Advice on ranitadine please

Our little boy who is 8 weeks old was diognosed with silent reflux 3 weeks ago and was put onto infant gaviscon, and on the great advice of somebody on this site bought him a natures nest to help him settle at night. This combination had been working great up till a few days ago, so for the past 5 days things have gone back to how they were before the gaviscon, the natures nest still helps him stay asleep but the night time feeds have become a big struggle again and the grunting and thrashing around while he sleeps have returned. Went to gp today and he has put him on ranitadine. Now reading some threads on here has got us a little worried as some people have been saying that it actually makes things worse, so what we are after is some adivse and your own personal experiances of using ranitidine. How long does it take to work? Can we carry of with the gaviscon along with the ranitadine? What are the possible problems and side effects? Will it help? Sorry for all the questions but as you can probably tell our gp isnt the most forthcoming!!!