Phenoxybenzamine, Oral fen-oks-ee-BEN-za-meen

What are other names for this medicine?

Type of medicine: alpha blocker

Generic and brand names: phenoxybenzamine, oral; Dibenzyline

What is this medicine used for?

This medicine is taken by mouth to treat high blood pressure and sweating caused by pheochromocytoma (a tumor of the adrenal gland). It may be used to treat other conditions as determined by your healthcare provider.

What should my healthcare provider know before I take this medicine?

Before taking this medicine, tell your healthcare provider if you have ever had:

• an allergic reaction to any medicine
• a stroke
• heart disease or a recent heart attack
• kidney disease or liver disease

Females of childbearing age: Tell your healthcare provider if you are pregnant or plan to become pregnant. It is not known whether this medicine will harm an unborn baby. Do not breast-feed while taking this medicine without with your healthcare provider's approval.

How do I take it?

Check the label on the medicine for directions about your specific dose. Take this medicine exactly as your healthcare provider prescribes. Take it regularly, even if you feel better. Do not stop taking this medicine without your healthcare provider's approval.

What if I miss a dose?

Do not miss doses. If you miss a dose, take it as soon as you remember unless it is almost time for the next scheduled dose. In that case, skip the missed dose and take the next one as directed. Do not take double doses. If you are not sure of what to do if you miss a dose, or if you miss more than one dose, contact your healthcare provider.

What if I overdose?

If you or anyone else has intentionally taken too much of this medicine, call 911 or go to the emergency room right away. If you pass out, have seizures, weakness or confusion, or have trouble breathing, call 911. If you think that you or anyone else may have taken too much of this medicine, call the poison control center. Do this even if there are no signs of discomfort or poisoning. The poison control center number is 800-222-1222.

Symptoms of an acute overdose may include: dizziness, fainting, fast heartbeat, vomiting, tiredness.

What should I watch out for?

Your healthcare provider may want you to have your blood pressure checked regularly to see how this medicine affects you. Keep all appointments.

If you need emergency care, surgery, or dental work, tell the healthcare provider or dentist you are taking this medicine.

You may feel faint when you get up quickly after sitting or lying down. Getting up slowly may lessen this reaction.

This medicine may make you drowsy or dizzy. Do not drive or operate machinery unless you are fully alert.

What are the possible side effects?

Along with its needed effects, your medicine may cause some unwanted side effects. Some side effects may be very serious. Some side effects may go away as your body adjusts to the medicine. Tell your healthcare provider if you have any side effects that continue or get worse.

Life-threatening (Report these to your healthcare provider right away). If you cannot reach your healthcare provider right away, get emergency medical care or call 911 for help): Allergic reaction (hives; itching; rash; trouble breathing; chest pain or tightness in your chest; swelling of your lips, tongue, and throat).

Serious (report these to your healthcare provider right away): Pounding or fast heartbeat, chest pain, fainting.

Other: Dizziness, drowsiness, stuffy nose, diarrhea, nausea, vomiting, trouble sleeping, headache, change in sexual desire or ability, dry mouth.

What products might interact with this medicine?

When you take this medicine with other medicines, it can change the way this or any of the other medicines work. Nonprescription medicines, vitamins, natural remedies, and certain foods may also interact. Using these products together might cause harmful side effects. Talk to your healthcare provider if you are taking:

• ACE inhibitors such as benazepril (Lotensin), captopril, enalapril (Vasotec), fosinopril, lisinopril (Prinivil, Zestril), quinapril (Accupril), and ramipril (Altace)
• angiotensin receptor II blockers such as candesartan (Atacand), eprosartan (Teveten), irbesartan (Avapro), losartan (Cozaar), olmesartan (Benicar), telmisartan (Micardis), and valsartan (Diovan)
• beta blockers such as acebutolol (Sectral), atenolol (Tenormin), carvedilol (Coreg), labetalol (Trandate), metoprolol (Lopressor, Toprol XL), nadolol (Corgard), pindolol, propranolol (Inderal LA), and sotalol (Betapace)
• calcium channel blockers such as diltiazem (Cardizem, felodipine, isradipine (DynaCirc CR), nicardipine (Cardene), nifedipine (Adalat CC, Procardia), and verapamil (Calan, Covera-HS, Isoptin SR, Verelan, Tiazac)
• decongestants taken by mouth such as phenylephrine (Sudafed PE) and pseudoephedrine (Sudafed) and nasal decongestants such as oxymetazoline (Dristan, Neo-Synephrine)
• diuretics (water pills) such as amiloride, bumetanide, chlorothiazide (Diuril), furosemide (Lasix), hydrochlorothiazide (Microzide), spironolactone (Aldactone), torsemide (Demadex), and triamterene (Dyrenium)
• medicines to treat erectile dysfunction such as sildenafil (Viagra), tadalafil (Cialis), or vardenafil (Levitra)
• natural remedies such as ephedra, garlic, ginseng, saw palmetto, and yohimbe
• other medicines to treat high blood pressure such as clonidine (Catapres), methyldopa, doxazosin (Cardura) and prazosin (Minipress)

Do not drink alcohol while you are taking this medicine.

If you are not sure if your medicines might interact, ask your pharmacist or healthcare provider. Keep a list of all your medicines with you. List all the prescription medicines, nonprescription medicines, supplements, natural remedies, and vitamins that you take. Be sure that you tell all healthcare providers who treat you about all the products you are taking.

How should I store this medicine?

Store this medicine at room temperature. Keep the container tightly closed. Protect it from heat, high humidity, and bright light.

This advisory includes selected information only and may not include all side effects of this medicine or interactions with other medicines. Ask your healthcare provider or pharmacist for more information or if you have any questions.

Ask your pharmacist for the best way to dispose of outdated medicine or medicine you have not used. Do not throw medicine in the trash.

Keep all medicines out of the reach of children.

Do not share medicines with other people.