Yes they are interchangeable.
I have 2 1997 Megane Scenics and have had to change the coil packs on them both.
Take care to get the correct ones though as the design is different on my 2000L RXE and my 1.6L. One has female connectors and the other type male. The local garage told me the sort for my RXE was discontinued and gave me the other sort which meant I also had to buy a new set of spark plug leads (£30). A few months later I was told they weren't discontinued!
RobertK, August 2010