Metoprolol Tartrate

Class: beta-Adrenergic Blocking Agents
Note: This monograph also contains information on Metoprolol Succinate
VA Class: CV100
Molecular Formula: C₂₂H₂₃ClN₆O•K ½C₄H₄ O₄
CAS Number: 98418-47-4
Brands: Toprol XL, Lopressor, Lopressor HCT

Introduction

β₁-Selective adrenergic blocking agent.^{109 147 281}

Uses for Metoprolol Tartrate

Hypertension

Management of hypertension (alone or in combination with other classes of antihypertensive agents).^{100 111 157 160 161}

One of several preferred initial therapies in hypertensive patients with ischemic heart disease, heart failure, or diabetes mellitus.²³²

Can be used as monotherapy for initial management of uncomplicated hypertension; however, thiazide diuretics are preferred by JNC 7.²³²

Angina

Management of chronic stable angina pectoris.^{109 147}

A component of the standard therapeutic measures in the management of unstable angina or non-ST-segment elevation/non-Q-wave MI.^{158 218 219 281}

AMI

Secondary prevention following AMI to reduce the risk of reinfarction and mortality.^{109 123 124 126 127 144 158 281}

Supraventricular Tachyarrhythmias

β-Adrenergic blocking agents, including metoprolol, are one of several preferred antiarrhythmic agents for the treatment of stable, narrow-complex supraventricular tachycardias (e.g., paroxysmal supraventricular tachycardia† [reentry supraventricular tachycardia], ectopic† or multifocal atrial tachycardia†, junctional tachycardia†) if the rhythm is not controlled by vagal maneuvers or adenosine in patients with preserved left ventricular function and for rate control in atrial fibrillation or flutter† in patients with preserved left ventricular function.²⁸¹

Ventricular Tachyarrhythmias

Reduction of the incidence of ventricular fibrillation† associated with myocardial ischemia or infarction.^{158 197 281}

Treatment of sustained polymorphic ventricular tachycardia† following AMI.^{158 197}

CHF

Management of mild to moderately severe (NYHA class II or III) heart failure of ischemic, hypertensive, or cardiomyopathic origin (in conjunction with ACE inhibitors, diuretics, and cardiac glycosides).^{147 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 215 216}

Vascular Headache

Prophylaxis of migraine headache†; not recommended for the treatment of a migraine attack that has already started.²³¹

Metoprolol Tartrate Dosage and Administration

General

• 
  

  β₁-Adrenergic blocking selectivity diminishes as dosage is increased.^{109 147}

  
  


• 
  

  If long-term therapy is discontinued, reduce dosage gradually over a period of 1–2 weeks.^{109 147} (See Abrupt Withdrawal of Therapy under Cautions.)

  
  

Hypertension

• 
  

  Metoprolol/hydrochlorothiazide fixed combination is not recommended for initial combination therapy;¹⁵⁹ adjust initial and subsequent dosages by administering each drug separately.^a

  
  

Administration

Administer orally^{109 147} or by IV injection.¹⁰⁹

For ACLS during CPR, may be administered by intraosseous infusion†.²⁸¹

Oral Administration

Conventional Tablets

Administer metoprolol tartrate conventional tablets daily as a single dose or in divided doses, with or immediately following meals.¹⁰⁹

Extended-release Tablets

Administer metoprolol succinate extended-release tablets daily as a single dose.¹⁴⁷

Extended-release tablets are scored and can be divided.¹⁴⁷ However, swallow tablet or half tablet whole; do not chew or crush.¹⁴⁷

When switching from conventional tablets to extended-release tablets, administer the same daily dosage.¹⁴⁷

IV Administration

For solution and drug compatibility information, see Compatibility under Stability.

Monitor heart rate, BP, and ECG during IV therapy.¹⁵⁸

Discontinue IV therapy when therapeutic efficacy is achieved (e.g., slowing of ventricular rate in atrial fibrillation) or if systolic BP or heart rate declines to <100 mm Hg or 50 bpm, respectively.¹⁵⁸ Discontinue therapy in patients with severe intolerance to IV therapy.¹⁰⁹

Rate of Administration

Administer as a rapid IV injection.¹⁰⁹ Administer over 1–2 minutes for the management of unstable angina or non-ST-segment elevation/non-Q-wave MI†.²¹⁸

Dosage

Available as metoprolol tartrate and metoprolol succinate; dosage expressed in terms of the tartrate.^{109 147}

Pediatric Patients

Hypertension†

Oral

Some experts recommend an initial dosage of 1–2 mg/kg daily given in 2 divided doses.²⁶⁰ Increase dosage as necessary up to a maximum dosage of 6 mg/kg (up to 200 mg) daily given in 2 divided doses.²⁶⁰

Adults

Hypertension

Oral

Initially, 50–100 mg given once daily (extended-release tablets) or in single or divided doses daily (conventional tablets).^{109 147 232} Increase dosage at weekly (or longer) intervals until optimum effect is achieved.^{109 147}

If satisfactory BP response is not maintained throughout the day, larger doses, more frequent administration, or use of extended-release tablets may be required.^a

Angina

Long-term Management

Oral

Initially, 100 mg given once daily (extended-release tablets) or in 2 divided doses daily (conventional tablets).^{109 147} Increase dosage at weekly intervals until optimum response is obtained or pronounced slowing of heart rate occurs.^{109 147}

Usual maintenance dosage is 100–400 mg daily.¹⁰⁹

Unstable Angina or Non-ST-Segment Elevation MI†

IV, then Oral

Patients at high risk for ischemic events should receive IV loading dose followed by conversion to an oral regimen; oral therapy is recommended for lower risk patients.^{218 219}

5 mg IV every 5 minutes up to a total of 15 mg.²¹⁸ If IV dose is tolerated, 25–50 mg orally, initiated 15 minutes after the last IV dose and repeated every 6 hours for 48 hours, followed by 100 mg twice daily.²¹⁸ Target resting heart rate is 50–60 bpm in the absence of dose-limiting adverse effects.²¹⁸

AMI

As soon as clinical condition allows, administer oral therapy (conventional tablets) to patients who have contraindications to or do not tolerate IV therapy during the early phase of definite or suspected AMI or to patients in whom therapy is delayed.^a

Early Treatment.

IV, then Oral

2.5–5 mg IV every 2–5 minutes up to a total of 15 mg over 10–15 minutes.^a If total IV dose is tolerated, 50 mg orally, initiated 15 minutes after the last IV dose and repeated every 6 hours for 48 hours, followed by 100 mg twice daily.¹⁰⁹ If total IV dose is not tolerated, 25 or 50 mg (depending on the degree of intolerance) orally every 6 hours beginning 15 minutes after the last IV dose or as soon as clinical condition allows.¹⁰⁹

Late Treatment

Oral

100 mg twice daily for at least 3 months.¹⁰⁹

Supraventricular Tachyarrhythmias

Paroxysmal Supraventricular Tachycardia†, Junctional Tachycardia†, Ectopic Tachycardia†, Multifocal Atrial Tachycardia†

IV or Intraosseous

5 mg every 5 minutes, up to a total dose of 15 mg.²⁸¹

Atrial Fibrillation†.

IV, then Oral

2.5–5 mg IV every 2–5 minutes as necessary to control rate, up to a total of 15 mg over 10–15 minutes.^{158 197 203 281} Then, 25–100 mg orally twice daily for long-term control.²⁰³

Intraosseous

5 mg every 5 minutes, up to a total dose of 15 mg.²⁸¹

CHF

Oral

Initially, 25 mg (extended-release tablets) once daily in adults with NYHA class II heart failure.¹⁴⁷ In patients with more severe heart failure, use an initial dosage of 12.5 mg (extended-release tablets) once daily.¹⁴⁷ Double the dosage every 2 weeks to a dosage of 200 mg or until highest tolerated dosage is reached.¹⁴⁷

Some experts recommend initiation of therapy with 12.5 mg (extended-release tablets) daily or 6.25 mg (conventional tablets) twice daily for 2–4 weeks.^{163 173 205} If tolerated, increase to 25 mg daily for 2–4 weeks; subsequent dosages can be doubled every 2–4 weeks.^{163 147}

If deterioration occurs during titration, increase dosage of concurrent diuretic^{147 205} and decrease dosage of metoprolol or temporarily discontinue metoprolol.^{147 205} Do not continue dosage titration until symptoms of worsening heart failure have stabilized.^{147 205} Initial difficulty in dosage titration should not preclude subsequent attempts to successfully titrate the dosage.^{147 205}

Reduce dosage in patients with CHF who experience symptomatic bradycardia (e.g., dizziness) or 2nd or 3rd degree heart block.^{147 205}

Vascular Headache

Migraine†

Oral

Dosages of 50–300 mg daily have been used in clinical studies; usual effective dosage was 200 mg daily.²³¹

Prescribing Limits

Pediatric Patients

Hypertension†

Oral

Maximum 6 mg/kg (up to 200 mg) daily.²⁶⁰

Adults

Hypertension

Oral

Dosages >400 mg (extended-release tablets) and 450 mg (conventional tablets) daily have not been studied.^{109 147}

Angina

Oral

Dosages >400 mg daily have not been studied.^{109 147}

IV

Maximum 15 mg over 15 minutes in patients with unstable angina or non-ST-segment elevation MI†.²¹⁸

AMI

IV

Maximum 15 mg over 10–15 minutes.^a

Supraventricular Tachyarrhythmias

Atrial Fibrillation†.

Oral

Maximum 100 mg twice daily.²⁰³

IV

Maximum 15 mg over 10–15 minutes.^{158 203 281}

CHF

Oral

Up to 200 mg daily.¹⁴⁷

Special Populations

Hepatic Impairment

Elimination occurs mainly in the liver; dosage reductions may be necessary.^{109 a}

Renal Impairment

Dosage adjustments are not required.^{109 147}

Geriatric Patients

Cautious dosage selection recommended; initiate therapy at the lower end of the dosage range.¹⁴⁷

Cautions for Metoprolol Tartrate

Contraindications

• 
  

  Patients with sinus bradycardia, heart block greater than 1st degree, cardiogenic shock, overt or decompensated cardiac failure, or sick sinus syndrome (unless a permanent pacemaker is in place).^{109 147 159 281}

  
  


• 
  

  Patients with AMI who have a heart rate <45–60 bpm, heart block greater than 1st degree, systolic BP <100 mm Hg, or moderate to severe cardiac failure.^{109 281}

  
  

Warnings/Precautions

Warnings

Abrupt Withdrawal of Therapy

Abrupt discontinuance may exacerbate angina symptoms or precipitate MI in patients with CAD.^{109 147 a} Avoid abrupt discontinuance.^{109 147} Gradually decrease dosage over 1–2 weeks and monitor patients carefully.^{109 147} If exacerbation of angina occurs or acute coronary insufficiency develops, reinstitute therapy promptly, at least temporarily, and initiate appropriate measures for the management of unstable angina.^{109 147}

Cardiac Failure

Possible precipitation of CHF;¹⁰⁹ possible decreased exercise tolerance in patients with left ventricular dysfunction.^a

Initiate therapy and subsequent dosage adjustments in patients with CHF under close medical supervision.^{147 163 205} Prior to initiation of metoprolol, stabilize patient on other therapy (e.g., ACE inhibitor, diuretic, and/or cardiac glycoside).^{147 163 205} Symptomatic improvement may not be evident for 2–3 months after initiating therapy.^{163 205}

Avoid use in patients with decompensated CHF;^{147 a} use cautiously in patients with inadequate myocardial function and, if necessary, in patients with well-compensated heart failure (e.g., those controlled with ACE inhibitors, cardiac glycosides, and/or diuretics);^{147 a} use with extreme caution in patients with substantial cardiomegaly.^a

Adequate treatment (e.g., with a cardiac glycoside and/or diuretic) and close observation recommended if signs or symptoms of impending cardiac failure occur; if cardiac failure continues, discontinue therapy, gradually if possible.^{109 147}

Bronchospastic Disease

Possible bronchoconstriction, especially at dosages >100 mg daily.^{109 a}

Use with caution in patients with bronchospastic disease; administer lowest effective dosage (initially in 3 divided doses) and with maximal therapy with a β₂-adrenergic agonist.^{109 a}

Bradycardia

Possible bradycardia and depressed SA node automaticity.^{109 147 a}

Carefully monitor hemodynamic status of patients with MI; use with caution in patients with sinus node dysfunction.^{109 147 a}

If heart rate < 40 bpm with evidence of decreased cardiac output, administer IV atropine; if bradycardia is refractory to atropine, discontinue metoprolol and consider cautious administration of isoproterenol or use of a cardiac pacemaker.^{109 281}

AV Block

Possible intensification of AV block, AV dissociation, AV conduction delays,²⁸¹ complete heart block, or cardiac arrest, especially in patients with preexisting heart block caused by digoxin or other factors.^{109 a}

Use with caution, if at all, in patients with AV conduction defects.^a

If heart block occurs in patients with MI, discontinue metoprolol and administer IV atropine; if the heart block is refractory to atropine, consider cautious administration of isoproterenol or use of a cardiac pacemaker.¹⁰⁹

Hypotension

If hypotension (systolic BP <90 mm Hg) occurs in patients with MI, discontinue metoprolol and assess hemodynamic status and extent of myocardial damage.¹⁰⁹ Invasive monitoring of central venous, pulmonary capillary wedge, and arterial pressures may be necessary; appropriate therapy with IV fluids and other treatment modalities recommended.¹⁰⁹

If hypotension is associated with severe bradycardia or heart block, provide treatment directed at reversing these.¹⁰⁹ (See Bradycardia and also see AV Block under Cautions.)

Major Surgery

Possible increased risks associated with general anesthesia (e.g., severe hypotension, maintenance of heart beat) due to decreased ability of the heart to respond to reflex β-adrenergic stimuli.^{109 147}

Use with caution in patients undergoing major surgery involving general anesthesia; avoid use of anesthetics that cause myocardial depression (see Specific Drugs under Interactions).^a

Diabetes and Hypoglycemia

Possible decreased signs and symptoms of hypoglycemia (e.g., tachycardia, palpitation, BP changes, tremor, feelings of anxiety) and increased insulin-induced hypoglycemia.^{109 147 a}

Use with caution in patients with diabetes mellitus.^{109 147}

Thyrotoxicosis

Signs of hyperthyroidism (e.g., tachycardia) may be masked.^{109 147} Possible thyroid storm if therapy is abruptly withdrawn; carefully monitor patients having or suspected of developing thyrotoxicosis.^{109 147}

General Precautions

Ocular Effects

Possible dry eyes and decreased tear production, minimal injection of conjunctivae and/or eyelids, punctate keratitis, keratoconjunctivitis or corneal ulceration.^a Close observation recommended.^a

Possible Prescribing and Dispensing Errors

Ensure accuracy of prescription; similarity in spelling between Toprol-XL (metoprolol succinate) and Topamax (trade name for topiramate, an anticonvulsant and antimigraine agent) may result in errors.^{261 262 263 264}

Potential also exists for dispensing errors involving confusion between Toprol-XL and Tegretol or Tegretol-XR (trade names for carbamazepine, an anticonvulsant also used for relief of pain associated with trigeminal neuralgia, as well as for various psychiatric disorders).^{261 263}

These medication errors have been associated with serious adverse events sometimes requiring hospitalization as a result of either lack of the intended medication (e.g., seizure recurrence, return of hallucinations, suicide attempt, hypertension recurrence) or exposure to the wrong drug (e.g., bradycardia in a patient erroneously receiving metoprolol).^{261 262 263 264 261 262 263 264}

Use of Fixed Combinations

When used in fixed combination with hydrochlorothiazide, consider the cautions, precautions, and contraindications associated with hydrochlorothiazide.^a

Specific Populations

Pregnancy

Category C.^{109 147}

Lactation

Distributed into milk.¹⁴⁷ Use with caution.¹⁰⁹

Pediatric Use

Safety and efficacy remain to be fully established in children;^{109 147} however, some experts have recommended dosages for hypertension based on current limited clinical experience.²⁵⁸

Geriatric Use

Among patients with heart failure, safety and efficacy profiles in geriatric individuals are similar to those in younger adults.¹⁴⁷

BP determinations recommended in both the seated position and after patient stands quietly for 2–5 minutes (to recognize postural hypotension).¹⁶⁰

Hepatic Impairment

Hepatic elimination; use with caution.^{109 147 a}

Common Adverse Effects

Dizziness, tiredness, insomnia, gastric upset.^a

Interactions for Metoprolol Tartrate

Metabolized by CYP2D6.^{147 200 201 202 208 210 211}

Drugs Affecting Hepatic Microsomal Enzymes

CYP2D6 inhibitors: Potential pharmacodynamic (increased β-adrenergic blockade, decreased cardioselectivity of metoprolol) and pharmacokinetic interaction (prolonged half-life and increased plasma concentrations of metoprolol).^{147 200 201 202 208 210 211}

Specific Drugs

Drug	Interaction	Comments
Calcium-channel blocking agents, nondihydropyridine	Possible additive negative effects on SA or AV nodal conductiona
Digoxin	Possible additive negative effects on SA or AV nodal conductiona
Diuretics	Increased hypotensive effecta	Adjust dosage carefullya
Fluoxetine	Possible increased plasma metoprolol concentrations; potential for increased β-adrenergic blockade and decreased cardioselectivity of metoprolol147 200 201 202 208 210 211
Anesthetics, general (myocardial depressant agents [e.g., diethyl ether])	Increased risk of hypotension and heart failure109	Avoid use of general anesthetics with myocardial depressant effectsa
Hydralazine	Increased risk of pulmonary hypertension in patients with uremia a
Hypotensive agents	Possible increased hypotensive effecta	Adjust dosage carefullya
Paroxetine	Possible increased plasma metoprolol concentrations; potential for increased β-adrenergic blockade and decreased cardioselectivity of metoprolol147 200 201 202 208 210 211	Use with caution209 211 212
Propafenone	Possible increased plasma metoprolol concentrations; potential for increased β-adrenergic blockade and decreased cardioselectivity of metoprolol147 200 201 202 208 210 211
Quinidine	Possible increased plasma metoprolol concentrations; potential for increased β-adrenergic blockade and decreased cardioselectivity of metoprolol147 200 201 202 208 210 211
Reserpine	Additive effects109	Monitor for hypotension and bradycardia109
Sertraline	Possible increased plasma metoprolol concentrations; potential for increased β-adrenergic blockade and decreased cardioselectivity of metoprolol147 200 201 202 208 210 211	When concomitant sertraline therapy is discontinued, may need to increase metoprolol dosage208
Sympathomimetic agents	Antagonism of β1-adrenergic stimulating effectsa
Verapamil	Increased oral bioavailability105 106	Avoid concomitant use, if possible;105 106 if used concomitantly, adjust metoprolol dosage and monitor patient closely106

Metoprolol Tartrate Pharmacokinetics

Absorption

Bioavailability

Metoprolol tartrate is rapidly and almost completely absorbed from the GI tract.¹⁰⁹ After an oral dose (as conventional tablets), about 50% of the drug undergoes first-pass metabolism in the liver.¹⁰⁹

Peak plasma concentrations are reached in about 90 minutes following a single oral dose as conventional tablets^a or 7 hours following administration as extended-release tablets.¹⁴⁸

Steady-state oral bioavailability of extended-release tablets given once daily is about 77% of that of conventional tablets at corresponding dosages.^{147 148} Following oral administration as extended-release tablets, peak plasma metoprolol concentrations are about 25–50% of those attained after administration of conventional tablets.¹⁴⁷

Plasma concentrations attained after IV administration are approximately twice those attained following oral administration.^a

Onset

Reduction in systolic BP during exercise reported within 15 minutes after a single oral dose of metoprolol tartrate 50–80 mg; with chronic therapy, effect on systolic BP usually is maximal within 1 week.^a

The extended-release tablets, given once daily, produce similar hypotensive effects as conventional tablets at similar dosages.^{147 148}

Maximum β-adrenergic blocking activity occurs at 20 minutes after a 10-minute IV infusion.¹⁰⁹

Duration

Reduction in systolic BP during exercise persisted for 6 hours following a single oral dose of metoprolol tartrate 50–80 mg.^a Hypotensive effect of extended-release tablets may persist for 24 hours.¹⁴⁷ Duration of β-adrenergic blocking effect is dose related.¹⁰⁹

Following IV infusion of metoprolol tartrate 5 or 15 mg, β-adrenergic blocking activity persisted for approximately 5 or 8 hours, respectively.¹⁰⁹

Food

Food does not affect bioavailability of extended-release tablets.¹⁴⁷

When conventional tablets are administered with food, peak plasma concentrations are higher and the extent of absorption is increased.^a

Distribution

Extent

Widely distributed into body tissues.^a Concentrations in heart, liver, lungs, and saliva exceed plasma concentration.^a Crosses the blood-brain barrier;¹⁴⁷ concentration in CSF is about 78% of the simultaneous plasma concentration.^a

Crosses the placenta.^a

Concentration in milk is about 3–4 times the maternal plasma concentrations, but the actual amount distributed into milk appears to be very small.^{101 102}

Plasma Protein Binding

11–12% (albumin).¹⁰⁹

Elimination

Metabolism

Undergoes first-pass metabolism in the liver by CYP2D6 to inactive metabolites.^{109 147}

Elimination Route

Excreted in urine, principally as metabolites.¹⁰⁹

Half-life

3–4 hours.¹⁰⁹

Special Populations

Half-life does not increase appreciably with impaired renal function.¹⁰⁹

Half-life is about 7.6 hours in poor metabolizers of the drug.^a Concomitant use of CYP2D6 inhibitors (see Drugs Affecting Hepatic Microsomal Enzymes under Interactions) in poor metabolizers will lead to increases in plasma metoprolol concentrations and a decrease in β₁-selectivity.¹⁴⁷

Stability

Storage

Oral

Tablets

Tight, light-resistant containers at 15–30°C.¹⁰⁹ Protect from light.¹⁰⁹

Extended-Release Tablets

25°C (may be exposed to 15–30°C).¹⁴⁷

Parenteral

Injection

30°C or less (preferably 15–30°C).¹⁰⁹ Protect from light¹⁰⁹ and freezing.^a

Compatibility

For information on systemic interactions resulting from concomitant use, see Interactions.

Parenteral

Solution Compatibility^HID

Compatible
Dextrose 5% in water
Sodium chloride 0.9%

Drug Compatibility

Y-Site CompatibilityHID

Compatible
Abciximab
Alteplase
Argatroban
Meperidine HCl
Morphine sulfate
Incompatible
Amphotericin B cholesteryl sulfate complex

ActionsActions

• 
  

  Inhibits response to adrenergic stimuli by competitively blocking β₁-adrenergic receptors within the myocardium.^{109 147} Blocks β₂-adrenergic receptors within bronchial and vascular smooth muscle only in high doses.^{109 147}

  
  


• 
  

  Decreases resting heart rate, reflex orthostatic tachycardia, myocardial contractility, and cardiac output at rest and during exercise (without increasing peripheral resistance); inhibits exercise-induced increases in heart rate; increases systolic ejection time and cardiac volume, without changing stroke volume; decreases conduction velocity through the SA and AV nodes; and decreases myocardial automaticity.^{109 147 a}

  
  


• 
  

  No intrinsic sympathomimetic activity and little or no membrane-stabilizing effect on the heart.^{109 147}

  
  


• 
  

  Reduces BP by decreasing cardiac output, decreasing sympathetic outflow from the CNS, suppressing renin release, and/or reducing peripheral resistance.^{109 147 a}

  
  


• 
  

  In patients with MI, reduces heart rate, systolic BP, cardiac output, and ventricular fibrillation.^{109 a}

  
  


• 
  

  In patients with angina, blocks catecholamine-induced increases in heart rate, velocity and extent of myocardial contraction, and BP, resulting in decreased myocardial oxygen consumption.^{109 147}

  
  


• 
  

  Increases airway resistance and decreases ventilatory capacity in asthmatic patients.^{109 147 a}

  
  


• 
  

  Causes little inhibition of glycogenolysis in skeletal and cardiac muscles; inhibits increase in plasma glycerol during exercise; inhibits insulin release less than propranolol.^a

  
  

Advice to Patients

• 
  

  Importance of taking metoprolol exactly as prescribed.²¹⁴

  
  


• 
  

  Importance of not interrupting or discontinuing therapy without consulting clinician; patients should temporarily limit their physical activity when discontinuing therapy.^{109 147}

  
  


• 
  

  If a dose is missed, importance of patient taking only the next scheduled dose (i.e., the next dose should not be doubled).^{109 147}

  
  


• 
  

  Importance of immediately informing clinician at the first sign or symptom of impending cardiac failure (e.g., weight gain, increased shortness of breath) or if any difficulty in breathing occurs.¹⁰⁹

  
  


• 
  

  In patients with heart failure, importance of informing clinician of signs or symptoms of exacerbation (e.g., weight gain, difficulty in breathing).¹⁴⁷

  
  


• 
  

  Importance of patients informing anesthesiologist or dentist that they are receiving metoprolol therapy prior to undergoing major surgery.^{109 147}

  
  


• 
  

  Importance of avoiding some activities (e.g., operating machinery, driving a motor vehicle) until effects on individual are known.^{109 147}

  
  


• 
  

  Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs.^{109 147 159}

  
  


• 
  

  Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.¹⁰⁹

  
  


• 
  

  Importance of informing patients of other important precautionary information.^{109 147} (See Cautions.)

  
  

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

Metoprolol Succinate

Routes	Dosage Forms	Strengths	Brand Names	Manufacturer
Oral	Tablets, extended-release, film-coated	23.75 mg (equivalent to 25 mg of metoprolol tartrate)	Toprol XL (scored)	AstraZeneca
		47.5 mg (equivalent to 50 mg of metoprolol tartrate)	Toprol XL (scored)	AstraZeneca
		95 mg (equivalent to 100 mg of metoprolol tartrate)	Toprol XL (scored)	AstraZeneca
		190 mg (equivalent to 200 mg of metoprolol tartrate)	Toprol XL (scored)	AstraZeneca

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

Metoprolol Tartrate

Routes	Dosage Forms	Strengths	Brand Names	Manufacturer
Oral	Tablets	50 mg*	Lopressor (scored)	Novartis
			Metoprolol Tartrate Tablets
		100 mg*	Lopressor (scored)	Novartis
			Metoprolol Tartrate Tablets
Parenteral	Injection	1 mg/mL	Lopressor	Novartis
			Metoprolol Tartrate Injection

Metoprolol Tartrate and Hydrochlorothiazide

Routes	Dosage Forms	Strengths	Brand Names	Manufacturer
Oral	Tablets	50 mg Metoprolol Tartrate and Hydrochlorothiazide 25 mg	Lopressor HCT (scored)	Novartis
		100 mg Metoprolol Tartrate and Hydrochlorothiazide 25 mg	Lopressor HCT (scored)	Novartis
		100 mg Metoprolol Tartrate and Hydrochlorothiazide 50 mg	Lopressor HCT (scored)	Novartis

Comparative Pricing

This pricing information is subject to change at the sole discretion of DS Pharmacy. This pricing information was updated 03/2011. Actual costs to patients will vary depending on the use of specific retail or mail-order locations and health insurance copays.

Lopressor 100MG Tablets (NOVARTIS): 60/$162.98 or 180/$488.95

Lopressor 50MG Tablets (NOVARTIS): 60/$118.99 or 180/$327.99

Lopressor HCT 100-50MG Tablets (NOVARTIS): 30/$81.99 or 90/$224.97

Metoprolol Tartrate 25MG Tablets (MYLAN): 30/$12.99 or 60/$14.98

Metoprolol-Hydrochlorothiazide 100-25MG Tablets (MYLAN): 30/$49.99 or 90/$129.97

Metoprolol-Hydrochlorothiazide 100-50MG Tablets (MYLAN): 30/$55.99 or 90/$149.97

Metoprolol-Hydrochlorothiazide 50-25MG Tablets (MYLAN): 60/$60.97 or 180/$160.97

Toprol XL 100MG 24-hr Tablets (ASTRAZENECA LP): 30/$59.99 or 90/$155.97

Toprol XL 200MG 24-hr Tablets (ASTRAZENECA LP): 90/$266.98 or 180/$507.97

Toprol XL 25MG 24-hr Tablets (ASTRAZENECA LP): 30/$45.99 or 90/$109.97

Toprol XL 50MG 24-hr Tablets (ASTRAZENECA LP): 30/$44.99 or 90/$109.97

Disclaimer

This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmacist about specific clinical use.

The American Society of Health-System Pharmacists, Inc. and Drugs.com represent that the information provided hereunder was formulated with a reasonable standard of care, and in conformity with professional standards in the field. The American Society of Health-System Pharmacists, Inc. and Drugs.com make no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to such information and specifically disclaims all such warranties. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information is provided for informational purposes only. The entire monograph for a drug should be reviewed for a thorough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists, Inc. and Drugs.com do not endorse or recommend the use of any drug. The information is not a substitute for medical care.

AHFS Drug Information. © Copyright, 1959-2011, Selected Revisions September 2009. American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland 20814.

† Use is not currently included in the labeling approved by the US Food and Drug Administration.

References

Only references cited for selected revisions after 1984 are available electronically.

100. Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure. The 1984 report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure. Arch Intern Med. 1984; 144:1045-57. [IDIS 184763] [PubMed 6143542]

101. Sandström B, Regardh CG. Metoprolol excretion into milk. Br J Clin Pharmacol. 1980; 9:518-9. [IDIS 114928] [PubMed 7397065]

102. Liedholm H, Melander A, Bitzén PO et al. Accumulation of atenolol and metoprolol in human breast milk. Eur J Clin Pharmacol. 1981; 20:229-31. [IDIS 148916] [PubMed 7286041]

103. Searle & Co. Calan SR prescribing information. Chicago; 1986 Nov.

104. Searle & Co. Calan prescribing information. Chicago, IL; 1986 Nov.

105. McLea