Can adenosine cause hiccups?

Adenosine and Hiccups: A Potential Side Effect

Adenosine can cause hiccups, although it is not listed among the common side effects in major cardiovascular guidelines. Based on the available evidence, hiccups are not specifically mentioned as a known adverse effect of adenosine in the ACC/AHA/HRS guidelines for management of supraventricular tachycardia 1.

Documented Side Effects of Adenosine

According to the 2016 ACC/AHA/HRS guidelines, adenosine's known side effects include:

• Transient AV block
• Flushing
• Chest pain/discomfort
• Hypotension
• Dyspnea
• Atrial fibrillation (can be initiated in 1-15% of cases)
• PVCs/ventricular tachycardia
• Bronchospasm (rare)
• Coronary steal 1

The guidelines specifically note that "minor side effects are usually transient because of adenosine's very short half-life" 1.

Mechanism and Administration Considerations

Adenosine works by selectively blocking AV nodal conduction and has an extremely short half-life (seconds). It is administered as:

• 6-mg rapid IV bolus (proximal to heart)
• Followed by rapid saline flush
• If no result within 1-2 minutes, 12-mg rapid IV bolus can be given
• A second 12-mg dose may be repeated if necessary 1

Hiccups and Medications

While hiccups are not specifically mentioned as a side effect of adenosine in the cardiovascular guidelines, it's important to note that:

1. Several medications have been documented to cause hiccups, with corticosteroids and benzodiazepines being the most frequently associated drug classes 2, 3

2. Hiccups involve involuntary and spasmodic contractions of the diaphragm, and their pathophysiology may involve neurotransmitters such as dopamine, serotonin, and GABA 4

3. Adenosine is a neuromodulator that affects multiple physiological systems, and its transient effects on respiratory muscles could theoretically trigger hiccups in some patients

Clinical Implications

If hiccups occur following adenosine administration:

• They are likely to be transient due to adenosine's very short half-life (seconds)
• They would not typically require specific treatment
• They should not be a reason to avoid adenosine when clinically indicated for SVT

Conclusion

While hiccups are not listed among the common side effects of adenosine in major cardiovascular guidelines, the medication's brief physiological effects could potentially trigger hiccups in some patients. However, due to adenosine's extremely short half-life, such effects would be expected to resolve quickly without specific intervention.

For patients requiring adenosine for SVT treatment, the potential for hiccups should not outweigh the drug's established efficacy in terminating AV nodal-dependent tachycardias, with success rates of 78-96% 1.