The Invention provides indole derivatives of Formula I: [chemical expression included] and pharmaceutically acceptable salts and solvates thereof, wherein R1e, R1f, A, X, Y, Z, and W4 are defined as set forth in the specification. The Invention also provides the use of compounds of Formula I and the pharmaceutically acceptable salts and solvates thereof to treat pain. In certain embodiments, the Compounds of the Invention are effective in treating a disorder responsive to blockade of one or more sodium channels.