Quick answers
- What is Phentolamine mesylate used for?
- The FDA-approved label (Phentolamine Mesylate, Precision Dose Inc., August 19, 2024) says: “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. …” This page is not medical advice. Talk to your doctor or pharmacist before you start, stop or change any medicine.
- What are the side effects of Phentolamine mesylate?
- The “Adverse Reactions” section of the FDA label (Phentolamine Mesylate, Precision Dose Inc., August 19, 2024) begins: “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.” This page is not medical advice. Talk to your doctor or pharmacist before you start, stop or change any medicine.
- What are the drug interactions of Phentolamine mesylate?
- The “Drug Interactions” section of the FDA label (Phentolamine Mesylate, Precision Dose Inc., August 19, 2024) begins: “See DOSAGE AND ADMINISTRATION, Diagnosis of pheochromocytoma, Preparation.” This page is not medical advice. Talk to your doctor or pharmacist before you start, stop or change any medicine.
- Does Phentolamine mesylate have a boxed warning?
- No. None of the 3 FDA labels we found for this medicine has a boxed warning.
- Is there a shortage of Phentolamine mesylate?
- No current shortage is listed by the FDA for the products of this medicine (FDA data from October 30, 2026).
- Has Phentolamine mesylate been recalled?
- FDA enforcement reports list 2 recalls of products of this medicine; the newest started October 31, 2025 (Class II). A recall usually concerns specific lots, not every product.
- Who makes Phentolamine mesylate?
- 4 companies list prescription products of Phentolamine mesylate in the FDA NDC Directory, including Septodont, Inc., Oyster Point Pharma, Inc. and Precision Dose, Inc.
What Phentolamine mesylate is used for
Quoted from the “Indications and Usage” section of the FDA-approved label.
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. …
— FDA label: Phentolamine Mesylate, Precision Dose Inc., effective August 19, 2024. Read the full label on DailyMed →
Label quoted: the one for the most common form (injection, intramuscular), Phentolamine Mesylate, Precision Dose Inc.; it covers 1 product in the FDA NDC Directory. The side effects, interactions, dosage and pregnancy quotes below come from this same label.
The FDA has 3 labels for products of this medicine (different makers and forms); uses can differ between them. Check the label that comes with your own medicine.
This page is not medical advice. Talk to your doctor or pharmacist before you start, stop or change any medicine.
Boxed warning
A boxed warning (“black box”) is the FDA’s strongest warning on a drug label, for serious or life-threatening risks.
The label quoted above has no boxed warning.
0 of 3 FDA labels for this medicine have a boxed warning.
Phentolamine mesylate side effects
Quoted from the “Adverse Reactions” section of the FDA-approved label. Tell your doctor about any side effect that worries you.
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.
— FDA label: Phentolamine Mesylate, Precision Dose Inc., effective August 19, 2024. Read the full label on DailyMed →
Phentolamine mesylate drug interactions
Quoted from the “Drug Interactions” section of the FDA-approved label. Tell your pharmacist about every medicine, vitamin and herbal product you take.
See DOSAGE AND ADMINISTRATION, Diagnosis of pheochromocytoma, Preparation.
— FDA label: Phentolamine Mesylate, Precision Dose Inc., effective August 19, 2024. Read the full label on DailyMed →
Phentolamine mesylate dosage
Quoted from the “Dosage and Administration” section of the FDA-approved label. Your own dose is the one your doctor prescribes: do not change it on your own.
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.
Read more of this section
For preoperative reduction of elevated blood pressure, 5 mg of Phentolamine Mesylate for Injection, USP (1mg for children) is injected intravenously or intramuscularly 1 or 2 hours before surgery, and repeated if necessary. During surgery, Phentolamine Mesylate 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 Mesylate 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 Mesylate for Injection, USP in 10 mL of saline is injected into the area of extravasation within 12 hours. 3. Diagnosis of pheochromocytoma — Phentolamine Mesylate 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 Preparation The CONTRAINDICATIONS, WARNINGS, and PRECAUTIONS sections should be reviewed. Sedatives, analgesics, and all other medications except those that might be deemed essential (such as digitalis and insulin) 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. Procedure The patient is kept at rest in the supine position throughout the test, preferably in a quiet, darkened room. Injection of Phentolamine Mesylate 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 Mesylate 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 Mesylate 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.
— FDA label: Phentolamine Mesylate, Precision Dose Inc., effective August 19, 2024. This is part of the section. Read the full label on DailyMed →
Phentolamine mesylate in pregnancy
Quoted from the pregnancy part of the FDA-approved label. Ask your doctor before you take any medicine while pregnant or planning a pregnancy.
Category C Administration of Phentolamine Mesylate for Injection, USP to pregnant rats and mice at oral doses 24-30 times the usual daily human dose (based on a 60-kg human) 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.
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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 Mesylate 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 Mesylate for Injection, USP should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
— FDA label: Phentolamine Mesylate, Precision Dose Inc., effective August 19, 2024. Read the full label on DailyMed →
Phentolamine mesylate and breastfeeding
Quoted from the nursing mothers / lactation part of the FDA-approved label.
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 Mesylate 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 See DOSAGE AND ADMINISTRATION
— FDA label: Phentolamine Mesylate, Precision Dose Inc., effective August 19, 2024. Read the full label on DailyMed →
When Phentolamine mesylate should not be used
Quoted from the “Contraindications” section of the FDA-approved label.
Myocardial infarction, history of myocardial infarction, coronary insufficiency, angina or other evidence suggestive of coronary artery disease; hypersensitivity to phentolamine or related compounds.
— FDA label: Phentolamine Mesylate, Precision Dose Inc., effective August 19, 2024. Read the full label on DailyMed →
Phentolamine mesylate overdose
Quoted from the “Overdosage” section of the FDA-approved label. If someone may have taken too much, call Poison Help at 1-800-222-1222 (or 911 in an emergency).
Acute Toxicity No deaths due to acute poisoning with Phentolamine Mesylate for Injection, USP have been reported. Oral LD 50 's (mg/kg): mice, 1000; rats, 1250. Signs and Symptoms Overdosage with Phentolamine Mesylate for Injection, USP is characterized chiefly by cardiovascular disturbances, such as arrhythmias, tachycardia, hypotension, and possibly shock.
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In addition, the following might occur: excitation, headache, sweating, pupillary contraction, visual disturbances; nausea, vomiting, diarrhea; hypoglycemia. Treatment 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. Acute Toxicity No deaths due to acute poisoning with Phentolamine Mesylate for Injection, USP have been reported. Oral LD 50 's (mg/kg): mice, 1000; rats, 1250. Signs and Symptoms Overdosage with Phentolamine Mesylate 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. Treatment 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.
— FDA label: Phentolamine Mesylate, Precision Dose Inc., effective August 19, 2024. Read the full label on DailyMed →
Forms and how it is given
Companies that list this medicine
Labelers in the FDA NDC Directory: the company named on the package (maker or distributor), with the number of prescription products.
- Septodont, Inc.1 product
- Oyster Point Pharma, Inc.1 product
- Precision Dose, Inc.1 product
- Hikma Pharmaceuticals USA Inc.1 product
FDA approval history
- NDA: New Drug Application: how a new (usually brand-name) medicine is approved.
- ANDA: Abbreviated New Drug Application: how a generic version is approved.
| Application | Sponsor | Approved | Later changes approved |
|---|---|---|---|
| NDA022159 ORAVERSE | Septodont Holding | May 9, 2008 | 8, latest March 18, 2016 2016: Efficacy · 2016: Manufacturing (CMC) · 2015: Manufacturing (CMC) |
| NDA217064 RYZUMVI | Famygen Life Sci | September 25, 2023 | 3, latest October 16, 2026 2026: Efficacy · 2026: Manufacturing (CMC) · 2023: Labeling |
Generic approvals (2)
- ANDA040235Hikma · March 11, 1998
- ANDA207686Precision Dose Inc · July 14, 2017
Shortage status
The FDA drug shortage list does not show these products.
Recalls
From FDA enforcement reports, matched by the product’s NDC code. A recall usually covers specific lots only: check the lot number on your package and ask your pharmacist. Do not stop a medicine on your own.
-
October 31, 2025 · Class II · Ongoing · D-0234-2026
Defective container: cracked/broken cartridges
OraVerse, (Phentolamine Mesylate) Injection, 0.4 mg/1.7mL, packaged in a carton containing 10 cartridges, 0.4 mg/1.7mL, Rx only, Made in Canada by Novocol Pharmaceutical of Canada, Inc., Distributed by Septodont, Inc., L — Novocol Pharmaceutical of Canada, Inc.
-
April 13, 2018 · Class III · Terminated · D-0828-2018
Failed Impurities/Degradation: This recall has been initiated due to an out of specification (OOS) result that was obtained for related substance (Phentolamide), a known degradation product impurity at the 15 month stability test point.
OraVerse (Phentolamine Mesylate) Injection, 0.4 mg/1.7mL, packaged in a box of 10 cartridges of 0.4mg/1.7mL each, Rx only, Distributed by Septodont, Inc., Louisville, CO 80027, Made in Canada by Novocol Pharmaceutical of — Septodont Inc.
What do the recall classes mean?
Class I: The most serious type: there is a reasonable chance that using the product will cause serious health problems or death.
Class II: Using the product may cause temporary or medically reversible health problems, or the chance of serious problems is remote.
Class III: Using the product is not likely to cause health problems (for example a labeling or packaging issue).
Official identifiers
| RxCUI (RxNorm) | 1361019, 1361021, 1361023 |
|---|---|
| SPL set ID of the quoted label | e146c7ee-d2fa-433c-8768-0945e4ff0990 |
| FDA labels (SPL) | 3 |
| FDA applications | NDA022159, NDA217064, 2 ANDA |
| Active ingredients (FDA) | PHENTOLAMINE |
Next steps
- Find a pharmacy near youAsk which price applies to you and whether your product is affected by a recall
- Latest FDA drug recallsAll medicines, newest first
- OraverseBrand page: products, maker and price
- RyzumviBrand page: products, maker and price
- Septodont, Inc.Maker or distributor
- Oyster Point Pharma, Inc.Maker or distributor
- Precision Dose, Inc.Maker or distributor
- All prescription drugs A to ZSearch by generic, brand or Spanish name
Sources
- FDA-approved label on DailyMed (National Library of Medicine) — Phentolamine Mesylate, Precision Dose Inc., effective August 19, 2024; via openFDA, FDA data exported October 30, 2026, retrieved October 31, 2026
- NDC Directory (openFDA) — U.S. Food and Drug Administration (FDA), FDA data exported October 30, 2026, retrieved October 31, 2026
- Drugs@FDA (openFDA) — U.S. Food and Drug Administration (FDA), FDA data exported October 30, 2026, retrieved October 31, 2026
- Drug recall enforcement reports (openFDA) — U.S. Food and Drug Administration (FDA), FDA data exported October 27, 2026, retrieved October 31, 2026
- Drug shortages (openFDA) — U.S. Food and Drug Administration (FDA), FDA data exported October 30, 2026, retrieved October 31, 2026
openFDA data is provided by the FDA as is; it may be incomplete. Always rely on the label that comes with your medicine. FDA Enforcement Report search →