Phenoxybenzamine

Pronunciation: fen-OX-ee-BEN-za-meen
Generic Name: Phenoxybenzamine
Brand Name: Dibenzyline

Phenoxybenzamine is used for:

Treating high blood pressure and sweating caused by a certain kind of tumor (pheochromocytoma). It may also be used for other conditions as determined by your doctor.

Phenoxybenzamine is an alpha-blocker. It works by relaxing blood vessels, causing blood pressure to decrease.

Do NOT use Phenoxybenzamine if:

• you are allergic to any ingredient in Phenoxybenzamine


• you have a condition in which a fall in blood pressure may be undesirable

Contact your doctor or health care provider right away if any of these apply to you.

Before using Phenoxybenzamine:

Some medical conditions may interact with Phenoxybenzamine. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding


• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement


• if you have allergies to medicines, foods, or other substances


• if you have problems with the blood vessels of the heart or brain, heart problems, an irregular heartbeat, a lung or respiratory tract infection, or kidney problems


• if you have a history of cancer


• if you are taking any other medicine for blood pressure

Some MEDICINES MAY INTERACT with Phenoxybenzamine. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Epinephrine because severe low blood pressure may occur


• Levarterenol or reserpine because their effectiveness may be decreased by Phenoxybenzamine

This may not be a complete list of all interactions that may occur. Ask your health care provider if Phenoxybenzamine may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use Phenoxybenzamine:

Use Phenoxybenzamine as directed by your doctor. Check the label on the medicine for exact dosing instructions.

• Take Phenoxybenzamine by mouth with or without food.


• Take Phenoxybenzamine on a regular schedule to get the most benefit from it.


• If you miss a dose of Phenoxybenzamine, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Ask your health care provider any questions you may have about how to use Phenoxybenzamine.

Important safety information:

• Phenoxybenzamine may cause drowsiness or dizziness. These effects may be worse if you take it with alcohol or certain medicines. Use Phenoxybenzamine with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.


• Phenoxybenzamine may cause dizziness, lightheadedness, or fainting; alcohol, hot weather, exercise, or fever may increase these effects. To prevent them, sit up or stand slowly, especially in the morning. Sit or lie down at the first sign of any of these effects.


• Patients who take medicine for high blood pressure often feel tired or run down for a few weeks after starting treatment. Be sure to take your medicine even if you may not feel "normal." Tell your doctor if you develop any new symptoms.


• Do NOT take more than the recommended dose or use for longer than prescribed without checking with your doctor.


• Phenoxybenzamine may increase your risk of developing certain types of cancer if taken for a long period of time. Long-term use of Phenoxybenzamine is not recommended.


• Tell your doctor or dentist that you take Phenoxybenzamine before you receive any medical or dental care, emergency care, or surgery.


• Lab tests, including blood pressure checks, may be performed while you use Phenoxybenzamine. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.


• Use Phenoxybenzamine with caution in the ELDERLY; they may be more sensitive to its effects, especially dizziness.


• Phenoxybenzamine should be used with extreme caution in CHILDREN; safety and effectiveness in children have not been confirmed.


• PREGNANCY and BREAST-FEEDING: Phenoxybenzamine may cause harm to the fetus. Do not become pregnant while you are using it. If you think you may be pregnant, contact your doctor. You will need to discuss the benefits and risks of using Phenoxybenzamine while you are pregnant. It is not known if Phenoxybenzamine is found in breast milk. Do not breast-feed while taking Phenoxybenzamine.

Possible side effects of Phenoxybenzamine:

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Dizziness; drowsiness; nasal congestion; stomach upset; tiredness.

Seek medical attention right away if any of these SEVERE side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); change in sexual function; fainting; fast heartbeat; new or unusual lumps or growths; pinpoint pupils; severe dizziness or lightheadedness when sitting or standing; vomiting.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.

See also: Phenoxybenzamine side effects (in more detail)

If OVERDOSE is suspected:

Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center, or emergency room immediately. Symptoms may include fainting; fast heartbeat; severe dizziness, lightheadedness, or fainting, especially when sitting or standing; severe tiredness or weakness; vomiting.

Proper storage of Phenoxybenzamine:

Store Phenoxybenzamine at 77 degrees F (25 degrees C). Brief storage at temperatures between 59 and 86 degrees F (15 and 30 degrees C) is permitted. Store away from heat, moisture, and light. Do not store in the bathroom. Keep Phenoxybenzamine out of the reach of children and away from pets.

General information:

• If you have any questions about Phenoxybenzamine, please talk with your doctor, pharmacist, or other health care provider.


• Phenoxybenzamine is to be used only by the patient for whom it is prescribed. Do not share it with other people.


• If your symptoms do not improve or if they become worse, check with your doctor.


• Check with your pharmacist about how to dispose of unused medicine.

This information is a summary only. It does not contain all information about Phenoxybenzamine. If you have questions about the medicine you are taking or would like more information, check with your doctor, pharmacist, or other health care provider.

Issue Date: February 1, 2012

Database Edition 12.1.1.002

Copyright © 2012 Wolters Kluwer Health, Inc.

More Phenoxybenzamine resources

• Phenoxybenzamine Side Effects (in more detail)
• Phenoxybenzamine Use in Pregnancy & Breastfeeding
• Phenoxybenzamine Drug Interactions
• Phenoxybenzamine Support Group
• 0 Reviews for Phenoxybenzamine - Add your own review/rating

• phenoxybenzamine Concise Consumer Information (Cerner Multum)


• phenoxybenzamine Advanced Consumer (Micromedex) - Includes Dosage Information


• Dibenzyline Prescribing Information (FDA)


• Dibenzyline Monograph (AHFS DI)

Compare Phenoxybenzamine with other medications

• Pheochromocytoma