Contraindicated in:
Use Cautiously in:
Hydralazine
CV: tachycardia, angina, arrhythmias, edema, orthostatic hypotension.
Derm: rash.
GI: diarrhea, nausea, vomiting.
MS: arthralgias, arthritis.
Neuro: dizziness, headache, drowsiness, peripheral neuritis, weakness.
Misc: drug-induced lupus syndrome.
Isosorbide Dinitrate
CV: hypotension, tachycardia, paradoxical bradycardia, syncope.
GI: abdominal pain, nausea, vomiting.
Misc: flushing, tolerance.
Drug-Drug:
Hydralazine
Absorption: 1026% absorbed in patients with HF following oral administration; absorption can be saturated, leading to large ↑ in absorption with higher doses.
Distribution: Widely distributed to tissues.
Metabolism/Excretion: Mostly metabolized by GI mucosa and liver.
Half-life: 4 hr.
Isosorbide Dinitrate
Absorption: Variable absorption (1090%) following oral administration, reflecting first-pass hepatic metabolism.
Distribution: Accumulates in muscle and venous wall.
Metabolism/Excretion: Undergoes extensive first-pass metabolism in the liver, mostly metabolized by the liver; some metabolites are vasodilators.
Half-life: 2 hr.
(effect on BP)
ROUTE | ONSET | PEAK | DURATION |
---|---|---|---|
hydralazine (PO) | 45 min | 2 hr | 24 hr |
isosorbide (PO) | 1540 min | unknown | 4 hr |