Passage 10.23.12
τοῖς δὲ φεύγουσιν ὁμοῦ τῷ Βρέννῳ καὶ οἱ περὶ τὸν Ἀκιχώριον ἐν τῇ προτέρᾳ νυκτὶ ἀνεμίχθησαν· βραδεῖαν γὰρ τὴν πορείαν ἐποίησάν σφισιν οἱ Αἰτωλοὶ τοῖς τε ἀκοντίοις ἐς αὐτοὺς ἀφειδέστερον καὶ ὅτῳ τύχοιεν καὶ ἄλλῳ χρώμενοι, ὥστε ἐς τὸ στρατόπεδον τὸ πρὸς τῇ Ἡρακλείᾳ μοῖρα οὐ πολλὴ διέφυγεν ἐξ αὐτῶν. τῷ δὲ Βρέννῳ κατὰ μὲν τὰ τραύματα ἐλείπετο ἔτι σωτηρίας ἐλπίς· τῶν δὲ πολιτῶν φόβῳ φασὶν αὐτὸν καὶ τῇ αἰδοῖ πλέον, ἅτε τῶν ἐν τῇ Ἑλλάδι κακῶν αἴτιον, ἑκουσίως ἀφεῖναι τὴν ψυχὴν ἀκράτου πίνοντα τοῦ οἴνου.
Those who fled along with Brennus joined with the men around Akichorius during the previous night. The Aetolians had made their march slow, attacking them unsparingly with javelins and whatever other weapons were available, so that only a small portion of them escaped to the camp near Heracleia. As for Brennus, despite his wounds, there still remained some hope of survival; but they say that, overcome more by fear of his countrymen and shame at being the instigator of the disasters in Greece, he willingly ended his life by drinking unmixed wine.