Phenoxybenzamine

Phenoxybenzamine is used to manage blood pressure and decrease sweating in individuals with pheochromocytoma (a tumor of the adrenal gland).

Phenoxybenzamine may also be used for reasons not mentioned in this medication guide.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

Call your doctor if you have fast heartbeats. You may need to be treated with an additional medication.

Store phenoxybenzamine at room temperature away from moisture and heat.

Follow all instructions on your medicine label and package. Inform each of your healthcare providers about all your medical conditions, allergies, and all medicines you are taking.

You should not use phenoxybenzamine if you are allergic to it.

Tell your doctor if you have ever had:

• coronary artery disease (hardened arteries);
• a lung infection; or
• kidney disease.

Tell your doctor if you are pregnant.

You should not breastfeed while using phenoxybenzamine.

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using phenoxybenzamine and call your doctor immediately if you have severe dizziness or if you feel like you might faint.

Common side effects of phenoxybenzamine may include:

• stuffy nose;
• mild dizziness or drowsiness;
• blurred vision;
• trouble having an orgasm;
• upset stomach; or
• feeling tired.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Usual Adult Dose for Pheochromocytoma:

Initial dose: 10 mg orally twice dailyMaintenance dose: 20 to 40 mg orally 2 to 3 times daily until an optimal dosage (as judged by blood pressure control) is obtained.

Take the medicine as soon as you can, but skip the missed dose if it is nearly time for your next dose. Do not take two doses at the same time.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include fast heart rate, vomiting, dizziness, or fainting.

Avoid driving or hazardous activity until you know how phenoxybenzamine will affect you. Your reactions could be impaired.

Avoid getting up too fast from a sitting or lying position, or you may feel dizzy.

Drinking alcohol with this medicine can cause side effects.

Tell your doctor about all your other medicines, especially:

• reserpine;
• tizanidine;
• epinephrine (Epi-Pen), norepinephrine; or
• blood pressure medications.

This list is not complete. Other drugs may affect phenoxybenzamine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.