A number of drugs including antihypertensive agents (blood pressure medications) and antidepressants may interfere with these urinary tests. Do not restrict or cease these drugs unless advised by your doctor.
You should ensure that your medications are being taken on a regular daily basis for the 3-4 days prior to and during the collection.
In addition, as illness can misleadingly raise the results of these tests, avoid collecting the sample during intercurrent illness (e.g., flu).
When testing for urinary 5-HIAA or serotonin, exclude from your diet all nuts and vegetables or fruit containing seeds for 3-4 days prior to and during the collection. This includes bananas. Some examples of foods to exclude are:
