McKenna's Pharmacology for Nursing, 2e

484

P A R T 5  Drugs acting on the autonomic nervous system

Care considerations for people receiving beta 1 -selective adrenergic blocking agents Assessment: History and examination allergies to any drug or any components of the drug to avoid hypersensitivity reactions ; bradycardia or heart blocks, shock or HF, which could be exacerbated by the cardiac-suppressing effects of these drugs ; diabetes, thyroid disease or COPD to reduce risk of adverse effects on these conditions due to sympathetic blockade ; and current status of pregnancy or breastfeeding because of the potential effects on the fetus or neonate. ■ ■ Perform a physical assessment to establish baseline status before beginning therapy to determine the effectiveness of therapy and evaluate for any potential adverse effects. ■ ■ Assess neurological status, including level of orientation and sensation, to evaluate for CNS effects. ■ ■ Monitor cardiac status, including pulse, blood pressure, and heart rate, to identify changes , and obtain an ECG as ordered to evaluate for changes in heart rate or rhythm . ■ ■ Assess pulmonary status, including respirations, and auscultate lungs for adventitious sounds to monitor respiratory status. ■ ■ Examine the abdomen and auscultate bowel sounds to evaluate GI effects. ■ ■ Monitor urine output to monitor the effectiveness of cardiac output and any changes in renal perfusion. including electrolyte levels, to monitor for risk of arrhythmias , and renal and hepatic function studies, to determine the need for possible dose adjustment. ■ ■ Assess for contraindications or cautions: known ■ ■ Monitor the results of laboratory tests, ■ ■ Do not stop these drugs abruptly after chronic therapy, but taper gradually over 2 weeks to prevent the possibility of severe reactions. Long-term use of these drugs can sensitise the myocardium to catecholamines and severe reactions could occur. ■ ■ Consult with the doctor about discontinuing these drugs before surgery because withdrawal of the drug before surgery when the person has been maintained on the drug is controversial. ■ ■ Give oral forms of metoprolol with food to facilitate absorption. Implementation with rationale

■ ■ Continuously monitor any individual receiving an intravenous form of these drugs to detect severe reactions to sympathetic blockade and to ensure rapid response if these reactions occur. ■ ■ Arrange for supportive care and comfort measures, including rest, environmental control and other measures, to relieve CNS effects ; safety measures if CNS effects occur, to protect the person from injury ; small, frequent meals and mouth care to relieve the discomfort of GI effects ; and an activity program and daily energy management ideas to help to deal with activity intolerance. ■ ■ Offer support and encouragement to help the person deal with the drug regimen. ■ ■ Provide thorough teaching, including drug name, dosage and schedule for administration; use of drug with food or meals if appropriate; technique for ophthalmic administration if indicated; potential adverse effects, measures to avoid drug- related problems, and warning signs of problems; safety measures such as changing position slowly and avoiding driving or operating hazardous machinery; and energy conservation measures as appropriate. Evaluation ■ ■ Monitor response to the drug (lowered blood pressure, fewer anginal episodes, lowered intraocular pressure). ■ ■ Monitor for adverse effects (GI upset, CNS changes, cardiovascular effects, loss of libido and impotence, potential respiratory effects). ■ ■ Evaluate the effectiveness of the teaching plan (person can name drug, dosage, adverse effects to watch for and specific measures to avoid them). ■ ■ Monitor the effectiveness of comfort measures and compliance with the regimen.

KEY POINTS

■■ Beta 1

-selective adrenergic blocking agents do not

block the beta 2 -receptors that are responsible for bronchodilation and therefore are preferred in individuals with respiratory problems. ■■ Beta 1 -selective adrenergic blocking agents are used to treat hypertension and angina in extended-release forms and to treat HF. ■■ All of the adrenergic blocking drugs must be tapered when they are discontinued after long-term use. The blocking of the receptor sites makes them hypersensitive to catecholamines, and extreme hypertension, angina, MI or stroke could occur.