The present invention provides a method of inhibiting symptoms associated with opioid withdrawal in a human subject in need thereof. The method comprises administering an effective amount of a pharmaceutical composition to the subject during an opioid withdrawal period, wherein the pharmaceutical composition comprises: a) a non-steroidal anti-inflammatory drug (NSAID)； and b) a co-agent selected from the group consisting of: fexofenadine, ketotifen, desloratadine and cetirizine and combinations thereof.
