The measurement of circulating catecholamines is valuable in the diagnosis of catecholamine secreting tumors associated chiefly with hypertension (pheochromocytomas, neuroblastomas, and gangliomas) and with the evaluation of orthostatic hypotension.
Catecholamines are a group of hormones that are released into the blood in times of stress. The most common catecholamines are adrenaline, norepinephrine, epinephrine and dopamine. These are produced in the adrenal glands and cells of the sympathetic nervous system. These catecholamine can be measured in the blood and their metabolites can be measured in the urine. This test is used for determining adrenal functions, since rare disorders like pheochromocytomas can cause these hormone levels to be abnormal. Therefore, this is a useful test, whether using blood or urine sample, to determine cause in people who have persistent hypertension. Urine sample is slightly more accurate, since having blood taken can cause these hormones to increase.
This test is performed in following conditions such as:
• Persistent high blood pressure
• High blood pressure that does not respond to treatment
• Severe headaches
• Sweating and flushing
• Rapid heart rate
Also Known As: Dopamine, Epinephrine, Adrenaline, Norepinephrine
Avoid stress. Many drugs (reserpine and α-methyldopa, levodopa, monoamine oxidase inhibitors, and sympathomimetic amines) may interfere and should be discontinued two weeks prior to specimen collection. Nose drops, sinus and cough medicines, bronchodilators and appetite suppressants, α2-agonists, calcium channel blockers, converting enzyme inhibitors, bromocriptine, phenothiazine, tricyclic antidepressants, α- and β-blockers, and labetalol may interfere. Mandelamine® interferes, but thiazides do not. Caffeine products should be avoided before and during collection. Increased intracranial pressure and clonidine withdrawal can cause false-positive results1. Avoid alcohol, coffee, tea, tobacco (including the use of nicotine patch), bananas, citrus fruits and strenuous exercise prior to collection. The person being tested should void at 8 AM and discard the specimen. Preservative must be added to the container prior to the start of collection. The preservative may burn the skin so it is recommended not to touch the inside of the specimen container. Then collect all urine including the final specimen voided at the end of the 24-hour collection period (ie, 8 AM the next morning). Refrigerate specimen before returning it to the lab.
Estimated Time Taken
Turnaround for this test is typically 3-6 business days.