Nonselective Beta Agonists

• These selective for beta receptors
• ↑ heart rate (+ chronotropy), ↑ contractility (+ inotropy), ↑ conductivity (+ dromotropy)
• bronchodilation
• ↑ blood flow to skeletal muscles & splanchnic bed
• relaxes uterus
• (most drugs in this class at beta-2 selective, used to manage asthma, bronchospasm, COPD)
• drugs in this class end in -terol (exception: terbutaline)

Indications

• asthma, bronchospasm, obstructive pulm conditions
• relaxation of uterus

Contraindications

• pulm HTN
• halogenated anesthesia (sensitize heart to catecholamines) 
• eclampsia, uterine hemorrhage, intrauterine death, pregnancy or lactation

Cautions

• DM, thyroid disease
• vasomotor problems
• heart disease, stroke, renal disease

Adverse Effects

• restlessness, anxiety, fear
• tachy, palpitations, angina, MI
• difficulty breathing, cough, bronchospasm
• N/V, anorexia
• may cause pulm edema, sweating, pupil dilation
• sweating, pallor

Kinetics

• Rapidly absorbed after injection
• Metabolized in the liver and excreted in the urine
• half-life usually < 1 hr

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Drugs
1. Isoproterenol (Isuprel)

• nonspecific beta agonist
• usually reserved for emergency use due to numerous AE
• given IV or injected

Indications:

• Tx shock, cardiac standstill, heart block in transplanted hearts
• prevention bronchospasm during anesthesia
• Tx bronchospams

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2. Albuterol (Proventil)

• Tx & prevention of bronchospasm
• inhaled

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Drug Interactions

• inc risk AE when combined w/ others meds in the same class

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Nursing Mgmt for Beta Specific Agonists

• baseline assessment of VS, ECG, UO
• labs: renal & hepatic function, blood glucose
• monitor for therapeutic & adverse effects