Topical minoxidil: Review of efficacy

Abstract

Hypertrichosis occurs as an undesirable adverse reaction in the majority of hypertensive patients treated with minoxidil (Loniten tablets, Upjohn Company, Kalamazoo, MI).1–3 Nevertheless, its potential topical use for the treatment of alopecia4 has caused much publicity and interest in several topical formulations of minoxidil recently available to selected patient populations. First, patients have participated in sanctioned Investigational New Drug studies using unique investigational formulations of The Upjohn Company. Secondly, patients have received Upjohn's topical 2% minoxidil solution marketed in a country outside of the United States, such as Canada. Lastly, patients have had a local pharmacist prepare an extemporaneous minoxidil solution from Loniten tablets.5,6The pharmacodynamics of such extemporaneous preparations are variable and may not be directly comparable to Upjohn's unique marketed product. Consequently in 1985, the Food and Drug Administration (FDA) issued an order to halt the use of Loniten Tablets for preparing extemporaneous topical minoxidil solutions for alopecia5; however, such nonapproved usage constituted by far the major route of exposure to topical minoxidil.7