What effect does tobacco have on the amount of theophylline in the bloodstream?

Tobacco smoke contains numerous chemicals that can affect the metabolism of various medications, including theophylline. Specifically, constituents in tobacco can induce liver enzymes, particularly cytochrome P450 enzymes. Theophylline is metabolized in the liver by these enzymes, so when tobacco use induces an increase in enzyme activity, it accelerates the metabolism of theophylline. As a result, this leads to a decrease in the concentration of theophylline in the bloodstream. Hence, the use of tobacco can lead to lower levels of theophylline, which may reduce its effectiveness in treating conditions like asthma or chronic obstructive pulmonary disease (COPD).

Understanding this interaction is crucial for healthcare providers when prescribing theophylline to patients who smoke, as they may require different dosing or monitoring strategies compared to non-smokers.