What is the typical effect of smoking cigarettes on theophylline metabolism?

What is the typical effect of smoking cigarettes on theophylline metabolism?

• A. Decrease hepatic clearance
• B. Increase hepatic clearance
• C. No effect on hepatic clearance
• D. Increase absorption

Answer: (B)

The correct response indicates that smoking cigarettes significantly increases hepatic clearance of theophylline. This occurs due to the induction of hepatic enzymes, particularly cytochrome P450 enzymes, which are involved in the metabolism of theophylline. The numerous substances in cigarette smoke, including polycyclic aromatic hydrocarbons, stimulate these enzymes, thereby enhancing the breakdown of theophylline in the liver. As a result of this increased clearance, individuals who smoke may require higher doses of theophylline to achieve therapeutic effects, as their bodies metabolize the drug more rapidly than those who do not smoke. Understanding this interaction is crucial for healthcare providers when prescribing theophylline, as it impacts dosing and therapeutic monitoring in smokers compared to non-smokers.

The correct response indicates that smoking cigarettes significantly increases hepatic clearance of theophylline. This occurs due to the induction of hepatic enzymes, particularly cytochrome P450 enzymes, which are involved in the metabolism of theophylline. The numerous substances in cigarette smoke, including polycyclic aromatic hydrocarbons, stimulate these enzymes, thereby enhancing the breakdown of theophylline in the liver.

As a result of this increased clearance, individuals who smoke may require higher doses of theophylline to achieve therapeutic effects, as their bodies metabolize the drug more rapidly than those who do not smoke. Understanding this interaction is crucial for healthcare providers when prescribing theophylline, as it impacts dosing and therapeutic monitoring in smokers compared to non-smokers.