@Bronwyn David,
Hello,
My sister did with her son. She took the bottle completely away at 18 months. However, she eased him into it. She would give him a sippy cup for bedtime and naps, and even if he screamed b/c he wanted the bottle, she didn't give in. Eventually he drank from it at nap and bedtime and she was able to switch him completely to the sippy cup.
Thanks a lot!
Michel Jone