Does Robitussin-DM Cause A False Positive Drug Test Report For Methamphetamine?

Hi I am trying to find out some information. I recently had my children and my exes husband as well as my self drug tested due to my expectations husband s behavior. My children tested positive for meth but yet I did not nor did my exes husband. I was told that the medication my children were taking at the time could have caused a false positive for meth. I am trying to find out if that information is correct as I am trying to get a confirmation test done to prove it. But I was told I needed to seek professional help in researching this. Could you please get back to me with the answer. I have done research on my own that does state that children s Robitussin dm as well as the add medication concerta can cause a false positive for meth due to the base drug used to manufacture these medications. But I need confirmation of some form either email or a written statement from a licenced physician to confirm my findings. Could you please help me. Thanks in advance Alexis alexander