Use of Medication when using Food Intolerance testing kits
Use of antihistamine drugs (e.g. Claritin, Zyrtec, Benadryl) will not affect IgG antibody testing as these tests measure immune response and not histamine levels. Therefore these tests can be carried out whilst taking anti-histamine medication.
If a client is on Warfarin this should not affect the results but as it is a blood thinner it may affect taking the blood sample and may promote bleeding afterwards. If unsure ask the client to check with their medical practitioner or pharmacist, bearing in mind it is only a single finger-prick blood sample taken using a lancet similar to those used by diabetics for blood glucose readings.
There is no evidence that antibiotics have any affect on B or T cells, and hence no evidence that IgG antibody levels will be affected.
IgG antibody testing is not useful for people on immunosuppressant drugs (especially if they have been on the drugs for longer than 1 month – see below). These drugs may affect results and therefore we cannot guarantee accuracy. This includes all corticosteroids such as Prednisolone, Budesonide and Dexamethasone; plus other immunosuppressants such as Azathioprine and Cyclosporine. (As far as we know, results are not affected by inhalers for asthma).
It is recommended that the blood sample for an IgG antibody test should not be taken until the patient has been off immunosuppressant drugs for 4-6 weeks*. Conversely the test can be done if the client has only just started their medication and been taking the drugs for less than 4 weeks (as there will still be sufficient antibodies present to be detected).
If a client is taking any of these medications and still wants to go ahead with the test then the following difference in results could be expected
*It is extremely important that patients do not come off any prescription medication without medical supervision. Unmanaged change in drug dosage can result in extreme adverse consequences. Steroids (or corticoids) in particular should not be stopped without advice from a medical practitioner as they need to be reduced at a controlled rate.