Positive regitine blocking test

What it means

A positive response to the regitine blocking test consisting of a substantial reduction in blood pressure following administration of regitine, indicative of the presence of increased levels of epinephrine and norepinephrine in the circulation, which is seen in pheochromocytoma-associated hypertension.

Regitine produces an alpha-adrenergic block of relatively short duration. In the regitine blocking test, regitine is injected rapidly and blood pressure is recorded immediately after injection, at 30-second intervals for the first 3 minutes, and at 60-second intervals for the next 7 minutes. A positive response to the reginitine blocking test is present when the blood pressure is reduced more than 35 mmHg systolic and 25 mmHg diastolic. A typical positive response is a reduction in pressure of 60 mmHg systolic and 25 mmHg diastolic. A positive response is suggestive of pheochromocytoma and should generally be confirmed by other diagnostic procedures such as measurement of urinary catecholamines or their metabolites.

Rare diseases that can present with this3

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category