What is the most important information I should know about penbutolol? Back to top

Do not stop taking penbutolol without first talking to your doctor. Stopping suddenly may make your condition worse.

If you need surgery, tell the surgeon ahead of time that you are using penbutolol. You may need to stop using the medicine for a short time.

This medication may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Drinking alcohol can increase certain side effects of penbutolol.

Penbutolol is only part of a complete program of treatment for hypertension that may also include diet, exercise, and weight control. Follow your diet, medication, and exercise routines very closely if you are being treated for hypertension.

Keep using this medicine as directed, even if you feel well. High blood pressure often has no symptoms. You may need to use blood pressure medication for the rest of your life.

What is penbutolol? Back to top

Penbutolol is a beta-blocker. Beta-blockers affect the heart and circulation (blood flow through arteries and veins).

Penbutolol is used to treat hypertension (high blood pressure).

Penbutolol may also be used for purposes not listed in this medication guide.

What should I discuss with my healthcare provider before taking penbutolol? Back to top

You should not take penbutolol if you are allergic to it, or if you have:

• asthma; or
• certain serious heart conditions such as"AV block" or slow heart rhythm.

To make sure you can safely take penbutolol, tell your doctor if you have any of these other conditions:

• kidney disease;
• liver disease;
• bronchitis, emphysema, or other breathing disorder;
• congestive heart failure;
• diabetes; or
• a thyroid disorder.

FDA pregnancy category C. It is not known whether penbutolol will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication.

It is not known whether penbutolol passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

How should I take penbutolol? Back to top

Take exactly as prescribed by your doctor. Do not take in larger or smaller amounts or for longer than recommended. Follow the directions on your prescription label.

Take penbutolol at the same time every day.

Your blood pressure will need to be checked often, and you may need other blood tests at your doctor's office. Visit your doctor regularly.

Do not stop taking this medication without first talking to your doctor. You may need to use less and less before you stop the medication completely. Stopping a beta-blocker too quickly can cause serious heart problems.

If you need surgery, tell the surgeon ahead of time that you are using penbutolol. You may need to stop using the medicine for a short time.

Penbutolol is only part of a complete program of treatment for hypertension that may also include diet, exercise, and weight control. Follow your diet, medication, and exercise routines very closely if you are being treated for hypertension.

Keep using this medicine as directed, even if you feel well. High blood pressure often has no symptoms. You may need to use blood pressure medication for the rest of your life.

Store at room temperature away from moisture, heat, and light.

What happens if I miss a dose? Back to top

Take the missed dose as soon as you remember. If your next dose is less than 8 hours away, skip the missed dose and take the medicine at the next regularly scheduled time. Do not take extra medicine to make up the missed dose.

What happens if I overdose? Back to top

Seek emergency medical attention if you think you have used too much of this medicine.

Overdose symptoms may include slow heart rate, wheezing, chest tightness, trouble breathing, weak pulse, fainting, or slow breathing.

What should I avoid while taking penbutolol? Back to top

This medication may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Drinking alcohol can increase certain side effects of penbutolol.

What are the possible side effects of penbutolol? Back to top

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

Call your doctor at once if you have a serious side effect such as:

• slow or uneven heartbeats;
• feeling short of breath, even with mild exertion;
• swelling, rapid weight gain; or
• feeling like you might pass out.

Less serious side effects may include:

• headache;
• feeling tired;
• dizziness;
• nausea, diarrhea, upset stomach;
• decreased interest in sex; or
• cold symptoms such as stuffy nose, sneezing, sore throat.

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.

What other drugs will affect penbutolol? Back to top

Tell your doctor about all other medicines you use, especially:

• digoxin (digitalis, Lanoxin);
• tizanidine (Zanaflex);
• a diuretic (water pill);
• asthma medications such as albuterol (Ventolin, Proventil), aminophylline (Phyllocontin, Truphylline), metaproterenol (Alupent), pirbuterol (Maxair), salmeterol (Advair, Serevent), terbutaline (Brethaire, Brethine, Bricanyl), or theophylline (Elixophyllin, Theo-24, Theochron, Uniphyl);
• blood pressure medications also used to treat a prostate disorder, such as doxazosin (Cardura), prazosin (Minipress), or terazosin (Hytrin);
• a calcium channel blocker such as amlodipine (Norvasc, Caduet, Exforge, Lotrel, Tekamlo, Tribenzor, Twynsta, Amturnide), diltiazem (Cartia, Cardizem), nifedipine (Nifedical, Procardia), verapamil (Calan, Covera, Isoptin, Verelan), and others; or
• heart or blood pressure medication such as clonidine (Catapres), guanabenz (Wytensin), guanfacine (Intuniv, Tenex), hydralazine (Apresoline, BiDil), methyldopa (Aldomet), or minoxidil (Loniten).

This list is not complete and other drugs may interact with penbutolol. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor.

Where can I get more information? Back to top

Your pharmacist has additional information about penbutolol written for health professionals that you may read.