This invention provides a compound selected from the group consisting of L-nicotine(X1)(X2) and D-nicotine(X1) (X2), or a pharmaceutically acceptable salt thereof, wherein (i) each of X1 and X2 is independently a pharmaceutically acceptable anion or a null set and (ii) X1 and X2 cannot both be null sets. This invention also provides related compositions, as well as methods for treating a disorder reasonably believed to be ameliorated by the administration of nicotine.
