Minoxidil (Dilminox) is an orally active peripheral vasodilator. The pure compound is soluble in water to the extent of approximately 2 mg/ml and is readily soluble in propylene glycol or ethanol. Chemically, Minoxidil (Dilminox) is 2.4-diamino-6-piperidino-pyrimidine-3-oxide. The Molecular Weight is 209.25.Composition
Each uncoated tablet of Dilminox contains Minoxidil I.P. 5 mgPharmacology
Minoxidil (Dilminox) selectively relaxes the arteriolar smooth muscle, which reduces peripheral vascular resistance and lowers systemic blood pressure. This is accomplished without a diminution of nutritional flow to body tissues or interference with normal vasomotor reflexes.
Minoxidil (Dilminox) does not directly stimulate the heart or electrolyte reabsorption of the kidney. However, Minoxidil’s (Dilminox) administration elicits a reflex mediated increase in cardiac output, salt and water retention, and a rise in plasma renin activity. These effects are diminished by the simultaneous administration of diuretics and beta-adrenergic blocking agents.
Gastrointestinal absorption is rapid and amounts to at least 95% of the administered dose. Serum levels of the parent drug peak within the first hour. The plasma elimination half-life of Minoxidil (Dilminox) is approximately 4-4.5 hours, but the duration of its hypotensive action may exceed 24 hours. This disparity between blood level and pharmacological effect and the large volume of distribution indicated extensive tissue localization of the drug. However, on chronic treatment, accumulation does not occur and the pharmacological effect is slowly reversible.
With an effective oral dose, blood pressure usually starts to decline within one — half hour, reaches a minimum between 2 and 3 hours and recovers at a rate of approximately 30%/day.
During daily administration, there is a cumulative effect which reaches a steady state after 3 to 7 days. The magnitude of the blood pressure response is related to the extent of the original diastolic elevation above 85 mm Hg and is proportional to the logarithmic function of the dose administered. When the desired diastolic reduction is greater than 30 mm Hg, twice a day dosing is advised to keep the diurnal variation within 10 mm Hg.
Minoxidil does not bind to plasma proteins, enter the central nervous system or accumulate in body tissues. Metabolism is predominantly by glucuronic acid conjugation. Metabolites are excreted principally in the urine and can be removed by hemodialysis in anephric patients. Hemodialysis does not, however, rapidly reverse the pharmacological effect of Minoxidil.Indications
It is indicated as adjunctive therapy in adults with severe refractory hypertension, which has failed to respond to extensive multiple therapies. When used in combination with an accompanying diuretic and beta-blocker, Minoxidil (Dilminox) has been shown to reverse encephalopathy and retinopathy in severe hypertensives.Contraindications
Minoxidil (Dilminox) is contraindicated in phaeochromocytoma and pulmonary hypertension secondary to mitral stenosis.Warnings
If used alone, Minoxidil (Dilminox) can cause a significant retention of salt and water, producing dependent oedema, puffiness of face, eyes or hands, neck vein distention and hepatojugular reflux. Chest X-rays may show evidence of pulmonary vascular engagement.
Have a requirement?
Get Best Price1