Indication
Assist in the diagnosis of Pheochromocytoma.

Preparation
Do not take antihypertensive medication the morning of the test.

Procedure
1. Obtain baseline blood pressure.
2. Leave patient to lie supine in a dark room for 30 minutes.
3. Draw baseline catecholamines, specimen to be kept on ice and sent to laboratory immediately.
4. Administer clonidine 0.3 mg by mouth.
5. Leave patient to rest in a darkened room supine for the remainder of suppression test.
6. Monitor and record blood pressure every 15 minutes for 1 hour. Continue to monitor blood pressure every 30 minutes for two hours.
7. Serum catecholamines at 3 hours.

 Precautions
Keep 1000 cc of normal saline nearby and administer if patient becomes hypotensive.
Contact physician immediately if blood pressure decreases significantly from baseline.

Interpretation
If patient has a pheochromocytoma, the serum catecholamines will not suppress to clonidine.