Harrical - General Information
A vasodilator used in the treatment of angina pectoris. Its actions are similar to nitroglycerin but with a slower onset of action. [PubChem]
Pharmacology of Harrical
Harrical is a moderate to long acting oral organic nitrate used for the relief and prophylactic management of angina pectoris. It relaxes the vascular smooth muscle and consequent dilatation of peripheral arteries and veins, especially the latter. Dilatation of the veins promotes peripheral pooling of blood and decreases venous return to the heart, thereby reducing left ventricular end- diastolic pressure and pulmonary capillary wedge pressure (preload). Arteriolar relaxation reduces systemic vascular resistance, systolic arterial pressure, and mean arterial pressure.
Harrical for patients
Patients should be told that the anti-anginal efficacy of isosorbide dinitrate is strongly related to its dosing regimen, so the prescribed schedule of dosing should be followed carefully. In particular, daily headaches sometimes accompany treatment with isosorbide dinitrate. In patients who get these headaches, the headaches are a marker of the activity of the drug. Patients should resist the temptation to avoid headaches by altering the schedule of their treatment with isosorbide dinitrate, since loss of headache may be associated with simultaneous loss of anti-anginal efficacy. Aspirin and/or acetaminophen, on the other hand, often successfully relieve isosorbide dinitrate- induced headaches with no deleterious effect an isosorbide dinitrate's anti-anginal efficacy.
Treatment with isosorbide dinitrate may be associated with lightheadedness on standing, especially just after rising from a recumbent or seated position. This effect may be more frequent in patients who have also consumed alcohol.
The vasodilating effects of isosorbide dinitrate may be additive with those of other vasodilators. Alcohol, in particular, has been found to exhibit additive effects of this variety.
Allergic reactions to organic nitrates are extremely rare, but they do occur. Isosorbide dinitrate is contraindicated in patients who are allergic to isosorbide dinitrate or any of its other ingredients.
Additional information about Harrical
Harrical Indication: For the prevention of angina pectoris due to coronary artery disease.
Mechanism Of Action: Similar to other nitrites and organic nitrates, isosorbide dinitrate is converted to nitric oxide (NO), an active intermediate compound which activates the enzyme guanylate cyclase (atrial natriuretic peptide receptor A). This stimulates the synthesis of cyclic guanosine 3',5'-monophosphate (cGMP) which then activates a series of protein kinase-dependent phosphorylations in the smooth muscle cells, eventually resulting in the dephosphorylation of the myosin light chain of the smooth muscle fiber. The subsequent release of calcium ions results in the relaxation of the smooth muscle cells and vasodilation.
Drug Interactions: Dihydroergotamine Possible antagonism of action
Dihydroergotoxine Possible antagonism of action
Ergonovine Possible antagonism of action
Ergotamine Possible antagonism of action
Methylergonovine Possible antagonism of action
Methysergide Possible antagonism of action
Sildenafil Possible significant hypotension with this combination
Tadalafil Possible significant hypotension with this combination
Vardenafil Possible significant hypotension with this combination
Food Interactions: Take without regard to meals. Absorption is faster on an empty stomach.
Generic Name: Isosorbide Dinitrate
Synonyms: Dianhydrosorbitol 2,5-dinitrate; Sorbide nitrate; Sorbide, dinitrate; Sorbidnitrate
Drug Category: Vasodilator Agents; Nitrates and Nitrites
Drug Type: Small Molecule; Approved
Absorption: Absorption of isosorbide dinitrate after oral dosing is nearly complete, but bioavailability is highly variable (10% to 90%), with extensive first-pass metabolism in the liver. The average bioavailability of isosorbide dinitrate is about 25%.
Toxicity (Overdose): Symptoms of overdose include reduced cardiac output and hypotension.
Protein Binding: Very low
Half Life: 1 hour
Dosage Forms of Harrical: Tablet, extended release Oral
Chemical IUPAC Name: [(3S,3aS,6R,6aS)-6-nitrooxy-2,3,3a,5,6,6a-hexahydrofuro[2,3-d]furan-3-yl] nitrate
Chemical Formula: C6H8N2O8
Isosorbide Dinitrate on Wikipedia: Not Available
Organisms Affected: Humans and other mammals