When Cersobleptes negotiated with Philip II of Macedonia for a combined attack on the Chersonese, Amadocus refused to allow Philip passage through his territory, in consequence of which the scheme came to nothing.
Both Amadocus and Cersobleptes appear to have been subjected by Philip early in 347 BC, not long after Cetriporis, the son and successor of Berisades, suffered the same fate. The two rulers, having appealed to the Macedonian ruler to arbitrate a dispute between them, were then been forced to acknowledge his suzereinty when the "judge" showed up with an army.
Amadocus seems to have had a son of the same name. His successor, however, appears to have been Teres III.