Ranitadine can interact with Statins so they advise not to take them together. I don't know about Gaviscon but Sara's advice seems the best thing to do. If you are reading this Sqad please come back you really are needed on H&F.
My husband used to take both ranitadine and simvastatin together, and he took them for a long time. He is now on a different statin and takes gaviscon on prescription - but he doesn't take ranitadine anymore.