U01.16.053 β2-agonists

β2-agonists are a class of medications primarily used to manage asthma and other respiratory conditions. These drugs work by relaxing the bronchial smooth muscles, which helps alleviate symptoms such as wheezing, coughing, and shortness of breath.

Classification and Usage

1. Short-acting β2-Agonists (SABAs)

Albuterol
- Mechanism of Action: Relaxes bronchial smooth muscle.
- Clinical Use: Primarily used for acute exacerbations of asthma.
- Adverse Effects: May cause tremors and arrhythmias.

2. Long-Acting β2-Agonists (LABAs)

Salmeterol
- Mechanism of Action: Provides prolonged bronchodilation by relaxing bronchial smooth muscle.
- Clinical Use: Used for long-term prophylaxis of asthma.
- Adverse Effects: May cause tremors and arrhythmias.
Formoterol
- Mechanism of Action: Similar to Salmeterol, with rapid onset and prolonged action.
- Clinical Use: Also used for long-term asthma control.
- Adverse Effects: Similar to Salmeterol, it can cause tremors and arrhythmias.

Key Points to Remember

Acute vs. Chronic Management: SABAs like Albuterol are preferred for immediate relief during an asthma attack, while LABAs such as Salmeterol and Formoterol are used for long-term control.
Adverse Effects: Both SABAs and LABAs can cause tremors and arrhythmias, so they should be used with caution, especially in patients with cardiovascular conditions.
Combination Therapy: LABAs are often used in combination with inhaled corticosteroids for better management of chronic asthma.

Summary Table

Drug	Type	Usage	Adverse Effects
Albuterol	Short-Acting	Acute exacerbations of asthma	Tremor, arrhythmia
Salmeterol	Long-Acting	Prophylaxis of asthma	Tremor, arrhythmia
Formoterol	Long-Acting	Prophylaxis of asthma	Tremor, arrhythmia

β2-agonists

Bibliography

National Heart, Lung, and Blood Institute. (2020). Asthma Care Quick Reference: Diagnosing and Managing Asthma. Retrieved from NHLBI Website.
Global Initiative for Asthma (GINA). (2023). Global Strategy for Asthma Management and Prevention. Available at GINA Asthma Guidelines.

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