Effective implantable medical devices and methods for reducing and treating acute pain by providing local anesthesia and nerve blockade using an imidazoline compound, such as clonidine are provided. In some embodiments, there is an injectable pharmaceutical composition comprising a therapeutically effective amount of imidazoline compound in a liquid pharmaceutical carrier, where the imidazoline compound provides local anesthesia and nerve block to the target tissue site which is a dorsal root ganglion, peripheral nerve fiber and/or peripheral nerve root.
