Answer:
Smoking cigarettes may decrease serum theophylline levels. Intact some patients who smoke require an increase in serum theophylline dosage of up to 50%.
Step-by-step explanation:
Smoking smokers on theophylline tends to require higher doses than non smokers because tobacco contains polycyclic hydrocarbons(nicotine) which induces CYPIA2 ( more rapid clearance of theophylline).