INDICATIONS AND USAGE Phentolamine Mesylate for Injection, USP is indicated for the prevention or control of hypertensive episodes that may occur in a patient with pheochromocytoma as a result of stress or manipulation during preoperative preparation and surgical excision.

Phentolamine Mesylate for Injection, USP is indicated for the prevention or treatment of dermal necrosis and sloughing following intravenous administration or extravasation of norepinephrine.

Phentolamine Mesylate for Injection, USP is also indicated for the diagnosis of pheochromocytoma by the Phentolamine Mesylate for Injection, USP blocking test.

WARNINGS Myocardial infarction, cerebrovascular spasm, and cerebrovascular occlusion have been reported to occur following the administration of Phentolamine Mesylate for Injection, USP, usually in association with marked hypotensive episodes.

For screening tests in patients with hypertension, the generally available urinary assay of catecholamines or other biochemical assays have largely replaced the Phentolamine Mesylate for Injection, USP and other pharmacological tests for reasons of accuracy and safety.

None of the chemical or pharmacological tests is infallible in the diagnosis of pheochromocytoma.

The Phentolamine Mesylate for Injection, USP blocking test is not the procedure of choice and should be reserved for cases in which additional confirmatory evidence is necessary and the relative risks involved in conducting the test have been considered.

ADVERSE REACTIONS Acute and prolonged hypotensive episodes, tachycardia, and cardiac arrhythmias have been reported.

In addition, weakness, dizziness, flushing, orthostatic hypotension, nasal stuffiness, nausea, vomiting, and diarrhea may occur.

To report SUSPECTED ADVERSE REACTIONS, contact Precision Dose Inc.

at 1-844-668-3942 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.