Does adenosine cause tiredness?

Does Adenosine Cause Tiredness?

Yes, adenosine can cause tiredness and fatigue as a side effect, though these symptoms are typically transient due to its very short half-life of approximately 20 seconds in human blood. 1, 2

Mechanism of Action and Tiredness

• Adenosine is a naturally occurring nucleoside that acts on purinergic receptors, particularly A1 receptors in cardiac tissue and A2 receptors in vascular tissue 2
• Adenosine is a key endogenous regulator of sleep-wake cycles in the brain, with increasing levels promoting drowsiness and sleep 2
• When administered therapeutically, adenosine can cause transient side effects including:
  • Flushing (common)
  • Chest discomfort/pain (common)
  • Dyspnea or shortness of breath
  • Dizziness and lightheadedness
  • Fatigue and tiredness 1, 2

Clinical Applications and Side Effect Profile

• Adenosine is primarily used for terminating supraventricular tachycardias (SVTs), particularly AV nodal re-entrant tachyarrhythmias 1
• Administered as a rapid IV bolus (6mg initially, followed by 12mg if needed) 1
• Side effects are generally transient due to adenosine's extremely short half-life of approximately 20 seconds 1, 2
• Common patient experiences include:
  • Transient chest discomfort
  • Shortness of breath
  • Flushing
  • Headache
  • Throat/neck/jaw discomfort
  • Gastrointestinal discomfort
  • Dizziness and fatigue 2

Important Clinical Considerations

• Adenosine must be administered in a monitored environment (e.g., critical care unit or emergency department) due to potential for transient complete heart block 1
• Contraindicated in patients with:
  • Severe asthma (risk of bronchospasm)
  • Second or third-degree AV block (in absence of pacemaker)
  • Sick sinus syndrome 1, 2
• Use with caution in patients taking:
  • Dipyridamole (potentiates adenosine effects)
  • Theophylline, caffeine (antagonizes adenosine effects)
  • Carbamazepine (increased risk of heart block) 1, 2

Pharmacokinetics Related to Tiredness

• Adenosine is rapidly removed from the blood by:
  • High-affinity red blood cell uptake mechanism
  • Direct deamination
  • Half-life in human blood is only about 20 seconds 1
• This short half-life explains why tiredness and other side effects are typically very brief 1, 2
• During intravenous adenosine administration, patients should avoid Valsalva maneuvers as this can interrupt continuous drug delivery and may affect both the therapeutic effect and side effect profile 1

In summary, while adenosine can cause transient tiredness, this side effect is typically very brief due to the drug's extremely short half-life and is generally not a major clinical concern in the context of its therapeutic use for arrhythmias.