Lopressor, a type of medication known as a beta blocker, is used in the treatment of high blood pressure, angina pectoris (chest pain, usually caused by lack of oxygen to the heart due to clogged arteries), and heart attack. When prescribed for high blood pressure, it is effective when used alone or in combination with other high blood pressure medications. Beta blockers decrease the force and rate of heart contractions, thereby reducing the demand for oxygen and lowering blood pressure.

Occasionally doctors prescribe Lopressor for the treatment of aggressive behavior, prevention of migraine headache, and relief of temporary anxiety.

An extended-release form of metoprolol, called Toprol-XL, is prescribed for high blood pressure, angina, and heart failure.

Most important fact about Lopressor

If you have high blood pressure, you must take Lopressor regularly for it to be effective. Since blood pressure declines gradually, it may be several weeks before you get the full benefit of Lopressor; and you must continue taking it even if you are feeling well. Lopressor does not cure high blood pressure; it merely keeps it under control.

How should you take Lopressor?

Lopressor should be taken with food or immediately after you have eaten.

Take Lopressor exactly as prescribed, even if your symptoms have disappeared.

Try not to miss any doses. If Lopressor is not taken regularly, your condition may worsen.

--If you miss a dose...

If it is within 4 hours of your next dose, skip the one you missed and go back to your regular schedule. Never take 2 doses at the same time.

--Storage instructions...

Store Lopressor at room temperature in a tightly closed container, away from light. Protect from moisture. Store Toprol-XL at room temperature.

What side effects may occur?

Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking Lopressor.

• More common side effects may include:
  Depression, diarrhea, dizziness, itching, rash, shortness of breath, slow heartbeat, tiredness

Why should Lopressor not be prescribed?

If you have a slow heartbeat, certain heart irregularities, low blood pressure, inadequate output from the heart, or heart failure, you should not take Lopressor.

Special warnings about Lopressor

If you have a history of congestive heart failure, Lopressor should be used with caution. If you are taking the extended release form of Lopressor, Toprol-XL, to relieve heart failure, the condition may temporarily be worsened as your dosage is increased. Be sure to alert your doctor to any signs of worsening heart failure such as weight gain or increasing shortness of breath. If you have peripheral vascular disease, use Toprol-XL with caution.

Do not stop Lopressor abruptly. This can cause increased chest pain and heart attack. Dosage should be gradually reduced.

If you suffer from asthma, seasonal allergies or other bronchial conditions, or liver disease, Lopressor should be used with caution.

Ask your doctor if you should check your pulse while taking Lopressor. This medication can cause your heartbeat to become too slow.

This medication may mask some symptoms of low blood sugar in diabetics or alter blood sugar levels. If you are diabetic, discuss this with your doctor.

If you have pheochromocytoma and your doctor prescribes Toprol-XL, you will first need to take an alpha-blocking drug (a different type of blood pressure medication).

Lopressor may cause you to become drowsy or less alert; therefore, driving or operating dangerous machinery or participating in any hazardous activity that requires full mental alertness is not recommended until you know how you respond to Lopressor.

Notify your doctor or dentist that you are taking Lopressor if you have a medical emergency, or before you have surgery or dental treatment.

Notify your doctor if you have any difficulty in breathing.

Possible food and drug interactions when taking Lopressor

If Lopressor is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining Lopressor with certain high blood pressure drugs such as reserpine (Ser-Ap-Es).

Other medications that might interact with Lopressor include:

Albuterol (Proventil, Ventolin)
Amiodarone (Cordarone)
Barbiturates such as phenobarbital
Calcium channel blockers such as Calan and Cardizem
Cimetidine (Tagamet)
Ciprofloxacin (Cipro)
Clonidine (Catapres)
Epinephrine (EpiPen)
Fluoxetine (Prozac)
Hydralazine (Apresoline)
Insulin
Nonsteroidal anti-inflammatory drugs such as Motrin and Indocin
Oral diabetes drugs such as Glucotrol and Micronase
Paroxetine (Paxil)
Prazosin (Minipress)
Propafenone (Rythmol)
Quinidine (Quinaglute)
Ranitidine (Zantac)
Rifampin (Rifadin)

Special information if you are pregnant or breastfeeding

The effects of Lopressor during pregnancy have not been adequately studied. If you are pregnant or plan to become pregnant, inform your doctor immediately. Lopressor appears in breast milk and could affect a nursing infant. If Lopressor is essential to your health, your doctor may advise you to discontinue breastfeeding until your treatment with Lopressor is finished.

Recommended dosage

ADULTS

Dosages of Lopressor should be individualized by your doctor. It should be taken with or immediately following meals.

High Blood Pressure

The usual starting dosage of Lopressor is a total of 100 milligrams a day taken in 1 or 2 doses, whether taken alone or with a diuretic. The initial dosage of Toprol-XL ranges from 50 to 100 milligrams once a day. Your doctor may gradually increase the dosage up to 400 milligrams a day. Generally, the effectiveness of each dosage increase will be seen within a week.

Angina Pectoris

The usual starting dosage is a total of 100 milligrams a day taken in 2 doses of Lopressor or a single dose of Toprol-XL. Your doctor may gradually increase the dosage up to 400 milligrams a day.

Generally, the effectiveness of each dosage increase will be seen within a week. If treatment is to be discontinued, your doctor will withdraw the drug gradually over a period of 1 to 2 weeks.

Heart Attack

Lopressor can be used for treatment of heart attack both in the hospital during the early phases and after the individual's condition has stabilized. Your doctor will determine the dosage according to your needs.

Heart Failure

The recommended starting dose of Toprol-XL is 25 milligrams once daily for 2 weeks (12.5 milligrams in severe cases). Your doctor will double the dose every 2 weeks up to the highest level that works without side effects. The maximum recommended dose is 200 milligrams daily.

CHILDREN

The safety and effectiveness of Lopressor have not been established in children.