Drug Interactions between isosorbide and sapropterin

Consumer information for this interaction is not currently available.

MONITOR: Coadministration of phenylalanine hydroxylase (PAH) activators (e.g., sapropterin and sepiapterin) with nitric oxide-mediated vasodilators, including phosphodiesterase-5 (PDE5) inhibitors and other agents affecting nitric oxide metabolism, may potentiate hypotensive effects. The proposed mechanism involves PAH activators increasing the availability of tetrahydrobiopterin (BH4), an essential cofactor for nitric oxide synthase (NOS), thereby enhancing nitric oxide production and subsequent vasodilation. Theoretically, the additive effects on vasodilation could lead to a reduction in blood pressure, although combined use of these medications has not been evaluated in humans.

MANAGEMENT: Caution and closer monitoring for signs and symptoms of hypotension are advised when a phenylalanine hydroxylase (PAH) activator (e.g., sapropterin or sepiapterin), is used in combination with nitric oxide-mediated vasodilators, including topical drugs. Patients should be advised to contact their physician if they experience signs of hypotension such as dizziness, fainting, tachycardia, and headache.