When Mithridates VI was at last defeated by Pompey and in danger of capture by Rome, he is alleged to have attempted suicide by poison; this attempt failed, however, because of his immunity to the poison.[8][9] According to Appian's Roman History, he then made his Gaul bodyguard and friend, Bituitus, kill him by the sword:

Mithridates then took out some poison that he always carried next to his sword, and mixed it. There two of his daughters, who were still girls growing up together, named Mithridates and Nyssa, who had been betrothed to the kings of [Ptolemaic] Egypt and of Cyprus, asked him to let them have some of the poison first, and insisted strenuously and prevented him from drinking it until they had taken some and swallowed it. The drug took effect on them at once; but upon Mithridates, although he walked around rapidly to hasten its action, it had no effect, because he had accustomed himself to other drugs by continually trying them as a means of protection against poisoners. These are still called the Mithridatic drugs.