What blood test is used to monitor the effectiveness of theophylline?

The serum theophylline level is the specific blood test used to monitor the effectiveness of theophylline therapy. Theophylline is a xanthine derivative that is commonly prescribed for conditions such as asthma and chronic obstructive pulmonary disease (COPD) because it acts as a bronchodilator and helps to relax the muscles around the airways. Monitoring serum theophylline levels is crucial as this medication has a narrow therapeutic range. This means that too low of a level may not provide the desired therapeutic effects, while too high a level can lead to toxicity and serious side effects, such as tachycardia, palpitations, nausea, and central nervous system stimulation.

Other types of blood tests, such as a complete blood count, liver function tests, and arterial blood gas analysis, while useful in different clinical situations, do not specifically assess the effectiveness of theophylline medication. A complete blood count evaluates overall health and detects various disorders, while liver function tests assess the health of the liver, and arterial blood gas analysis measures the levels of oxygen and carbon dioxide in the blood. These tests do not provide direct information about the plasma concentration of theophylline or its therapeutic effectiveness.