The pharmacodynamics of Phyllocontin and Phyllocontin-350 tablets are a function of theophylline blood levels.
Theophylline is a xanthine structurally related to theobromine and caffeine.
As with other xanthine derivatives, the precise mechanism of action of theophylline has not been determined. Theophylline stimulates the CNS and skeletal muscles, stimulates cardiac muscle, relaxes certain smooth muscles including those of the bronchi, produces diuresis, and causes an increase in gastric secretion. Phyllocontin and Phyllocontin-350 tablets are sustained release tablets which produce peak blood levels of theophylline between 3 and 5 hours. Once the steady state level has been reached, the therapeutic blood levels persist for 12 hours. Theophylline is usually readily absorbed following oral administration.