The Letter to the Editor, “Tolerance and Dependence Risk with the Use of Carisoprodol,” by Craig Heacock, M.D., and Mark S. Bauer, M.D. (April 1, 2004, page 1622), incorrectly stated that meprobamate is a schedule IV barbiturate with a long history of abuse. The second sentence in the first paragraph of the letter should have stated that meprobamate is a schedule IV drug that has a long history of abuse and exhibits cross-tolerance to barbiturates. Meprobamate is a bis-carbamate ester and is not a member of the barbiturate family. The online version of this letter has been corrected.