From the Guidelines
Adenosine causes bronchoconstriction rather than bronchodilation, particularly in patients with asthma or other reactive airway diseases, as it activates A1 receptors in the bronchial smooth muscle, leading to contraction of these muscles and narrowing of the airways 1.
Mechanism of Action
The bronchoconstricting effect of adenosine is mediated through mast cell degranulation and release of inflammatory mediators, as well as direct effects on airway smooth muscle, making it a potential trigger for asthma exacerbations in susceptible individuals.
Clinical Implications
This property is important to recognize when adenosine is used for its other purposes, such as treating supraventricular tachycardia, as respiratory monitoring may be necessary during administration.
Key Points
- Adenosine-induced bronchoconstriction in asthmatics may depend on the state of airway mast-cell priming 1.
- Adenosine challenge may be a useful tool in the differential diagnosis of asthma and COPD in patients of all ages in whom the diagnosis is clinically uncertain 1.
- The specificity of adenosine bronchoprovocation for asthma, together with the high repeatability of this test, could be useful for epidemiological studies 1.
From the FDA Drug Label
Adenosine injection administration can cause dyspnea, bronchoconstriction, and respiratory compromise. Known or suspected bronchoconstrictive or bronchospastic lung disease (e.g., asthma) ( 4) Bronchoconstriction. Can induce dyspnea, bronchoconstriction, and respiratory compromise, especially in patients with obstructive pulmonary disease.
Adenosine causes bronchoconstriction. It should not be used in patients with bronchoconstriction or bronchospasm, such as asthma 2, 2.
From the Research
Adenosine's Effect on Airways
- Adenosine has been shown to cause bronchoconstriction in asthmatic patients, as demonstrated in a study published in 1984 3.
- The study found that inhaled adenosine was less potent than histamine in producing bronchoconstriction, but still caused significant airway constriction.
- Another study published in 2006 found that aerosolized adenosine induces bronchoconstriction in patients with asthma and chronic obstructive pulmonary disease, primarily through the release of mast cell mediators 4.
Mechanism of Adenosine-Induced Bronchoconstriction
- A study published in 2011 found that adenosine induces airways obstruction in subjects with asthma through the activation of adenosine A(1) receptors, which is mediated by the action of capsaicin-sensitive sensory nerves 5.
- Another study published in 1985 found that adenosine-induced bronchoconstriction in asthma is not primarily due to parasympathetic stimulation or adrenergic inhibition, but rather through an undefined mechanism 6.
Clinical Implications
- Adenosine has been implicated in promoting inflammation and airway remodeling in chronic lung disease, making it an attractive therapeutic target 4.
- A case report published in 2012 found that adenosine can cause severe bronchospasm in a patient without pulmonary disease, highlighting the need for caution when administering adenosine 7.
- Theophylline, a medication used to treat asthma, has been shown to inhibit adenosine-induced bronchoconstriction, increasing the threshold for adenosine-induced bronchoconstriction 3.