Metadrenalines in urine (catecholamines)

Chemical Pathology

Note

The catecholamine metabolites, normetadrenaline, metadrenaline and 3-methoxytyramine (collectively known as metadrenalines or metanephrines) are the test of choice for the investigation and monitoring of phaeochromocytomas.

Due to the greater sensitivity of this test over the analysis of the catecholamines noradrenaline, adrenaline and dopamine, only a single 24 hour urine collection is now required to screen for these catecholamine producing tumours.

There are however several drugs which can interfere with the assay of urine metadrenalines causing false positive results. Please be sure to list all current medication to aid interpretation of results.

For the investigation and monitoring of suspected neuroblastoma in infants urine VMA and HVA are the preferred tests.

Sample requirements

No special dietary restrictions are required for urine metadrenaline analysis although excess caffeine intake (tea, coffee, caffeine containing drinks etc) and paracetamol should be avoided before and during the collection period.

For older children and adults, a single 24 hour urine collection into a brown 3 L bottle.

Suitable containers are available via the GP surgery, from phlebotomy, Pathology receptions at CGH and GRH or on contacting the laboratory.

If a 24h urine sample is not possible, a fresh spot urine sample (preferably early morning) can be analysed for metadrenaline:creatinine ratios. This requires a minimum of 5mL urine collected into a 30mL Universal and sent immediately to the laboratory. This should be discussed with the duty biochemist to ensure it is the most appropriate test required in these patients where a 24 hour urine collection cannot be obtained.

Storage/transport

• 24 hour urine collections should be sent to the laboratory with a completed request form (direct or via GP surgery), preferably within 24 hours of completion.
• Paediatric spot urine samples need to be sent immediately to the laboratory.
• Acid preservative is added to both these samples on receipt in the laboratory.

Required information

Relevant clinical details including reason for the request, current medication, whether for diagnosis or follow up and any family history.

Essential to note start and finish dates and times of collection.

Turnaround times

Samples are sent to a referral laboratory for analysis with results expected back within 2 weeks.

Reference ranges

Further information

To learn more about urine metadrenalines visit Lab Tests Online

Page last updated: 07/02/2019