Medicis (MRX) is falling after the company disclosed in an SEC filing that it had been sued by dermatological product maker Q-Med. The lawsuit alleges that Q-Med has the right to block Medicis' pending merger with Valenant Pharmaceuticals (VRX). Q-Med, whose dermal filler products are sold by Medicis, is asking a court to affirm that it has the right to block the merger, as well as a preliminary injunction that would prohibit Medicis from transferring to Valeant its right to distribute Q-Med products. Valeant agreed to buy Medicis for $44 per share in September. In early afternoon trading, Medicis fell $2.72, or 6.27%, to $40.39.