Drug reference directory
Drug reference

isosorbide dinitrate/hydralazine

Vasodilator · Agent for heart failure

VasodilatorAgent for heart failure
CDSCO approved
EXCRETION
—
not curated
INTERACTIONS
—
none in our sources
PREGNANCY
—
not curated

Mechanism

Isosorbide dinitrate, an organic nitrate, dilates large blood vessels (venous capacitance and arterial conductance vessels), primarily reducing preload. Hydralazine is a direct vasodilator whose mechanism of action is unresolved but may prevent nitrate tolerance by reducing ROS-mediated inactivation of nitric oxide.

Indications

heart failure in African Americans

Dosing

Adult
Fixed combination formulation contains 37.5 mg hydralazine and 20 mg ISDN and is uptitrated to a target dose of two tablets, thrice daily.

Contraindications

  • PDE5 inhibitors

Side effects

Common
dizzinessheadachenauseaflushingpalpitationstachycardiaangina pectoris
Serious
  • hypotension
  • drug-induced lupus-like syndrome

Related guidelines

Other Vasodilator drugs

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Textbook-sourced·Sources: Goodman & Gilman 14e·Updated: 2026-05-10