Phentolamine, Injection fen-TOHL-a-meen

What are other names for this medicine?

Type of medicine: alpha-adrenergic blocker

Generic and brand names: phentolamine, injection

What is this medicine used for?

This medicine is given by injection (shots) to test for pheochromocytoma (a tumor of the adrenal gland). This medicine is also used to prevent or control high blood pressure caused by this kind of tumor when you have surgery.

This medicine is also used to prevent or control tissue damage from certain medicines given by injection leak into nearby tissue.

It may be used for 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
• heart disease, a heart attack, angina, or an irregular heartbeat
• kidney disease

Tell your healthcare provider about all the medicines you are taking, including medicines for high blood pressure. If you are receiving this medicine as a diagnostic test, do not take any sleeping pills or narcotic pain relievers (such as codeine or morphine) within 24 hours of your test. Talk with your healthcare provider about this.

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 your healthcare provider's approval.

How do I use it?

Your healthcare provider will give you this medicine by IV infusion (slow drip through a needle into your vein) or by injection (a shot).

What should I watch out for?

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

You may feel dizzy or faint when you get up quickly after sitting or lying down. Getting up slowly may help.

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

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): Fast or irregular heartbeat, chest pain, dizziness, fainting, severe headache, trouble talking, vision changes.

Other: Weakness, flushing, nausea, vomiting, diarrhea, stuffy nose.

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)
• alpha blockers such as doxazosin (Cardura) and prazosin (Minipress)
• 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, Tiazac), felodipine, isradipine (DynaCirc CR), nicardipine (Cardene), nifedipine (Adalat CC, Procardia), and verapamil (Calan, Covera-HS, Isoptin SR, Verelan)
• diuretics (water pills) such as amiloride, bumetanide, chlorothiazide (Diuril), furosemide (Lasix), hydrochlorothiazide (Microzide), spironolactone (Aldactone), torsemide (Demadex), and triamterene (Dyrenium)
• epinephrine (Adrenalin)
• cold or allergy medicines or weight loss medicines that contain ephedrine, phenylephrine (Neo-Synephrine), or pseudoephedrine (Sudafed)
• erectile dysfunction medicine such as sildenafil (Viagra), tadalafil (Cialis), and vardenafil (Levitra)
• medicines to treat pulmonary hypertension such as sildenafil (Revatio) and treprostinil (Remodulin)

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.

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.

Keep all medicines out of the reach of children.

Do not share medicines with other people.