A pharmaceutical composition comprising a pharmaceutically-acceptable carrier, a tramadol material and a phosphodiesterase (PDE) inhibitor, a pharmaceutical composition comprising a pharmaceutically-acceptable carrier, a phosphodiesterase (PDE) inhibitor and an opioid antagonist, a kit comprising a container holding a tramadol material and a phosphodiesterase (PDE) inhibitor； or a first container holding a tramadol material and a second container holding a phosphodiesterase (PDE) inhibitor and a kit comprising one or more containers, each of which holds a tramadol material, a phosphodiesterase (PDE) inhibitor, an opioid antagonist or a combination of two or more of the foregoing.
