What is the contraindication for administering Adenosine in adults?

The contraindication for administering Adenosine in adults primarily relates to its effects on cardiac rhythm. Adenosine is particularly effective in treating certain types of supraventricular tachycardia (SVT) by temporarily blocking conduction through the atrioventricular (AV) node. However, in patients with known atrial fibrillation (AFIB) or atrial flutter, Adenosine may not only be ineffective but also potentially harmful. This is because the use of Adenosine in the presence of these conditions can lead to rapid ventricular response due to the irregular atrial activity, increasing the risk for more severe complications, such as hemodynamic instability or worsening of the arrhythmia.

In contrast, other options presented do not reflect direct contraindications based on the pharmacological action of Adenosine. Factors such as body mass index, historical medical issues like seizures, or age-related concerns are not established contraindications for the administration of Adenosine, making the first option the most accurate choice in the context of proper clinical guidelines.