My 85 yr.old grandma has terrible gerd, the only thing that helps is reglan (metoclopramide). but this is not supposed to be used long term. what else can be done?

She needs it, use it: Likely any medicine, we recommend using the lowest effective for the shortest duration possible. Some people needs life-long treatment! if she uses and is benefiting from it without causing significant side effects, then it is reasonable to continue. If having side effects, then look for alternative. At her age and doing well, she should have whatever she needs that helps w/o harm. Good luck.