Zantac and not sleeping

It seems like Jack hasn’t been sleeping well since we started the Zantac at bedtime (2ml). I’m wondering if anyone else’s children showed signs of restlessness or sleeplessness after taking Zantac. I’m still so mad at the Nurse Practitioner for refusing to go back to the solutabs at the dose that he was on. He was just starting to sleep good at night. Now we’re at square one again.