Phenoxybenzamine

Generic name: phenoxybenzamine
Brand name: Dibenzyline
Dosage form: oral capsule (10 mg)
Drug class: Miscellaneous cardiovascular agents

Medically reviewed by A Ras MD.

What is phenoxybenzamine used for?

Phenoxybenzamine is a prescription medicine that is used to treat pheochromocytoma.

Description

Each phenoxybenzamine hydrochloride capsule, USP with red cap and body, is imprinted with “Amneal” on cap and “1502” on body, and contains 10 mg of phenoxybenzamine hydrochloride, USP. Inactive ingredients consist of colloidal silicon dioxide, D&C red 33, FD & C red 3, gelatin, iron oxide yellow, lactose monohydrate and sodium lauryl sulfate.

The capsule is imprinted with white pharmaceutical ink which contains butyl alcohol, dehydrated alcohol, isopropyl alcohol, potassium hydroxide, propylene glycol, shellac, strong ammonia solution and titanium dioxide.

Phenoxybenzamine hydrochloride is chemically known as N-(2-Chloroethyl)-N-(1-methyl-2-phenoxyethyl) benzylamine hydrochloride. Its molecular formula is C18H22ClNO·HCl.

The chemical structure is:

Phenoxybenzamine hydrochloride, USP is a white to almost white crystalline powder with a molecular weight of 340.29 g/mol, which melts between 136° and 141°C. It is freely soluble in ethanol (96%) and insoluble in diethyl ether.

Before taking phenoxybenzamine, tell your doctor:

If you are allergic to phenoxybenzamine; any part of this medicine; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
If you are breast-feeding or plan to breast-feed.

This medicine may interact with other drugs or health problems.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take phenoxybenzamine with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take phenoxybenzamine?

Tell all of your health care providers that you take phenoxybenzamine. This includes your doctors, nurses, pharmacists, and dentists.
Avoid driving and doing other tasks or actions that call for you to be alert until you see how phenoxybenzamine affects you.
To lower the chance of feeling dizzy or passing out, rise slowly if you have been sitting or lying down. Be careful going up and down stairs.
Check blood pressure and heart rate as the doctor has told you.
Do not take phenoxybenzamine for longer than you were told by your doctor.
Tell your doctor if you are pregnant or plan on getting pregnant. You will need to talk about the benefits and risks of using phenoxybenzamine while you are pregnant.

How is phenoxybenzamine best taken?

Use phenoxybenzamine as ordered by your doctor. Read all information given to you. Follow all instructions closely.

Take with or without food.

What do I do if I miss a dose?

Take a missed dose as soon as you think about it.
If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
Do not take 2 doses at the same time or extra doses.

What are the side effects of phenoxybenzamine that I need to call my doctor about immediately?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
Very bad dizziness or passing out.
A fast heartbeat.
Small pupils.
Ejaculation problems.

What are some other side effects of phenoxybenzamine?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

Feeling sleepy.
Stuffy nose.
Upset stomach.
Feeling tired or weak.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

If overdose is suspected:

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

How do I store and/or throw out phenoxybenzamine?

Store at room temperature.
Store in a dry place. Do not store in a bathroom.
Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.