Lopressor 100mg Tablets
It is used to treat high blood pressure.It is used to treat some types of chest pain (angina).It is used after a heart attack to help prevent future heart attacks and lengthen life. It may be given to you for other reasons. Talk with the doctor.
Drug Class
Antihypertensive, Antianginal, Antiarrhythmic
Pharmacologic Class
Beta-1 Selective Adrenergic Blocker
Pregnancy Category
Category C
FDA Approved
Jun 1978
DEA Schedule
Not Controlled
Overview
What is this medicine?
Metoprolol is a type of medicine called a beta-blocker. It works by slowing down your heart rate and relaxing blood vessels, which helps to lower your blood pressure and reduce the strain on your heart. It's used to treat high blood pressure, chest pain (angina), and to help people recover after a heart attack.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided. Take your medication with or immediately after a meal. Continue taking your medication as directed by your doctor or healthcare provider, even if you start feeling well.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry location, avoiding the bathroom. Protect it from heat to maintain its effectiveness.
Missing a Dose
If you miss a dose, skip it and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for the missed one.
To use this medication correctly, follow your doctor's instructions and read all the information provided. Take your medication with or immediately after a meal. Continue taking your medication as directed by your doctor or healthcare provider, even if you start feeling well.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry location, avoiding the bathroom. Protect it from heat to maintain its effectiveness.
Missing a Dose
If you miss a dose, skip it and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses to make up for the missed one.
Lifestyle & Tips
- Take exactly as prescribed, do not stop abruptly without consulting your doctor.
- Monitor your blood pressure and heart rate regularly at home if advised.
- Maintain a healthy diet (low sodium, low fat) and engage in regular physical activity as recommended by your doctor.
- Limit alcohol intake.
- Avoid activities requiring mental alertness until you know how the medication affects you (may cause dizziness or drowsiness).
- Inform all healthcare providers that you are taking metoprolol.
Available Forms & Alternatives
Available Strengths:
Generic Alternatives:
Dosing & Administration
Adult Dosing
Standard Dose:
Hypertension: 100 mg daily in single or divided doses. Angina Pectoris: 100 mg daily in single or divided doses. Myocardial Infarction: Acute phase: 5 mg IV every 2 minutes for 3 doses, then 50 mg orally every 6 hours for 48 hours. Long-term: 100 mg orally twice daily.
Dose Range:
50 - 450 mg
Condition-Specific Dosing:
hypertension:
Initial: 50-100 mg/day, max 450 mg/day
anginaPectoris:
Initial: 100 mg/day, max 400 mg/day
myocardialInfarction:
Acute: IV then oral; Long-term: 100 mg twice daily
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established
Child:
Hypertension: 1-5 mg/kg/day divided twice daily (off-label, limited data)
Adolescent:
Hypertension: 1-5 mg/kg/day divided twice daily (off-label, limited data)
Dose Adjustments
Renal Impairment:
Mild:
No adjustment typically needed
Moderate:
No adjustment typically needed
Severe:
No adjustment typically needed
Dialysis:
Not significantly removed by hemodialysis; no supplemental dose needed.
Hepatic Impairment:
Mild:
Consider lower initial dose
Moderate:
Reduce dose significantly (e.g., by 50%)
Severe:
Reduce dose significantly (e.g., by 75%) and monitor closely
Pharmacology
Mechanism of Action
Metoprolol is a cardioselective beta-1 adrenergic receptor blocker. It selectively blocks beta-1 receptors, primarily located in the heart, reducing heart rate, myocardial contractility, and cardiac output. At higher doses, it can also block beta-2 receptors. It reduces renin release from the kidneys.
Pharmacokinetics
Absorption:
Bioavailability:
Approximately 50% (due to significant first-pass metabolism)
Tmax:
1.5-2 hours
FoodEffect:
Food increases bioavailability by 20-40%
Distribution:
Vd:
3.2-5.6 L/kg
ProteinBinding:
Approximately 10-12%
CnssPenetration:
Limited
Elimination:
HalfLife:
3-7 hours
Clearance:
Approximately 1 L/min
ExcretionRoute:
Renal (primarily metabolites)
Unchanged:
Approximately 3-10%
Pharmacodynamics
OnsetOfAction:
Within 1 hour (oral)
PeakEffect:
1.5-2 hours (oral)
DurationOfAction:
6-12 hours (dose-dependent)
Safety & Warnings
BLACK BOX WARNING
Following abrupt cessation of therapy with certain beta-blocking agents, exacerbations of angina pectoris and, in some cases, myocardial infarction have occurred. When discontinuing chronically administered metoprolol, particularly in patients with ischemic heart disease, the dosage should be gradually reduced over a period of 1 to 2 weeks and the patient should be carefully monitored. If angina markedly worsens or acute coronary insufficiency develops, metoprolol administration should be reinstituted promptly, at least temporarily, and other measures appropriate for the management of unstable angina pectoris should be taken. Because coronary artery disease is common and may be unrecognized, it may be prudent not to discontinue metoprolol therapy abruptly even in patients treated only for hypertension.
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
Although rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor or seek immediate medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of low blood sugar, including:
+ Dizziness
+ Headache
+ Feeling sleepy
+ Feeling weak
+ Shaking
+ Fast heartbeat
+ Confusion
+ Hunger
+ Sweating
Depression
Severe dizziness or fainting
New or worsening chest pain
New or worsening abnormal heartbeat
Slow heartbeat
Shortness of breath, significant weight gain, or swelling in the arms or legs
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms that bother you or do not go away, contact your doctor:
Feeling dizzy, tired, or weak
Diarrhea
Upset stomach
Vomiting
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor or seek immediate medical attention:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of low blood sugar, including:
+ Dizziness
+ Headache
+ Feeling sleepy
+ Feeling weak
+ Shaking
+ Fast heartbeat
+ Confusion
+ Hunger
+ Sweating
Depression
Severe dizziness or fainting
New or worsening chest pain
New or worsening abnormal heartbeat
Slow heartbeat
Shortness of breath, significant weight gain, or swelling in the arms or legs
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms that bother you or do not go away, contact your doctor:
Feeling dizzy, tired, or weak
Diarrhea
Upset stomach
Vomiting
Reporting Side Effects
This list is not exhaustive, and you may experience other side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Severe dizziness or fainting
- Very slow heart rate (less than 50 beats per minute)
- Difficulty breathing or wheezing
- Swelling in your ankles or feet
- Unusual weight gain
- New or worsening chest pain
- Symptoms of depression (e.g., persistent sadness, loss of interest)
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
Certain heart conditions, including:
+ Abnormal heart rhythms (heart block or sick-sinus syndrome)
+ Heart failure (a weakened heart)
+ Low blood pressure
+ Poor circulation to your arms or legs
+ Shock caused by heart problems
+ A slow heartbeat
Respiratory issues, such as:
+ Asthma
+ Chronic obstructive pulmonary disease (COPD) or other breathing problems
This list is not exhaustive, and it is crucial to discuss all your health problems and medications with your doctor. Please inform your doctor and pharmacist about:
All prescription and over-the-counter (OTC) medications you are taking
Any natural products or vitamins you are using
All your health problems, including those not listed above
To ensure your safety, always check with your doctor before:
Starting a new medication
Stopping a medication
* Changing the dosage of any medication
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
Certain heart conditions, including:
+ Abnormal heart rhythms (heart block or sick-sinus syndrome)
+ Heart failure (a weakened heart)
+ Low blood pressure
+ Poor circulation to your arms or legs
+ Shock caused by heart problems
+ A slow heartbeat
Respiratory issues, such as:
+ Asthma
+ Chronic obstructive pulmonary disease (COPD) or other breathing problems
This list is not exhaustive, and it is crucial to discuss all your health problems and medications with your doctor. Please inform your doctor and pharmacist about:
All prescription and over-the-counter (OTC) medications you are taking
Any natural products or vitamins you are using
All your health problems, including those not listed above
To ensure your safety, always check with your doctor before:
Starting a new medication
Stopping a medication
* Changing the dosage of any medication
Precautions & Cautions
Important Warnings and Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.
Caution with Daily Activities
Until you know how this medication affects you, avoid driving and other activities that require you to be alert. To minimize the risk of dizziness or fainting, get up slowly from a sitting or lying down position, and be cautious when climbing stairs.
Monitoring Your Condition
Follow your doctor's instructions for checking your blood pressure and heart rate. Additionally, have your blood work and other laboratory tests done as directed by your doctor.
Interference with Lab Tests
This medication may affect certain laboratory tests. Be sure to inform all your healthcare providers and laboratory personnel that you are taking this medication.
Risk of Low Blood Sugar
This medication may mask symptoms of low blood sugar, such as a rapid heartbeat, which can increase the risk of severe or prolonged low blood sugar. This is particularly concerning for individuals with diabetes, children, and those who are fasting, undergoing surgery, or experiencing nausea and vomiting. If you have questions or concerns, discuss them with your doctor.
Managing High Blood Sugar
If you have diabetes, it is crucial to closely monitor your blood sugar levels while taking this medication.
Interactions with Other Medications
If you have high blood pressure and are taking this medication, consult your doctor before using over-the-counter products that may increase blood pressure, such as cough and cold medications, diet pills, stimulants, non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen, and certain natural products or aids.
Stopping the Medication
Do not stop taking this medication abruptly, as this may lead to worsening chest pain or even a heart attack, especially if you have certain types of heart disease. To avoid side effects, your doctor will instruct you on how to gradually stop taking this medication. If you experience new or worsening chest pain or other heart problems, contact your doctor immediately.
Thyroid Conditions
This medication may make it more challenging to recognize symptoms of an overactive thyroid, such as a rapid heartbeat. If you have an overactive thyroid and stop taking this medication suddenly, your condition may worsen and become life-threatening. Discuss this with your doctor.
Allergic Reactions
If you have a history of severe allergic reactions, inform your doctor. You may be at risk of a more severe reaction if you are exposed to the allergen again. If you use epinephrine to treat severe allergic reactions, consult your doctor, as this medication may reduce the effectiveness of epinephrine.
Alcohol Consumption
Discuss your alcohol consumption with your doctor before taking this medication.
Pregnancy and Breastfeeding
If you are pregnant, plan to become pregnant, or are breastfeeding, inform your doctor. You will need to discuss the benefits and risks of this medication to you and your baby.
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.
Caution with Daily Activities
Until you know how this medication affects you, avoid driving and other activities that require you to be alert. To minimize the risk of dizziness or fainting, get up slowly from a sitting or lying down position, and be cautious when climbing stairs.
Monitoring Your Condition
Follow your doctor's instructions for checking your blood pressure and heart rate. Additionally, have your blood work and other laboratory tests done as directed by your doctor.
Interference with Lab Tests
This medication may affect certain laboratory tests. Be sure to inform all your healthcare providers and laboratory personnel that you are taking this medication.
Risk of Low Blood Sugar
This medication may mask symptoms of low blood sugar, such as a rapid heartbeat, which can increase the risk of severe or prolonged low blood sugar. This is particularly concerning for individuals with diabetes, children, and those who are fasting, undergoing surgery, or experiencing nausea and vomiting. If you have questions or concerns, discuss them with your doctor.
Managing High Blood Sugar
If you have diabetes, it is crucial to closely monitor your blood sugar levels while taking this medication.
Interactions with Other Medications
If you have high blood pressure and are taking this medication, consult your doctor before using over-the-counter products that may increase blood pressure, such as cough and cold medications, diet pills, stimulants, non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen, and certain natural products or aids.
Stopping the Medication
Do not stop taking this medication abruptly, as this may lead to worsening chest pain or even a heart attack, especially if you have certain types of heart disease. To avoid side effects, your doctor will instruct you on how to gradually stop taking this medication. If you experience new or worsening chest pain or other heart problems, contact your doctor immediately.
Thyroid Conditions
This medication may make it more challenging to recognize symptoms of an overactive thyroid, such as a rapid heartbeat. If you have an overactive thyroid and stop taking this medication suddenly, your condition may worsen and become life-threatening. Discuss this with your doctor.
Allergic Reactions
If you have a history of severe allergic reactions, inform your doctor. You may be at risk of a more severe reaction if you are exposed to the allergen again. If you use epinephrine to treat severe allergic reactions, consult your doctor, as this medication may reduce the effectiveness of epinephrine.
Alcohol Consumption
Discuss your alcohol consumption with your doctor before taking this medication.
Pregnancy and Breastfeeding
If you are pregnant, plan to become pregnant, or are breastfeeding, inform your doctor. You will need to discuss the benefits and risks of this medication to you and your baby.
Overdose Information
Overdose Symptoms:
- Severe bradycardia (very slow heart rate)
- Hypotension (very low blood pressure)
- Cardiogenic shock
- Bronchospasm
- Heart failure
- Hypoglycemia
- Cardiac arrest
What to Do:
Seek immediate medical attention. Call 911 or your local emergency number. For poison control, call 1-800-222-1222.
Drug Interactions
Major Interactions
- Fingolimod (severe bradycardia)
- Verapamil (additive negative inotropic and chronotropic effects, severe bradycardia/heart block)
- Diltiazem (additive negative inotropic and chronotropic effects, severe bradycardia/heart block)
- Clonidine (rebound hypertension upon clonidine withdrawal if beta-blocker not stopped first)
Moderate Interactions
- CYP2D6 inhibitors (e.g., fluoxetine, paroxetine, quinidine, propafenone, ritonavir, bupropion, terbinafine) - increased metoprolol levels
- Other antihypertensives (additive hypotensive effects)
- NSAIDs (may reduce antihypertensive effect)
- Digitalis glycosides (additive bradycardia)
- Insulin/oral hypoglycemics (may mask symptoms of hypoglycemia)
- Sympathomimetics (e.g., epinephrine, norepinephrine - may cause hypertension followed by bradycardia)
Minor Interactions
- Alcohol (may increase metoprolol levels slightly)
- Cimetidine (may increase metoprolol levels)
Monitoring
Baseline Monitoring
Blood Pressure (BP)
Rationale: To establish baseline and guide initial dosing.
Timing: Prior to initiation
Heart Rate (HR)
Rationale: To establish baseline and assess risk of bradycardia.
Timing: Prior to initiation
Electrocardiogram (ECG)
Rationale: To assess for pre-existing conduction abnormalities.
Timing: Prior to initiation (especially in patients with cardiac history)
Renal Function (SCr, BUN)
Rationale: To assess overall health and potential for drug accumulation in severe renal impairment (though not primary elimination route).
Timing: Prior to initiation
Liver Function Tests (ALT, AST, bilirubin)
Rationale: To assess hepatic impairment, as metoprolol is extensively metabolized by the liver.
Timing: Prior to initiation
Routine Monitoring
Blood Pressure (BP)
Frequency: Regularly (e.g., weekly during titration, then monthly/quarterly)
Target: <130/80 mmHg (individualized)
Action Threshold: Systolic >140 mmHg or Diastolic >90 mmHg (consider dose increase); Systolic <90 mmHg or symptomatic hypotension (consider dose decrease)
Heart Rate (HR)
Frequency: Regularly (e.g., weekly during titration, then monthly/quarterly)
Target: 50-70 bpm (resting)
Action Threshold: <50 bpm or symptomatic bradycardia (consider dose decrease or discontinuation)
Symptoms of Heart Failure
Frequency: At each visit
Target: Not applicable
Action Threshold: Worsening dyspnea, edema, weight gain (evaluate for heart failure exacerbation)
Glucose Levels (in diabetics)
Frequency: Regularly (as per diabetes management guidelines)
Target: Individualized
Action Threshold: Unexplained hypoglycemia or hyperglycemia (beta-blockers can mask hypoglycemia symptoms)
Symptom Monitoring
- Dizziness
- Lightheadedness
- Fatigue
- Bradycardia (slow pulse)
- Shortness of breath
- Wheezing
- Cold hands/feet
- Depression
- Insomnia
- Sexual dysfunction
Special Patient Groups
Pregnancy
Metoprolol is Pregnancy Category C. Use during pregnancy only if the potential benefit justifies the potential risk to the fetus. Beta-blockers can cause bradycardia, hypoglycemia, and respiratory depression in the neonate. Monitor neonates for these effects.
Trimester-Specific Risks:
First Trimester:
Limited human data, animal studies show some adverse effects at high doses. Risk of congenital malformations not clearly established.
Second Trimester:
Potential for fetal growth restriction, bradycardia, and hypoglycemia.
Third Trimester:
Increased risk of neonatal bradycardia, hypoglycemia, respiratory depression, and prolonged labor.
Lactation
Metoprolol is excreted in breast milk. The amount is small, and adverse effects in breastfed infants are unlikely, but monitor for signs of beta-blockade (e.g., bradycardia, drowsiness, poor feeding). Considered L3 (Moderately Safe) by some sources.
Infant Risk:
Low to moderate; monitor for bradycardia, hypotension, and hypoglycemia.
Pediatric Use
Safety and efficacy not established for routine pediatric use in hypertension. Limited data for specific conditions (e.g., hypertrophic cardiomyopathy, certain arrhythmias). Dosing is typically weight-based and off-label. Close monitoring is required.
Geriatric Use
Start with lower doses and titrate slowly due to increased sensitivity to beta-blockers and potential for reduced renal/hepatic function. Increased risk of adverse effects like bradycardia, hypotension, and CNS effects. Monitor closely for dizziness and falls.
Clinical Information
Clinical Pearls
- Always emphasize the importance of not stopping metoprolol abruptly, especially in patients with coronary artery disease, due to the risk of rebound angina or myocardial infarction.
- Metoprolol tartrate (Lopressor) is immediate-release and typically dosed twice daily, whereas metoprolol succinate (Toprol XL) is extended-release and dosed once daily. Ensure patients understand which formulation they are taking.
- Beta-blockers can mask symptoms of hypoglycemia in diabetic patients (e.g., tremor, palpitations), but sweating may still occur.
- Use with caution in patients with asthma or severe COPD, as beta-1 selectivity may be lost at higher doses, leading to bronchospasm.
- Monitor for signs of worsening heart failure, especially during initiation or dose titration, as beta-blockers can initially worsen symptoms in some patients before providing long-term benefits.
Alternative Therapies
- Other beta-blockers (e.g., atenolol, carvedilol, bisoprolol)
- ACE inhibitors (e.g., lisinopril, enalapril)
- Angiotensin Receptor Blockers (ARBs) (e.g., valsartan, losartan)
- Calcium Channel Blockers (e.g., amlodipine, nifedipine, diltiazem, verapamil)
- Thiazide diuretics (e.g., hydrochlorothiazide)
- Alpha-blockers (e.g., prazosin, doxazosin)
- Direct vasodilators (e.g., hydralazine, minoxidil)
Cost & Coverage
Average Cost:
$10 - $30 per 30 tablets (generic 100mg)
Generic Available:
Yes
Insurance Coverage:
Tier 1 (preferred generic)
General Drug Facts
If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about this medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When seeking help, be prepared to provide details about the overdose, including the medication taken, the amount, and the time it occurred.