Phenoxybenzamine is used to treat episodes of high blood pressure and sweating related to pheochromocytoma.
This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.
Phenoxybenzamine comes as a capsule to take by mouth. It usually is taken two or three times a day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take phenoxybenzamine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Phenoxybenzamine controls symptoms related to pheochromocytoma and controls bladder symptoms but does not cure them. Continue to take phenoxybenzamine even if you feel well. Do not stop taking phenoxybenzamine without talking to your doctor.
Phenoxybenzamine is also used to control bladder problems such as urgency, frequency, and inability to control urination in patients with neurogenic bladder, functional outlet obstruction, and partial prostatic obstruction. Talk to your doctor about the possible risks of using this drug for your condition.
Before taking phenoxybenzamine,
- tell your doctor and pharmacist if you are allergic to phenoxybenzamine or any other drugs.
- tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially medications for diet control, high blood pressure, asthma, cough, colds, allergies, and glaucoma; and vitamins.
- tell your doctor if you have or have ever had heart or kidney disease, a stroke, or transient ischemic attacks (TIA).
- tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking phenoxybenzamine, call your doctor immediately.
- if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking phenoxybenzamine.
- you should know that this drug may make you drowsy. Do not drive a car or operate machinery until you know how this drug affects you.
- remember that alcohol can add to the drowsiness caused by this drug.
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
Phenoxybenzamine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- nasal congestion
- upset stomach
- sexual dysfunction (difficulty ejaculating)
If you experience any of the following symptoms, call your doctor immediately:
- fast heartbeat
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at Web Site] or by phone [1-800-332-1088].
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.
Keep all appointments with your doctor and the laboratory. Your blood pressure should be checked regularly to determine your response to phenoxybenzamine.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
AHFS® Consumer Medication Information. © Copyright, The American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.
Last Reviewed: September 1, 2010.