Medically reviewed by Drugs.com. Last updated on Feb 25, 2021.
Following abrupt cessation of therapy with certain beta-blocking agents, exacerbations of angina pectoris and, in some cases, myocardial infarction have occurred. The dosage should be gradually reduced over a period of 1 to 2 weeks and the patient should be carefully monitored when discontinuing chronic therapy. If angina markedly worsens or acute coronary insufficiency develops, metoprolol tartrate administration should be reinstated promptly, at least temporarily, and other measures appropriate for the management of unstable angina should be taken. Patients should be warned against interruption or discontinuation of therapy without the physician's advice. Because coronary artery disease is common and may be unrecognized, it may be prudent not to discontinue metoprolol tartrate therapy abruptly even in patients treated only for hypertension .
Commonly used brand name(s)
In the U.S.
Available Dosage Forms:
Therapeutic Class: Cardiovascular Agent
Pharmacologic Class: Beta-Adrenergic Blocker, Cardioselective
Uses for Lopressor
Metoprolol injection is used to reduce the risk of death from an acute heart attack. It is given to people who have already had a heart attack.
This medicine is a beta-blocker. It works by affecting the response to nerve impulses in certain parts of the body, like the heart. As a result, the heart beats slower and decreases the blood pressure. When the blood pressure is lowered, the amount of blood and oxygen is increased to the heart.
This medicine is available only with your doctor's prescription.
Before using Lopressor
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 this medicine, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies have not been performed on the relationship of age to the effects of metoprolol injection in the pediatric population. Safety and efficacy have not been established.
Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of metoprolol injection in the elderly. However, elderly patients may be more sensitive to the effects of metoprolol injection than younger adults and are more likely to have age-related liver or heart problems, which may require caution and an adjustment in the dose for patients receiving metoprolol injection.
Studies in women suggest that this medication poses minimal risk to the infant when used during breastfeeding.
Interactions with 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 receiving this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Amtolmetin Guacil
- Choline Salicylate
- Flufenamic Acid
- Insulin Aspart, Recombinant
- Insulin Degludec
- Insulin Detemir
- Insulin Glargine, Recombinant
- Insulin Glulisine
- Insulin Human Inhaled
- Insulin Human Isophane (NPH)
- Insulin Human Regular
- Insulin Lispro, Recombinant
- Mefenamic Acid
- Niflumic Acid
- Nimesulide Beta Cyclodextrin
- Salicylic Acid
- Sodium Salicylate
- St John's Wort
- Tiaprofenic Acid
- Tolfenamic Acid
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other medical problems
The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:
- Blood circulation problems or
- Bradycardia (slow heartbeat) or
- Heart block or
- Heart failure, moderate to severe or
- Sick-sinus syndrome (heart rhythm problem)—Should not be used in patients with these conditions.
- Diabetes or
- Hyperthyroidism (overactive thyroid) or
- Hypoglycemia (low blood sugar)—May cover up some of the signs and symptoms of these diseases, such as a fast heartbeat.
- Hypotension (low blood pressure) or
- Ischemic heart disease or
- Lung disease (eg, asthma, bronchitis, emphysema) or
- Pheochromocytoma (adrenal gland tumor)—Use with caution. May make these conditions worse.
- Liver disease—Use with caution. The effects may be increased because of slower removal of the medicine from the body.
Proper use of Lopressor
A nurse or other trained health professional will give you this medicine. This medicine is given through a needle placed in one of your veins.
Your doctor will only give you a few doses of this medicine until your condition improves, and then you will be switched to an oral medicine that works the same way. If you have any concerns about this, talk to your doctor.
Precautions while using Lopressor
It is very important that your doctor check you closely to make sure this medicine is working properly and to check for unwanted effects.
Metoprolol injection may worsen the symptoms of heart failure in some patients. Tell your doctor right away if you are having chest pain or discomfort, dilated neck veins, extreme fatigue, irregular breathing, an irregular heartbeat, shortness of breath, swelling of the face, fingers, feet, or lower legs, weight gain, or wheezing.
This medicine may cause changes in your blood sugar levels. Also, this medicine may cover up signs of low blood sugar, such as a rapid pulse rate. Check with your doctor if you have these problems or if you notice a change in the results of your blood or urine sugar tests.
Make sure any doctor or dentist who treats you knows that you are using this medicine. You may need to stop receiving this medicine several days before having surgery.
This medicine may cause some people to become less alert than they are normally. if this side effect occurs, do not drive, use machines, or do anything else that could be dangerous if you are not alert while using metoprolol injection.
Dizziness, lightheadedness, or even fainting may occur when you get up suddenly from a lying or sitting position. Getting up slowly may help lessen this problem. Also, lying down for a while may relieve dizziness or lightheadedness.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.
Lopressor side effects
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor or nurse immediately if any of the following side effects occur:
- Blurred vision
- chest pain or discomfort
- dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
- shortness of breath
- slow or irregular heartbeat
- unusual tiredness or weakness
- Bloating or swelling of the face, arms, hands, lower legs, or feet
- decreased urine output
- difficult or labored breathing
- dilated neck veins
- disturbed color perception
- double vision
- extreme fatigue
- fast, pounding, or racing heartbeat or pulse
- halos around lights
- irregular breathing
- loss of vision
- mental confusion
- night blindness
- noisy breathing
- overbright appearance of lights
- pain, tension, and weakness upon walking that subsides during periods of rest
- paleness or cold feeling in the fingertips and toes
- rapid weight gain
- seeing, hearing, or feeling things that are not there
- short-term memory loss
- swelling of the face, fingers, feet, or lower legs
- tightness in the chest
- tingling of the hands or feet
- tingling or pain in the fingers or toes when exposed to cold
- troubled breathing
- tunnel vision
- unusual weight gain or loss
- Bluish color skin of the fingers or toes
- clay-colored stools
- continuing loss of appetite
- continuing or severe abdominal or stomach pain
- continuing or severe nausea and vomiting
- dark urine
- difficulty with moving
- general tiredness and weakness
- increased frequency of urination
- itching skin
- light-colored stools
- lower back or side pain
- muscle pain or stiffness
- numbness of the fingers or toes
- pain, swelling, or redness in the joints
- painful or difficult urination
- sore throat
- sores, ulcers, or white spots on the lips or in the mouth
- unpleasant breath odor
- unusual bleeding or bruising
- upper right abdominal or stomach pain
- vomiting of blood
- yellow eyes and skin
Get emergency help immediately if any of the following symptoms of overdose occur:
Symptoms of overdose
- Bluish color of the fingernails, lips, skin, palms, or nail beds
- change in consciousness
- loss of consciousness
- no blood pressure or pulse
- stopping of heart
- very drowsy or sleepy
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
- decreased interest in sexual intercourse
- difficulty having a bowel movement (stool)
- dry mouth
- excess air or gas in the stomach or intestines
- feeling of constant movement of self or surroundings
- feeling of indigestion
- feeling sad or empty
- full feeling
- inability to have or keep an erection
- loss in sexual ability, desire, drive, or performance
- loss of interest or pleasure
- pain in the chest below the breastbone
- passing gas
- redness or other discoloration of the skin
- sensation of spinning
- trouble concentrating
- trouble sleeping
- Bone pain
- continuing ringing or buzzing or other unexplained noise in the ears
- hearing loss
- increased sensitivity of the skin to sunlight
- pain of penis on erection
- severe sunburn
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Frequently asked questions
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More about Lopressor (metoprolol)
- Side Effects
- During Pregnancy or Breastfeeding
- Dosage Information
- Drug Images
- Drug Interactions
- Pricing & Coupons
- En Español
- 14 Reviews
- Generic Availability
- Drug class: cardioselective beta blockers
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