Comparative Pharmacology
Head-to-head clinical analysis: DILATRATE SR versus ISOSORBIDE DINITRATE AND HYDRALAZINE HYDROCHLORIDE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: DILATRATE SR versus ISOSORBIDE DINITRATE AND HYDRALAZINE HYDROCHLORIDE.
DILATRATE-SR vs ISOSORBIDE DINITRATE AND HYDRALAZINE HYDROCHLORIDE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
DILATRATE-SR (isosorbide dinitrate) is a vasodilator that relaxes vascular smooth muscle via the release of nitric oxide (NO), which activates guanylate cyclase, increasing cGMP levels. This leads to venous and arterial dilation, reducing preload and afterload.
Isosorbide dinitrate is a vasodilator that relaxes vascular smooth muscle via nitric oxide-mediated increases in cyclic guanosine monophosphate (cGMP), leading to venodilation and reduced preload. Hydralazine is a direct arteriolar vasodilator that reduces afterload. Combination therapy improves cardiac output in heart failure.
40 mg orally twice daily, 6–8 hours apart, as sustained-release formulation. Maximum dose: 160 mg twice daily.
Isosorbide dinitrate 20 mg plus hydralazine hydrochloride 37.5 mg (1 tablet) orally three times daily; may titrate to target dose of isosorbide dinitrate 40 mg plus hydralazine hydrochloride 75 mg (2 tablets) three times daily as tolerated.
None Documented
None Documented
Terminal half-life is 4-6 hours, but clinical effect lasts 8-12 hours due to sustained-release formulation.
Isosorbide dinitrate: terminal half-life 5-6 hours for active metabolites (isosorbide-5-mononitrate); hydralazine: terminal half-life 2-8 hours (increases with renal impairment), clinically relevant for dosing interval.
Renal excretion of inactive metabolites accounts for approximately 60-80% of clearance, with biliary/fecal elimination contributing 20-40%.
Isosorbide dinitrate: primarily renal (urine) as metabolites, ~80% excreted renally; hydralazine: extensively metabolized, ~85% excreted renally as metabolites, 10% as unchanged drug in urine, minor biliary/fecal elimination.
Category C
Category A/B
Nitrate
Nitrate