What is a common adverse effect associated with the use of theophylline?

Theophylline is a bronchodilator commonly used in the management of respiratory conditions such as asthma and chronic obstructive pulmonary disease (COPD). One of the well-documented adverse effects of theophylline is tachycardia, which is an increased heart rate. This occurs because theophylline can stimulate the central nervous system and increase myocardial contractility, leading to elevated heart rates.

The risk of tachycardia can be influenced by various factors, including dosage and individual patient sensitivity. Monitoring for this side effect is essential in patients being treated with theophylline, especially those who may be on multiple medications that can similarly affect cardiovascular function.

In contrast, weight gain, drowsiness, and skin rash are not typically associated with theophylline use. Weight gain is more commonly related to other medications, drowsiness does not align with the stimulant effects of theophylline, and while skin rashes can occur with many drugs, they are not a hallmark adverse effect of theophylline therapy. Therefore, tachycardia stands out as a significant and frequent adverse effect that healthcare providers need to monitor in patients receiving this medication.