Tolerance Or Intolerance To Medications

I was wondering if anyone with Chiari or Connective Tissue Disorders ,suffer either tolerance or intolerance to medications.My children and grandchildren{who all have EDS & CM} all suffer from one or the other.For example one pain medication may work,but only for a very short term before becoming almost ineffective.I know this is true of most drugs of this type,but it seems to happen so quickly for us.I have brought this up in response to a post by" Nykki",who expresses the need to "punch someone in the face".Although I don`t condone this ,I certainly know how he or she feels.How many of you feel that the effect Chiari has on the brain and spinal cord could have an effect on the way medications metabolize within our bodies.Has their been any research in this area as my family who has CM all suffer some intolerance to a lot of different drugs.Especially the new synthetic type.With this in mind it is no wonder we get treated with indifference and suspicion from the medical field.Your pain can`t be that bad "it`s only muscular skeletal"That`s the response we commonly get from doctors,hospitals and yes,even pain management specialist,one of which put me on a new drug that made me feel ten times worse.Could anybody tell me what medications work for them,or even the ones that don`t.

Thank you Beeba.It sounds like it could be the tip of a very large "iceberg".Hopefully not.Again I thank you for your wealth of information.