Pharmacologic: beta blockers (selective)
Hypertension (alone and with other antihypertensives).
Blocks stimulation of beta-adrenergic receptor sites; selective for beta1 (myocardial) receptors in most patients. In some patients (poor metabolizers, higher blood levels may result in some beta2 [pulmonary, vascular, uterine] adrenergic) blockade. Therapeutic Effects: Lowering of blood pressure.
Adverse Reactions/Side Effects
CNS: dizziness, fatigue, headache.
PHYSICAL THERAPY IMPLICATIONS
Examination and Evaluation
Assess blood pressure periodically and compare to normal values (See Appendix F) to help document antihypertensive effects.
Assess dizziness that might affect gait, balance, and other functional activities (See Appendix C). Report balance problems and functional limitations to the physician, and caution the patient and family/caregivers to guard against falls and trauma.
Monitor excessive fatigue or weakness. Beta blockers often cause some degree of fatigue and weakness, but any sudden or severe change in muscle strength or energy levels should be reported.
Establish aerobic exercise workloads that account for the effects of beta blockers on heart rate. Some heart rate guidelines may not be appropriate because beta blockers typically decrease maximal HR by 20–30 bpm. Use other guidelines such as rating of perceived exertion (RPE, modified Borg scale) to determine exercise workloads.
To minimize orthostatic hypotension, patient should move slowly when assuming a more upright position.
Remind patients to take medication as directed to control hypertension even if they are asymptomatic.
Counsel patients about additional interventions to help control blood pressure such as regular exercise, weight loss, sodium restriction, stress reduction, moderation of alcohol consumption, and smoking cessation.
Absorption: Well absorbed following oral administration.
Metabolism and Excretion: Mostly metabolized by the liver, including the CYP2D6 enzyme system; some have antihypertensive action; minimal excretion of unchanged drug.
Half-life: Extensive metabolizers—12 hr; poor metabolizers—19 hr.
TIME/ACTION PROFILE (blood levels)
|ROUTE ||ONSET ||PEAK ||DURATION |
|PO ||unknown ||1.5–4 hr ||24 hr |
Contraindicated in: Hypersensitivity; Severe bradycardia, heart block greater than 1st degree, cardiogenic shock, decompensated heart failure or sick sinus syndrome (without pacemaker); Severe hepatic impairment (Child-Pugh >B); Bronchospastic disease; OB: Lactation.
Use Cautiously in: Coronary artery disease (rapid cessation should be avoided); Compensated congestive heart failure; Major surgery (anesthesia may augment myocardial depression); Diabetes mellitus (may mask signs of hypoglycemia); Thyrotoxicosis (may mask symptoms); Moderate hepatic impairment (↓ metabolism); Severe ...