2️⃣ Beta2-Adrenergic Agonists (Adrenergics)

What is the prototype beta2-adrenergic agonist?

Albuterol

What is the pharmacologic class of albuterol?

Beta2-adrenergic agonist

What is the therapeutic class of albuterol?

Bronchodilator

What is the primary action of albuterol?

Stimulates beta2 receptors → bronchodilation

What enzyme is stimulated by beta2 receptors?

Adenylyl cyclase

What does increased cyclic AMP cause?

Relaxation of bronchial smooth muscle

Is albuterol short-acting or long-acting?

Short-acting (SABA)

What type of inhaler is albuterol?

Rescue inhaler

What is the onset of action for inhaled albuterol?

5–15 minutes

What is the duration of action for inhaled albuterol?

3–6 hours

How is albuterol metabolized?

Liver

Is albuterol safe in pregnancy?

Yes, preferred SABA during pregnancy

Does albuterol cross the placenta?

Yes

Is albuterol compatible with breastfeeding?

Generally considered safe

What are indications for albuterol?

Bronchospasm, exercise-induced asthma, acute asthma symptoms

What is the oral onset of albuterol?

15–30 minutes

What is the peak action for oral albuterol?

2–3 hours

What is the max oral dose of albuterol?

32 mg/day

What are common adverse effects of albuterol?

Muscle tremor, tachycardia, palpitations, nervousness

What are severe adverse effects of albuterol?

Dysrhythmias, cardiac arrest

What CNS symptoms may occur with albuterol?

Agitation, insomnia, seizures, anxiety

What is a contraindication to albuterol?

Hypersensitivity, tachydysrhythmias, severe CAD

Caution should be used in patients with what conditions?

Hypertension, hyperthyroidism, diabetes, seizure disorders

What drugs block albuterol’s effects?

Beta-blockers

What drugs enhance albuterol’s effects?

Thyroid hormones, theophylline, MAOIs, caffeine

How should albuterol inhalers be used with other inhalers?

Use albuterol first, then wait 5+ minutes

Why use albuterol first?

Opens airways → improves absorption of other inhaled drugs

What happens with overuse of albuterol?

Receptors become less responsive → tolerance develops

Does tolerance occur with long-acting beta2-agonists?

No

How should inhalers be spaced apart?

3–5 minutes between puffs

What are therapeutic effects of albuterol?

↓ Dyspnea, ↓ wheezing, improved RR, improved oxygenation

What adverse signs should nurse monitor for?

Tachycardia, dysrhythmia, restlessness, insomnia

Why must patients keep albuterol supply available?

For emergency self-treatment

Why is albuterol given in status asthmaticus?

To relieve acute bronchospasm

How often may albuterol be repeated in status?

Every 20 minutes x 3 doses, then PRN

Why monitor K+ in high-dose albuterol?

Risk of hypokalemia

What are the other short-acting beta2 agonists?

Levalbuterol, metaproterenol

What are the long-acting beta2 agonists?

Formoterol, salmeterol

Are LABAs rescue meds?

NO — maintenance only

Why must LABAs not be used alone in asthma?

↑ Risk of asthma-related death; must combine with ICS

What is the black box warning for salmeterol?

Initiating in worsening asthma may be life-threatening

What is levalbuterol used for?

Alternative SABA for bronchospasm

Why is metaproterenol less preferred?

More cardiac stimulation at higher doses

What is formoterol used for?

Maintenance, NOT acute symptoms

What is salmeterol’s onset?

~20 minutes → NOT for acute attacks

How often should LABAs be used?

Every 12 hours, no more

If breakthrough bronchospasm occurs on LABA, what should pt use?

Albuterol (SABA)

What should pts know about SABA use?

Use PRN, not scheduled

What does frequent SABA use indicate?

Poor control → needs step-up therapy

What is the role of the nurse in teaching albuterol use?

Teach correct inhaler technique, spacer use, side effect monitoring, importance of adherence