Smoking and Theophylline Dose Schedules

Excerpt

Theophylline is eliminated almost entirely by biotransformation in the liver. It is not surprising that changes in liver function alter the disposition of theophylline: Patients with hepatic cirrhosis have a markedly reduced capacity to eliminate it (1). More subtle changes in liver function associated with alterations in dietary protein and carbohydrate (2) and smoking (3-5) have also been observed.

The enzymes responsible for biotransformation of theophylline in the liver are not known but probably include cytochrome P-448, which can be induced by substances contained in cigarette smoke such as 3,4-benzypyrene and related polycyclic hydrocarbons. This is a different enzyme system