Combination Of Isosorbide Research Articles

Use of Isosorbide Dinitrate/Hydralazine in the Pediatric Cardiac Population

<h3>Purpose</h3> The combination of isosorbide dinitrate/hydralazine (ISDN/HYD) offers direct arterial and venous vasodilation without adversely affecting renal function. It is used as an adjunct to standard heart failure therapies in adults with reduced ejection fraction. ISDN/HYD is an attractive option in pediatric cardiac patients who may not tolerate angiotensin converting enzyme inhibitors due to renal dysfunction from inadequate systemic cardiac output, nephrotoxic medications, or young age. Given the lack of published reports of its use in children, we report our experience with ISDN/HYD in a heterogeneous population of pediatric cardiac patients. <h3>Methods</h3> From an internal database, we identified all patients treated with ISDN/HYD. Patient characteristics at ISDN/HYD initiation, 3-months, discontinuation, and latest follow-up were abstracted from the chart. ISDN/HYD was dosed TID at a dose ratio of 1:2 ISDN:HYD. <h3>Results</h3> There were 59 patients treated with ISDN/HYD for a mean duration of 14 ± 14 months. Patient characteristics are summarized in Table 1. The mean age was 3.8 years, while those with single ventricle anatomy were mostly infants. Over half had a prior diagnosis of acute kidney injury. The majority of patients were initiated during a hospitalization. In addition to heart failure, ISDN/HYD was used in stage 1 single ventricle patients to reduce pulmonary over-circulation. Brain natriuretic peptide decreased from initiation to 3 months (782 vs 312 pg/mL, p=0.0007, n = 42), and left ventricular fractional shortening increased (29 vs 32%, p=0.013, n=32). <h3>Conclusion</h3> As demonstrated in this case series, ISDN/HYD is used across a heterogeneous pediatric cardiac population where acute kidney injury is common. Short-term follow up after ISDN/HYD initiation showed a reduction in BNP and a modest improvement in left ventricular systolic function. Further study is needed to define indications, side effects, and better understand outcomes of ISDN/HYD use in the pediatric cardiac population.

Vasodilator Therapy for Acute Heart Failure

Haemodynamic comparison of three vasodilation regimens [intravenous (i.v.) hydralazine and isosorbide dinitrate (ISDN) combined, i.v. doxazosin, and i.v. enalaprilat] was undertaken in 36 patients with acute left ventricular (LV) failure due to recent myocardial infarction. Each regimen achieved similar reductions in pulmonary artery occluded pressure (PAOP, preload) and systemic arterial pressures (afterload), with increased cardiac and stroke volume (SV) indexes (p less than 0.01). Only the hydralazine and isosorbide combination induced resting tachycardia. Balanced vasodilatation after selective alpha-adrenoceptor blockade (doxazosin) and angiotensin-converting enzyme (ACE) inhibition (enalaprilat) without increase in heart rate (HR) suggests that these therapies may have definite haemodynamic advantages over the hydralazine/ISDN combination.

Comparison of nifedipine and isosorbide dinitrate when added to maximal propranolol therapy in stable angina pectoris

A study was performed to compare isosorbide dinitrate and nifedipine as adjunctive therapy in 14 patients with coronary artery disease and stable angina pectoris taking maximal β-blocking drugs. Drug titration phases ensured maximal therapy of propranolol, isosorbide or nifedipine. The combination of nifedipine and propranolol was more effective than the combination of isosorbide and propranolol in reducing angina and increasing exercise capacity (323 vs 416 seconds, p <0.005) during exercise treadmill testing. Nifedipine produced a greater reduction in systolic blood pressure at submaximal exercise than isosorbide. Global and regional ejection fraction at rest and exercise was assessed with radionuclide ventriculography. The substitution of nifedipine for isosorbide depressed the global ejection fraction at rest (0.61 to 0.56 p <0.05) and produced a slight improvement in exercise ejection fraction (0.47 to 0.51, difference not significant). The decrease in ejection fraction from rest to exercise was 0.14 to 0.04 with nifedipine (p <0.005). The benefit of nifedipine compared with isosorbide occurred in regions with marked exercise-induced ischemia. In patients treated with maximal β-blocking therapy, nifedipine is an effective alternative to isosorbide as a combination agent with propranolol. The salutary effects of nifedipine included afterload reduction with exercise and possible improvements in coronary blood supply.