Dietary Restrictions for Urine Tests
Observing Dietary Restrictions Avoids False Urine Test Results
Certain foods and drugs ingested before or during the collection of a urine specimen can interfere with the accurate results of some tests. In general, you should observe the dietary restrictions listed here if you have one of these tests. If, however, your test is not listed here, there are no dietary restrictions you need to observe. Consult your doctor before discontinuing any medications, or if you are unsure whether a drug you are taking is listed here. In any case, always follow your doctor’s specific instructions for the test ordered.
Metanephrine Urine Test
If your doctor has ordered a test for metanephrine in your urine, you should avoid caffeine for 24 hours and during collection of your specimen. In addition, the following drugs should be avoided for one week prior to the collection, if clinically feasible:
- Phenothiazines (used to treat mental or emotional disorders)
- Tricyclic antidepressants including imipramine, as well as labetalol, sotalol and monoamine oxidate inhibitors (MAOIs)
- Chlorpromazine (used to treat psychosis)
Caution: do not stop taking any medications without prior approval from your physician.
Vanillylmandelic Acid (VMA) Urine Test
If your doctor has ordered a test for VMA in your urine, you should avoid high doses (as determined by your physician) of the following substances for a minimum of 24 hours before, as well as during, collection of your specimen:
- Triamterene (used to treat high blood pressure and fluid retention)
- Octopamine (found in drugs such as Norfen, Norden and Epirenor)
- Phenolic amines (found in fruit juices and bananas)
- Phenylpyruvic acid
You also should avoid the drugs labetalol and methyldopa, both of which are used to treat high blood pressure.
Caution: do not stop taking any medications without prior approval from your physician.
Hydroxyindoleacetic Acid (5HIAA) Urine Test
If your doctor has ordered a test for 5HIAA in your urine, you should avoid the following foods and drugs for at least a 48-hour period before and during collection of your specimen:
- Bananas
- Avocadoes
- Plums
- Cantaloupe and honeydew melon
- Dates
- Hickory nuts
- Grapefruit
- Kiwi
- Eggplant
- Tomatoes
- Pineapples
- Walnuts
- Plantain
- Pain relievers (specifically those containing acetaminophen, salicylates or phenacetin)
- Cough syrups containing glyceryl guaiacolate
- Muscle relaxants containing mephenesin or methocarbamol
- Antidepressants including imipramine and monamine oxidase inhibitors (MAOIs)
- Isoniazid (antibiotic used to fight tuberculosis and other diseases)
- Methenamine (antibiotic used to fight urinary tract infections)
- Methyldopa (used to treat high blood pressure)
- Phenothiazines (used to treat mental or emotional disorders)
Caution: do not stop taking any medications without prior approval from your physician.
Catecholamines Urine Test
If your doctor has ordered a test for catecholamines in your urine, it is preferred if you take no medications for three days prior to collecting a specimen. (However, certain common hypertensives, such as diuretics, ACE inhibitors, calcium channel blockers, and alpha and beta blockers, are okay to take.) For 24 hours prior to collecting the specimen, you should avoid strenuous exercise as well as the following substances and drugs:
- Acetaminophen
- Alcohol
- Antihistamines
- Aspirin
- Caffeine
- Vitamin B
Caution: do not stop taking any medications without prior approval from your physician.
Michigan law requires that a valid order signed by an authorized person be presented before any laboratory test or procedure can be conducted. Authorized persons are defined as physicians, physician assistants, or nurse practitioners. These professionals are legally responsible for interpreting the results of tests based on their knowledge of the individual patient.
