Is the tragedy in Oedipus Rex similar to that in Antigone?

Yes, the tragedy in Oedipus Rex is similar to that in Antigone if we consider the definition of tragedy as posited by Aristotle.  In both plays, there is a tragic hero--Oedipus and Creon respectively--who is of noble birth and suffers hamartia.  Both Oedipus and Creon are challenged by respected members of the community to reconsider their actions and positions on the issues:  the murder of Laius and the burying of Polynices.  But Oedipus and Creon have too much pride to consider that their actions are misguided, and instead, they both accuse Teiresias of being bribed to speak his prophecies.  In the end, both Oedipus and Creon achieve catharsis and try to make the situation right:  Oedipus takes his own sight as punishment, and Creon attempts to free Antigone from the tomb although he is too late.  So, the mode of tragedy in both Oedipus Rex and Antigone are similar.