What do you feel about the cost of the medicine? Is it expensive?

Phentolamine uses

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

Phentolamine, USP is 4,5-dihydro-2-[N-(m-hydroxyphenyl)-N-(p-methylphenyl) amino methyl]-1H- imidazole 1:1 methanesulfonate, and its structural formula is

Phentolamine, USP is a white or off-white, odorless crystalline powder with a molecular weight of 377.46. 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 for Injection, USP 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 for Injection, USP 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 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 for Injection, USP is indicated for the prevention or treatment of dermal necrosis and sloughing following intravenous administration or extravasation of norepinephrine.

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



Tachycardia and cardiac arrhythmias may occur with the use of Phentolamine for Injection, USP or other alpha-adrenergic blocking agents. When possible, administration of cardiac glycosides should be deferred until cardiac rhythm returns to normal.

Drug Interactions

See DOSAGE AND ADMINISTRATION, Diagnosis of pheochromocytoma, Preparation .

Carcinogenesis, Mutagenesis, Impairment of Fertility

Long-term carcinogenicity studies, mutagenicity studies, and fertility studies have not been conducted with Phentolamine for Injection, USP.

Pregnancy Category C

Administration of Phentolamine for Injection, USP to pregnant rats and mice at oral doses 24-30 times the usual daily human dose resulted in slightly decreased growth and slight skeletal immaturity of the fetuses. Immaturity was manifested by increased incidence of incomplete or unossified calcanei and phalangeal nuclei of the hind limb and of incompletely ossified sternebrae. At oral doses 60 times the usual daily human dose (based on a 60-kg human), a slightly lower rate of implantation was found in the rat. Phentolamine for Injection, USP did not affect embryonic or fetal development in the rabbit at oral doses 20 times the usual daily human dose (based on a 60-kg human). No teratogenic or embryo toxic effects were observed in the rat, mouse, or rabbit studies.

There are no adequate and well-controlled studies in pregnant women. Phentolamine for Injection, USP should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Nursing Mothers

It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from Phentolamine for Injection, USP, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

Pediatric Use




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


Acute Toxicity

No deaths due to acute poisoning with Phentolamine for Injection, USP have been reported.

Oral LD50’s : mice, 1000; rats, 1250.

Signs and Symptoms

Overdosage with Phentolamine for Injection, USP is characterized chiefly by cardiovascular disturbances, such as arrhythmias, tachycardia, hypotension, and possibly shock. In addition, the following might occur: excitation, headache, sweating, pupillary contraction, visual disturbances; nausea, vomiting, diarrhea; hypoglycemia.


There is no specific antidote.

A decrease in blood pressure to dangerous levels or other evidence of shock like conditions should be treated vigorously and promptly. The patient’s legs should be kept raised and a plasma expander should be administered. If necessary, intravenous infusion of norepinephrine, titrated to maintain blood pressure at the normotensive level, and all available supportive measures should be included. Epinephrine should not be used, since it may cause a paradoxical reduction in blood pressure.



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

Note: Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

1. Prevention or control of hypertensive episodes in the patient with pheochromocytoma.

For preoperative reduction of elevated blood pressure, 5 mg of Phentolamine for Injection, USP is injected intravenously or intramuscularly 1 or 2 hours before surgery, and repeated if necessary.

During surgery, Phentolamine for Injection, USP (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 for Injection, USP is added to each liter of solution containing norepinephrine. The pressor effect of norepinephrine is not affected.

For Treatment: 5-10 mg of Phentolamine for Injection, USP in 10 mL of saline is injected into the area of extravasation within 12 hours.

3. Diagnosis of pheochromocytoma - Phentolamine for Injection, USP 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.

a. Intravenous


The CONTRAINDICATIONS, WARNINGS, and PRECAUTIONS sections should be reviewed. Sedatives, analgesics, and all other medications except those that might be deemed essential are withheld for at least 24 hours, and preferably 48 -72 hours, prior to the test. Antihypertensive drugs are withheld until blood pressure returns to the untreated, hypertensive level. This test is not performed on a patient who is normotensive.


The patient is kept at rest in the supine position throughout the test, preferably in a quiet, darkened room. Injection of Phentolamine for Injection, USP is delayed until blood pressure is stabilized, as evidenced by blood pressure readings taken every 10 minutes for at least 30 minutes.

Five milligrams of Phentolamine for Injection, USP is dissolved in 1mL of Sterile Water for Injection. The dose for adults is 5 mg; for children, 1 mg.

The syringe needle is inserted into the vein, and injection is delayed until pressor response to venipuncture has subsided.

Phentolamine for Injection, USP is injected rapidly. 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, suggestive of pheochromocytoma, is indicated 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. Usually, maximal effect is evident within 2 minutes after injection. A return to preinjection pressure commonly occurs within 15-30 minutes but may occur more rapidly.

If blood pressure decreases to a dangerous level, the patient should be treated as outlined under OVERDOSAGE.

A positive response should always be confirmed by other diagnostic procedures, preferably by measurement of urinary catecholamines or their metabolites.

A negative response is indicated when the blood pressure is elevated, unchanged, or reduced less than 35 mmHg, systolic and 25 mmHg diastolic after injection of Phentolamine for Injection, USP. A negative response to this test does not exclude the diagnosis of pheochromocytoma, especially in patients with paroxysmal hypertension in whom the incidence of false-negative responses is high.

b. Intramuscular

If the intramuscular test for pheochromocytoma is preferred, preparation is the same as for the intravenous test. Five milligrams of Phentolamine for Injection, USP is then dissolved in 1mL of Sterile Water for Injection. The dose for adults is 5 mg intramuscularly; for children, 3 mg. Blood pressure is recorded every 5 minutes for 30-45 minutes following injection. A positive response is indicated when the blood pressure is reduced 35 mmHg systolic and 25 mmHg diastolic, or more, within 20 minutes following injection.



Vials-each containing 5 mg of Phentolamine, USP, and 25 mg of mannitol, USP, in sterile, lyophilized form.

Cartons of 1…………………………………………………………….NDC 68094-101-20

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

Store at 20˚ to 25˚ C (68° - 77˚ F) with excursions between 15˚ to 30˚ C (59˚ to 86˚ F) [USP controlled Room Temperature]

You can also call Precision Dose Inc. at 1-800-397-9228 or visit

Distributed by

Precision Dose, Inc.

South Beloit, IL 61080

Revised: 07/2017

Phentolamine pharmaceutical active ingredients containing related brand and generic drugs:

Active ingredient is the part of the drug or medicine which is biologically active. This portion of the drug is responsible for the main action of the drug which is intended to cure or reduce the symptom or disease. The other portions of the drug which are inactive are called excipients; there role is to act as vehicle or binder. In contrast to active ingredient, the inactive ingredient's role is not significant in the cure or treatment of the disease. There can be one or more active ingredients in a drug.

Phentolamine available forms, composition, doses:

Form of the medicine is the form in which the medicine is marketed in the market, for example, a medicine X can be in the form of capsule or the form of chewable tablet or the form of tablet. Sometimes same medicine can be available as injection form. Each medicine cannot be in all forms but can be marketed in 1, 2, or 3 forms which the pharmaceutical company decided based on various background research results.
Composition is the list of ingredients which combinedly form a medicine. Both active ingredients and inactive ingredients form the composition. The active ingredient gives the desired therapeutic effect whereas the inactive ingredient helps in making the medicine stable.
Doses are various strengths of the medicine like 10mg, 20mg, 30mg and so on. Each medicine comes in various doses which is decided by the manufacturer, that is, pharmaceutical company. The dose is decided on the severity of the symptom or disease.

Injectable; Injection; Phentolamine Mesylate 5 mg
Injectable; Injection; Phentolamine Mesylate 5 mg / ml
Phentolamine 5 mg vial84.0 USD

Phentolamine destination | category:

Destination is defined as the organism to which the drug or medicine is targeted. For most of the drugs what we discuss, human is the drug destination.
Drug category can be defined as major classification of the drug. For example, an antihistaminic or an antipyretic or anti anginal or pain killer, anti-inflammatory or so.

Phentolamine Anatomical Therapeutic Chemical codes:

A medicine is classified depending on the organ or system it acts [Anatomical], based on what result it gives on what disease, symptom [Therapeutical], based on chemical composition [Chemical]. It is called as ATC code. The code is based on Active ingredients of the medicine. A medicine can have different codes as sometimes it acts on different organs for different indications. Same way, different brands with same active ingredients and same indications can have same ATC code.

Phentolamine pharmaceutical companies:

Pharmaceutical companies are drug manufacturing companies that help in complete development of the drug from the background research to formation, clinical trials, release of the drug into the market and marketing of the drug.
Researchers are the persons who are responsible for the scientific research and is responsible for all the background clinical trials that resulted in the development of the drug.



  1. Dailymed."PHENTOLAMINE MESYLATE INJECTION [PRECISION DOSE INC.]". (accessed August 28, 2018).
  2. "phentolamine". (accessed August 28, 2018).
  3. "phentolamine". (accessed August 28, 2018).

Frequently asked Questions

Can i drive or operate heavy machine after consuming Phentolamine?

Depending on the reaction of the Phentolamine after taken, if you are feeling dizziness, drowsiness or any weakness as a reaction on your body, Then consider Phentolamine not safe to drive or operate heavy machine after consumption. Meaning that, do not drive or operate heavy duty machines after taking the capsule if the capsule has a strange reaction on your body like dizziness, drowsiness. As prescribed by a pharmacist, it is dangerous to take alcohol while taking medicines as it exposed patients to drowsiness and health risk. Please take note of such effect most especially when taking Primosa capsule. It's advisable to consult your doctor on time for a proper recommendation and medical consultations.

Is Phentolamine addictive or habit forming?

Medicines are not designed with the mind of creating an addiction or abuse on the health of the users. Addictive Medicine is categorically called Controlled substances by the government. For instance, Schedule H or X in India and schedule II-V in the US are controlled substances.

Please consult the medicine instruction manual on how to use and ensure it is not a controlled substance.In conclusion, self medication is a killer to your health. Consult your doctor for a proper prescription, recommendation, and guidiance.


Review conducted a study on Phentolamine, and the result of the survey is set out below. It is noteworthy that the product of the survey is based on the perception and impressions of the visitors of the website as well as the views of Phentolamine consumers. We, as a result of this, advice that you do not base your therapeutic or medical decisions on this result, but rather consult your certified medical experts for their recommendations.

Visitor reports

Visitor reported useful

No survey data has been collected yet

Visitor reported side effects

No survey data has been collected yet

Visitor reported price estimates

No survey data has been collected yet

Visitor reported frequency of use

No survey data has been collected yet

Visitor reported doses

No survey data has been collected yet

Visitor reported time for results

No survey data has been collected yet

Visitor reported administration

No survey data has been collected yet

Visitor reported age

No survey data has been collected yet

Visitor reviews

There are no reviews yet. Be the first to write one!

Your name: 
Spam protection:  < Type 22 here

The information was verified by Dr. Rachana Salvi, MD Pharmacology

© 2002 - 2024 "". All Rights Reserved