.

Availability (generic available)

Extended-release capsules: 10 mg, 20 mg, 40 mg, 80 mg

Cost: all strengths $175.36/30

Tablets: 3.125 mg, 6.25 mg, 12.5 mg, 25 mg

Cost:

Generic: All strengths $7.18/100

Assessment

• Monitor BP and pulse frequently during dose adjustment period and periodically during therapy. Assess for orthostatic hypotension when assisting patient up from supine position. If heart rate decreases below 55 beats/min, decrease dose.
• Monitor intake and output ratios and daily weight. Assess patient routinely for evidence of fluid overload (peripheral edema, dyspnea, rales/crackles, fatigue, weight gain, jugular venous distention). Patients may experience worsening of symptoms during initiation of therapy for HF.
• Hypertension: Check frequency of refills to determine adherence.

Lab Test Considerations:

May cause ↑ BUN, serum lipoprotein, potassium, triglyceride, and uric acid levels.

• May cause ↑ ANA titers.
• May cause ↑ in blood glucose levels.

Toxicity and Overdose:

Monitor patients receiving beta blockers for signs of overdose (bradycardia, severe dizziness or fainting, severe drowsiness, dyspnea, bluish fingernails or palms, seizures). Notify health care professional immediately if these signs occur.

Potential Diagnoses

• Decreased cardiac output (Side Effects) 
• Noncompliance (Patient/Family/Teaching) 

Implementation

• Do not confuse carvedilol with captopril.

  • Discontinuation of concurrent clonidine should be gradual, with carvedilol discontinued first over 1–2 wk with limitation of physical activity; then, after several days, discontinue clonidine.
• PO Take apical pulse before administering. If <50 bpm or if arrhythmia occurs, withhold medication and notify health care professional.
  • Administer with food to minimize orthostatic hypotension.
  • Administer extended-release capsules in the morning. Swallow whole; do not crush or chew. Extended-release capsules may be opened and sprinkled on cold applesauce and taken immediately; do not store mixture.
  • To convert from immediate-release to extended-release product, doses of 3.125 mg twice daily can be converted to 10 mg daily; doses of 6.25 mg twice daily can be converted to 20 mg daily; doses of 12.5 mg twice daily can be converted to 40 mg daily; and doses of 25 mg twice daily can be converted to 80 mg daily.

Patient/Family Teaching

• Instruct patient to take medication as directed, at the same time each day, even if feeling well. Do not skip or double up on missed doses. Take missed doses as soon as possible up to 4 hr before next dose. Abrupt withdrawal may precipitate life-threatening arrhythmias, hypertension, or myocardial ischemia. Discontinue carvedilol slowly over 1–2 wk. Advise patient to read  Patient Information  before starting therapy and with each Rx refill in case of changes.
• Advise patient to make sure enough medication is available for weekends, holidays, and vacations. A written prescription may be kept in wallet in case of emergency.
• Teach patient and family how to check pulse and BP. Instruct them to check pulse daily and BP biweekly. Advise patient to hold dose and contact health care professional if pulse is <50 bpm or BP changes significantly.
• May cause drowsiness or dizziness. Caution patients to avoid driving or other activities that require alertness until response to the drug is known.
• Advise patient to change positions slowly to minimize orthostatic hypotension, especially during initiation of therapy or when dose is increased.
• Caution patient that this medication may increase sensitivity to cold.
• Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult health care professional before taking other Rx, OTC, or herbal products, especially cold preparations, concurrently with this medication.
• Advise patients with diabetes to closely monitor blood glucose, especially if weakness, malaise, irritability, or fatigue occurs. Medication may mask some signs of hypoglycemia, but dizziness and sweating may still occur.
• Advise patient to notify health care professional if slow pulse, difficulty breathing, wheezing, cold hands and feet, dizziness, confusion, depression, rash, fever, sore throat, unusual bleeding, or bruising occurs.
• Instruct patient to inform health care professional of medication regimen before treatment or surgery.
• Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected, or if breast feeding. If carvedilol is taken during third trimester, monitor newborn for symptoms of hypotension, bradycardia, hypoglycemia, and respiratory depression and manage accordingly.
• Advise patient to carry identification describing disease process and medication regimen at all times.
• Hypertension: Reinforce the need to continue additional therapies for hypertension (weight loss, sodium restriction, stress reduction, regular exercise, moderation of alcohol consumption, and smoking cessation). Medication controls but does not cure hypertension.

Evaluation/Desired Outcomes

• Decrease in BP without appearance of detrimental side effects.
• Decrease in severity of HF.