PHENTOLAMINE MESYLATE FOR INJECTION, USP

Rx ONLY

Phentolamine Mesylate for Injection, USP, is an antihypertensive, available in vials for intravenous and intramuscular administration. Each vial contains phentolamine mesylate USP, 5 mg and mannitol USP, 25 mg in sterile, lyophilized form.

Phentolamine mesylate is m-[N-(2-Imidazolin-2-ylmethyl)-p-toluidino]phenol monomethanesulfonate (salt), and its structural formula is:

    structural formula

                                                                               Molecular Formula  C₁₇H₁₉N₃O•CH₄O₃S                                 

                                                                                                   M.W.  377.47

Phentolamine mesylate, USP is a white or off-white, odorless crystalline powder. Its solutions are acid to litmus. It is freely soluble in water and in alcohol, and slightly soluble in chloroform. It melts at about 178°C.

Phentolamine mesylate produces an alpha-adrenergic block of relatively short duration. It also has direct, but less marked, positive inotropic and chronotropic effects on cardiac muscle and vasodilator effects on vascular smooth muscle.

Phentolamine has a half-life in the blood of 19 minutes following intravenous administration. Approximately 13% of a single intravenous dose appears in the urine as unchanged drug.

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

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

Myocardial infarction, history of myocardial infarction, coronary insufficiency, angina, or other evidence suggestive of coronary artery disease; hypersensitivity to phentolamine or related compounds.

Myocardial infarction, cerebrovascular spasm, and cerebrovascular occlusion have been reported to occur following the administration of phentolamine, 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 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 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.

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.

The reconstituted solution should be used upon preparation and should not be stored.

• 1.Prevention or control of hypertensive episodes in the patient with pheochromo-cytoma. For preoperative reduction of elevated blood pressure, 5 mg of phentolamine mesylate (1 mg for children) is injected intravenously or intramuscularly 1 or 2 hours before surgery, and repeated if necessary.
  During surgery, phentolamine mesylate (5 mg for adults, 1 mg for children) is administered intravenously as indicated, to help prevent or control paroxysms of hypertension, tachycardia, respiratory depression, convulsions, or other effects of epinephrine intoxication. (Postoperatively, norepinephrine may be given to control the hypotension that commonly follows complete removal of a pheochromocytoma.)
• 2.Prevention or treatment of dermal necrosis and sloughing following intravenous administration or extravasation of norepinephrine.
  For Prevention: 10 mg of phentolamine mesylate is added to each liter of solution containing norepinephrine. The pressor effect of norepinephrine is not affected.
  For Treatment: 5 to 10 mg of phentolamine mesylate in 10 mL of saline is injected into the area of extravasation within 12 hours.
• 3.Diagnosis of pheochromocytoma - phentolamine blocking test.
  The test is most reliable in detecting pheochromocytoma in patients with sustained hypertension and least reliable in those with paroxysmal hypertension. False-positive tests may occur in patients with hypertension without pheochromocytoma.

Phentolamine Mesylate for Injection, USP, 5 mg, for intramuscular or intravenous use, is supplied as follows:

NDC 0143-9564-01 - 2 mL vials packaged individually.

NDC 0143-9564-10 - 2 mL vials packaged in cartons of 10 vials.

The reconstituted solution should be used upon preparation and should not be stored.

Store at 20° to 25° C (68° to 77° F) [See USP Controlled Room Temperature].

To report SUSPECTED ADVERSE REACTIONS, contact Hikma Pharmaceuticals USA Inc. at 1-877-845-0689, or the FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

For Product Inquiry call 1-877-845-0689.

Manufactured by:

HIKMA FARMACÊUTICA (PORTUGAL), S.A.

Estrada do Rio da Mó, 8, 8A e 8B – Fervença – 2705-906 Terrugem SNT, PORTUGAL

Distributed by:

Hikma Pharmaceuticals USA Inc.

Berkeley Heights, NJ 07922

Revised May 2022

PIN385-WES/5

NDC 0143-9564-01    Rx only 

Phentolamine Mesylate for Injection, USP
5 mg per vial
For IM or IV Use
LYOPHILIZED 

  5 mg vial

NDC 0143-9564-01    Rx only 

Phentolamine Mesylate for Injection, USP
5 mg per vial
For IM or IV Use
LYOPHILIZED

1 x 2 mL Vial

NDC 0143-9564-10    Rx only 

Phentolamine Mesylate for Injection, USP
5 mg/vial
For IM or IV Use 
LYOPHILIZED

10 x 2 mL Vials

Representative Carton Serialization Image