Beta-adrenergic Blocking Agents (Systemic)

Before Using This Medicine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For the beta-blockers, the following should be considered:

Allergies - Tell your doctor if you have ever had any unusual or allergic reaction to the beta-blocker medicine prescribed. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy - Use of some beta-blockers during pregnancy has been associated with low blood sugar, breathing problems, a lower heart rate, and low blood pressure in the newborn infant. Other reports have not shown unwanted effects on the newborn infant. Animal studies have shown some beta-blockers to cause problems in pregnancy when used in doses many times the usual human dose. Before taking any of these medicines, make sure your doctor knows if you are pregnant or if you may become pregnant.

Breast-feeding - It is not known whether bisoprolol, carteolol, or penbutolol passes into breast milk. All other beta-blockers pass into breast milk. Problems such as slow heartbeat, low blood pressure, and trouble in breathing have been reported in nursing babies. Mothers who are taking beta-blockers and who wish to breast-feed should discuss this with their doctor.

Children - Some of these medicines have been used in children and, in effective doses, have not been shown to cause different side effects or problems in children than they do in adults.

Older adults - Some side effects are more likely to occur in the elderly, who are usually more sensitive to the effects of beta-blockers. Also, beta-blockers may reduce tolerance to cold temperatures in elderly patients.

Other medicines - Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking or receiving a beta-blocker it is especially important that your health care professional know if you are taking any of the following:

• Allergen immunotherapy (allergy shots) or
• Allergen extracts for skin testing - Beta-blockers may increase the risk of serious allergic reaction to these medicines

• Aminophylline (e.g., Somophyllin) or
• Caffeine (e.g., NoDoz) or
• Dyphylline (e.g., Lufyllin) or
• Oxtriphylline (e.g., Choledyl) or
• Theophylline (e.g., Somophyllin-T) - The effects of both these medicines and beta-blockers may be blocked; in addition, theophylline levels in the body may be increased, especially in patients who smoke

• Antidiabetics, oral (diabetes medicine you take by mouth) or
• Insulin - There is an increased risk of hyperglycemia (high blood sugar); beta-blockers may cover up certain symptoms of hypoglycemia (low blood sugar) such as increases in pulse rate and blood pressure, and may make the hypoglycemia last longer

• Calcium channel blockers (bepridil [e.g., Bepadin], diltiazem [e.g., Cardizem], felodipine [e.g., Plendil], flunarizine [e.g., Sibelium], isradipine [e.g., DynaCirc], nicardipine [e.g., Cardene], nifedipine [e.g., Procardia], nimodipine [e.g., Nimotop], verapamil [e.g., Calan]) or
• Clonidine (e.g., Catapres) or
• Guanabenz (e.g., Wytensin) - Effects on blood pressure may be increased. In addition, unwanted effects may occur if clonidine, guanabenz, or a beta-blocker is stopped suddenly after use together. Unwanted effects on the heart may occur when beta-blockers are used with calcium channel blockers

• Cocaine - Cocaine may block the effects of beta-blockers; in addition, there is an increased risk of high blood pressure, fast heartbeat, and possibly heart problems if you use cocaine while taking a beta-blocker

• Monoamine oxidase (MAO) inhibitor activity (isocarboxazid [e.g., Marplan], isocarboxazid [e.g., Marplan], phenelzine [e.g., Nardil], procarbazine [e.g., Matulane], selegiline [e.g., Eldepryl], tranylcypromine [e.g., Parnate]) - Taking beta-blockers while you are taking or within 2 weeks of taking monoamine oxidase (MAO) inhibitors may cause severe high blood pressure

Other medical problems - The presence of other medical problems may affect the use of the beta blockers. Make sure you tell your doctor if you have any other medical problems, especially:

• Allergy, history of (asthma, eczema, hay fever, hives), or
• Bronchitis or
• Emphysema - Severity and duration of allergic reactions to other substances may be increased; in addition, beta-blockers can increase trouble in breathing

• Bradycardia (unusually slow heartbeat) or
• Heart or blood vessel disease - There is a risk of further decreased heart function; also, if treatment is stopped suddenly, unwanted effects may occur

• Diabetes mellitus (sugar diabetes) - Beta-blockers may cause hyperglycemia (high blood sugar) and circulation problems; in addition, if your diabetes medicine causes your blood sugar to be too low, beta-blockers may cover up some of the symptoms (fast heartbeat), although they will not cover up other symptoms such as dizziness or sweating

• Kidney disease or
• Liver disease - Effects of beta-blockers may be increased because of slower removal from the body

• Mental depression (or history of) - May be increased by beta-blockers

• Myasthenia gravis or
• Psoriasis - Beta-blockers may make these conditions worse

• Overactive thyroid - Stopping beta-blockers suddenly may increase symptoms; beta-blockers may cover up fast heartbeat, which is a sign of overactive thyroid