Male pattern baldness
Following topical application, an average of about 1.4% of the total applied dose is absorbed from the normal intact scalp. Topical Minoxidil absorption is increased by increasing the dose applied, increasing the frequency of dosing and decreasing the barrier function of the stratum corneum. Serum Minoxidil levels and systemic effects resulting from the administration of topical Minoxidil are governed by the drug’s absorption rate through the skin. Following cessation of topical dosing, approximately 95% of the systemically absorbed drug is eliminated within 4 days. Minoxidil and its metabolites are excreted principally in the urine.
Signs and symptoms of Minoxidil overdosage would primarily be cardiovascular effects associated with sodium and water retention, and tachycardia. Fluid retention can be managed with appropriate diuretic therapy. Clinically significant tachycardia can be controlled by administration of a beta-adrenergic blocking agent.