Medication - CNSLab


                 Use of Medication when using Food Intolerance testing kits

Antihistamine Drugs
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.

Immunosuppressant Drugs
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

  •  Medication for less than 1 month: No difference in results
  • Medication for 1-2 months : This may give a lower reaction intensity and therefore the results should be interpreted as a slightly higher reading on the Foodprint (U/ml) or a slightly darker blue on the Food Detective than is actually reported or shown.
  • Medication for 2-3 months: The FoodPrint concentrations (U/ml) should be multiplied by 2; and the Food Detective results should be interpreted as a darker blue than is actually shown.
  • Medication is in place for > 3 months: It is unlikely that results will be obtained for both FoodPrint and Food Detective, therefore the tests are not recommended.

*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.