Pardew, who agreed the deal before the start of the season, is enduring his worst run as Newcastle boss, which has included six defeats in their last eight Barclays Premier League games.
But he said: "Because of the length of our deals, there is a suggestion we're not working as hard - it's ridiculous. You work harder in these periods."
He added: "A lot of the players here have only had good times. This is the first time since relegation this club have faced a difficult period and one or two players are finding that difficult to deal with."