The earlier discussion of hyperhidrosis treatment (Item 116-9) didn’t mention alpha blockers, such as clonidine (Catapres) and terazosin (Hytrin). What effect do these agents have on hyperhidrosis?
—Caroline Carson, MD, Newport Beach, Calif.

The role of oral medications in the treatment of hyperhidrosis is limited by a number of factors: medication side effects, limited evidence (mostly of anecdotal benefit in isolated cases), and the emergence of newer, more effective therapies. The oral agents that have been used are primarily clonidine and certain anticholinergics. A centrally acting alpha2-adrenergic agonist, clonidine is a sympathetic inhibitor, has a central thermoregulatory effect, and has been shown to improve symptoms of hyperhidrosis in several small case reports (South Med J. 2000;93:68-69, published correction appears in South Med J. 2000;93:264). Anticholinergic agents, such as glycopyrronium bromide and oxybutynin, can reduce sweating, but in doses high enough to have the desired effect, they also cause many side effects, such as constipation, dry mouth, and urinary retention. Finally, beta blockers, such as propranolol and benzodiazepines, can be useful in stress-induced hyperhidrosis. Terazosin is an alpha1-specific blocker with minimal alpha2 effects and therefore does not affect sweating.
—Susan Kashaf, MD, MPH (122-12)