I don't see how. Nihilism is descriptive whereas hedonism is prescriptive.
Nihilism is an answer to the question of what is or is not, to which is says, "not at all". That's why there are many flavors of nihilism, such as existential nihilism ("there is no meaning at all"), moral nihilism ("there is no morality at all"), or epistemic nihilism ("there is no knowledge at all").
Contrast hedonism, which is an answer to the question of what one ought to do with one's time, or to put another way, it's a min-max strategy where pain is minimized and pleasure is maximized.
I don't see how those two areas of philosophy contradict each other in any way.