What should be monitored in patients receiving theophylline therapy?

Monitoring serum theophylline levels in patients receiving theophylline therapy is crucial due to the drug's narrow therapeutic window. Theophylline is a xanthine derivative used as a bronchodilator, and plasma concentrations need to be carefully managed to avoid toxicity. Elevated levels can lead to side effects such as tachycardia, nausea, and even seizures, while levels that are too low may not provide effective bronchodilation.

Serum theophylline levels provide a direct measurement of the drug concentration in the blood, allowing healthcare providers to adjust dosages as necessary for optimal therapeutic effect while minimizing the risk of toxicity. Regular monitoring is especially important in patients with fluctuating conditions that might affect theophylline metabolism, such as liver function, smoking status, or the addition of other medications that could interact with theophylline.