Lopressor

LOPRESSOR - metoprolol tartrate tablet
LOPRESSOR - metoprolol tartrate injection, solution
Novartis Pharmaceuticals Corporation
metoprolol tartrate tablets, USP
metoprolol tartrate injection, USP
Rx only
Prescribing Information
DESCRIPTION
Lopressor, metoprolol tartrate USP, is a selective beta1-adrenoreceptor blocking agent, available as 50- and 100-mg tablets for oral
administration and in 5-mL ampuls for intravenous administration. Each ampul contains a sterile solution of metoprolol tartrate USP,
5 mg, and sodium chloride USP, 45 mg, and water for injection USP. Metoprolol tartrate USP is (±)-1-(Isopropylamino)-3-[p-(2-
methoxyethyl)phenoxy]-2-propanol L-(+)-tartrate (2:1) salt, and its structural formula is
Metoprolol tartrate USP is a white, practically odorless, crystalline powder with a molecular weight of 684.82. It is very soluble inwater; freely soluble in methylene chloride, in chloroform, and in alcohol; slightly soluble in acetone; and insoluble in ether.
Inactive Ingredients: Tablets contain cellulose compounds, colloidal silicon dioxide, D&C Red No. 30 aluminum lake (50-mg tablets),FD&C Blue No. 2 aluminum lake (100-mg tablets), lactose, magnesium stearate, polyethylene glycol, propylene glycol, povidone,sodium starch glycolate, talc, and titanium dioxide.
CLINICAL PHARMACOLOGY
Lopressor is a beta-adrenergic receptor blocking agent. In vitro and in vivo animal studies have shown that it has a preferential effect
on beta1 adrenoreceptors, chiefly located in cardiac muscle. This preferential effect is not absolute, however, and at higher doses,
Lopressor also inhibits beta2 adrenoreceptors, chiefly located in the bronchial and vascular musculature.
Clinical pharmacology studies have confirmed the beta-blocking activity of metoprolol in man, as shown by (1) reduction in heart rate
and cardiac output at rest and upon exercise, (2) reduction of systolic blood pressure upon exercise, (3) inhibition of isoproterenol-
induced tachycardia, and (4) reduction of reflex orthostatic tachycardia.
Relative beta1 selectivity has been confirmed by the following: (1) In normal subjects, Lopressor is unable to reverse the beta2-
mediated vasodilating effects of epinephrine. This contrasts with the effect of nonselective (beta1 plus beta2) beta blockers, which
completely reverse the vasodilating effects of epinephrine. (2) In asthmatic patients, Lopressor reduces FEV1 and FVC significantly
less than a nonselective beta blocker, propranolol, at equivalent beta1-receptor blocking doses.
Lopressor has no intrinsic sympathomimetic activity, and membrane-stabilizing activity is detectable only at doses much greater than
required for beta blockade. Lopressor crosses the blood-brain barrier and has been reported in the CSF in a concentration 78% of the
simultaneous plasma concentration. Animal and human experiments indicate that Lopressor slows the sinus rate and decreases AV
nodal conduction.
In controlled clinical studies, Lopressor has been shown to be an effective antihypertensive agent when used alone or as concomitant
therapy with thiazide-type diuretics, at dosages of 100-450 mg daily. In controlled, comparative, clinical studies, Lopressor has been
shown to be as effective an antihypertensive agent as propranolol, methyldopa, and thiazide-type diuretics, and to be equally effective
in supine and standing positions.
The mechanism of the antihypertensive effects of beta-blocking agents has not been elucidated. However, several possible
mechanisms have been proposed: (1) competitive antagonism of catecholamines at peripheral (especially cardiac) adrenergic neuron
sites, leading to decreased cardiac output; (2) a central effect leading to reduced sympathetic outflow to the periphery; and (3)
suppression of renin activity.
By blocking catecholamine-induced increases in heart rate, in velocity and extent of myocardial contraction, and in blood pressure,
Lopressor reduces the oxygen requirements of the heart at any given level of effort, thus making it useful in the long-term
management of angina pectoris. However, in patients with heart failure, beta-adrenergic blockade may increase oxygen requirements
by increasing left ventricular fiber length and end-diastolic pressure.
Although beta-adrenergic receptor blockade is useful in the treatment of angina and hypertension, there are situations in which
sympathetic stimulation is vital. In patients with severely damaged hearts, adequate ventricular function may depend on sympathetic
drive. In the presence of AV block, beta blockade may prevent the necessary facilitating effect of sympathetic activity on conduction.
Beta2-adrenergic blockade results in passive bronchial constriction by interfering with endogenous adrenergic bronchodilator activity
in patients subject to bronchospasm and may also interfere with exogenous bronchodilators in such patients.
In controlled clinical trials, Lopressor, administered two or four times daily, has been shown to be an effective antianginal agent,reducing the number of angina attacks and increasing exercise tolerance. The dosage used in these studies ranged from 100-400 mgdaily. A controlled, comparative, clinical trial showed that Lopressor was indistinguishable from propranolol in the treatment ofangina pectoris.
In a large (1,395 patients randomized), double-blind, placebo-controlled clinical study, Lopressor was shown to reduce 3-monthmortality by 36% in patients with suspected or definite myocardial infarction.
Patients were randomized and treated as soon as possible after their arrival in the hospital, once their clinical condition had stabilizedand their hemodynamic status had been carefully evaluated. Subjects were ineligible if they had hypotension, bradycardia, peripheralsigns of shock, and/or more than minimal basal rales as signs of congestive heart failure. Initial treatment consisted of intravenousfollowed by oral administration of Lopressor or placebo, given in a coronary care or comparable unit. Oral maintenance therapy withLopressor or placebo was then continued for 3 months. After this double-blind period, all patients were given Lopressor and followedup to 1 year.
The median delay from the onset of symptoms to the initiation of therapy was 8 hours in both the Lopressor- and placebo-treatmentgroups. Among patients treated with Lopressor, there were comparable reductions in 3-month mortality for those treated early(≤8 hours) and those in whom treatment was started later. Significant reductions in the incidence of ventricular fibrillation and in chestpain following initial intravenous therapy were also observed with Lopressor and were independent of the interval between onset ofsymptoms and initiation of therapy.
The precise mechanism of action of Lopressor in patients with suspected or definite myocardial infarction is not known.
In this study, patients treated with metoprolol received the drug both very early (intra-venously) and during a subsequent 3-monthperiod, while placebo patients received no beta-blocker treatment for this period. The study thus was able to show a benefit fromthe overall metoprolol regimen but cannot separate the benefit of very early intravenous treatment from the benefit of later beta-blocker therapy. Nonetheless, because the overall regimen showed a clear beneficial effect on survival without evidence of an earlyadverse effect on survival, one acceptable dosage regimen is the precise regimen used in the trial. Because the specific benefit ofvery early treatment remains to be defined however, it is also reasonable to administer the drug orally to patients at a later time as isrecommended for certain other beta blockers.
Pharmacokinetics
In man, absorption of Lopressor is rapid and complete. Plasma levels following oral administration, however, approximate 50% of
levels following intravenous administration, indicating about 50% first-pass metabolism.
Plasma levels achieved are highly variable after oral administration. Only a small fraction of the drug (about 12%) is bound to human
serum albumin. Metoprolol is a racemic mixture of R- and S-enantiomers. Less than 5% of an oral dose of Lopressor is recovered
unchanged in the urine; the rest is excreted by the kidneys as metabolites that appear to have no clinical significance. The systemic
availability and half-life of Lopressor in patients with renal failure do not differ to a clinically significant degree from those in normal
subjects. Consequently, no reduction in dosage is usually needed in patients with chronic renal failure.
Lopressor is extensively metabolized by the cytochrome P450 enzyme system in the liver. The oxidative metabolism of Lopressor
is under genetic control with a major contribution of the polymorphic cytochrome P450 isoform 2D6 (CYP2D6). There are marked
ethnic differences in the prevalence of the poor metabolizers (PM) phenotype. Approximately 7% of Caucasians and less than 1%
Asian are poor metabolizers.
Poor CYP2D6 metabolizers exhibit several-fold higher plasma concentrations of Lopressor than extensive metabolizers with
normal CYP2D6 activity. The elimination half-life of metoprolol is about 7.5 hours in poor metabolizers and 2.8 hours in extensive
metabolizers. However, the CYP2D6 dependent metabolism of Lopressor seems to have little or no effect on safety or tolerability of
the drug. None of the metabolites of Lopressor contribute significantly to its beta-blocking effect.
Significant beta-blocking effect (as measured by reduction of exercise heart rate) occurs within 1 hour after oral administration, and its
duration is dose-related. For example, a 50% reduction of the maximum registered effect after single oral doses of 20, 50, and 100 mg
occurred at 3.3, 5.0, and 6.4 hours, respectively, in normal subjects. After repeated oral dosages of 100 mg twice daily, a significant
reduction in exercise systolic blood pressure was evident at 12 hours.
Following intravenous administration of Lopressor, the urinary recovery of unchanged drug is approximately 10%. When the drug
was infused over a 10-minute period, in normal volunteers, maximum beta blockade was achieved at approximately 20 minutes. Doses
of 5 mg and 15 mg yielded a maximal reduction in exercise-induced heart rate of approximately 10% and 15%, respectively. The
effect on exercise heart rate decreased linearly with time at the same rate for both doses, and disappeared at approximately 5 hours and
8 hours for the 5-mg and 15-mg doses, respectively.
Equivalent maximal beta-blocking effect is achieved with oral and intravenous doses in the ratio of approximately 2.5:1.
There is a linear relationship between the log of plasma levels and reduction of exercise heart rate. However, antihypertensive activity
does not appear to be related to plasma levels. Because of variable plasma levels attained with a given dose and lack of a consistent
relationship of antihypertensive activity to dose, selection of proper dosage requires individual titration.
In several studies of patients with acute myocardial infarction, intravenous followed by oral administration of Lopressor caused a
reduction in heart rate, systolic blood pressure, and cardiac output. Stroke volume, diastolic blood pressure, and pulmonary artery end
diastolic pressure remained unchanged.
In patients with angina pectoris, plasma concentration measured at 1 hour is linearly related to the oral dose within the range of
50-400 mg. Exercise heart rate and systolic blood pressure are reduced in relation to the logarithm of the oral dose of metoprolol. The
increase in exercise capacity and the reduction in left ventricular ischemia are also significantly related to the logarithm of the oraldose.
In elderly subjects with clinically normal renal and hepatic function, there are no significant differences in Lopressorpharmacokinetics compared to young subjects.
INDICATIONS AND USAGE
Hypertension
Lopressor tablets are indicated for the treatment of hypertension. They may be used alone or in combination with other
antihypertensive agents.
Angina Pectoris
Lopressor is indicated in the long-term treatment of angina pectoris.
Myocardial Infarction
Lopressor ampuls and tablets are indicated in the treatment of hemodynamically stable patients with definite or suspected acute
myocardial infarction to reduce cardiovascular mortality. Treatment with intravenous Lopressor can be initiated as soon as the
patient’s clinical condition allows (see DOSAGE AND ADMINISTRATION, CONTRAINDICATIONS, and WARNINGS).
Alternatively, treatment can begin within 3 to 10 days of the acute event (see DOSAGE AND ADMINISTRATION).
CONTRAINDICATIONS
Hypertension and Angina
Lopressor is contraindicated in sinus bradycardia, heart block greater than first degree, cardiogenic shock, and overt cardiac failure
(see WARNINGS).
Hypersensitivity to Lopressor and related derivatives, or to any of the excipients; hypersensitivity to other beta blockers (cross
sensitivity between beta blockers can occur).
Sick-sinus syndrome.
Severe peripheral arterial circulatory disorders.
Myocardial Infarction
Lopressor is contraindicated in patients with a heart rate <45 beats/min; second- and third-degree heart block; significant first-degree
heart block (P-R interval ≥0.24 sec); systolic blood pressure <100 mmHg; or moderate-to-severe cardiac failure (see WARNINGS).
WARNINGS
Hypertension and Angina
Cardiac Failure: Sympathetic stimulation is a vital component supporting circulatory function in congestive heart failure, and
beta blockade carries the potential hazard of further depressing myocardial contractility and precipitating more severe failure.
In hypertensive and angina patients who have congestive heart failure controlled by digitalis and diuretics, Lopressor should be
administered cautiously.
In Patients Without a History of Cardiac Failure: Continued depression of the myocardium with beta-blocking agents over a
period of time can, in some cases, lead to cardiac failure. At the first sign or symptom of impending cardiac failure, patients should
be fully digitalized and/or given a diuretic. The response should be observed closely. If cardiac failure continues, despite adequate
digitalization and diuretic therapy, Lopressor should be withdrawn.
Ischemic Heart Disease: 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 Lopressor,
particularly in patients with ischemic heart disease, the dosage should be gradually reduced over a period of 1-2 weeks and
the patient should be carefully monitored. If angina markedly worsens or acute coronary insufficiency develops, Lopressor
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 Lopressor therapy abruptly even in patients treated only for hypertension.

Bronchospastic Diseases: PATIENTS WITH BRONCHOSPASTIC DISEASES SHOULD, IN GENERAL, NOT RECEIVE
BETA BLOCKERS, including Lopressor. Because of its relative beta1 selectivity, however, Lopressor may be used with
caution in patients with bronchospastic disease who do not respond to, or cannot tolerate, other antihypertensive treatment.
Since beta1 selectivity is not absolute, a beta2-stimulating agent should be administered concomitantly, and the lowest possible
dose of Lopressor should be used. In these circumstances it would be prudent initially to administer Lopressor in smaller
doses three times daily, instead of larger doses two times daily, to avoid the higher plasma levels associated with the longer
dosing interval (see DOSAGE AND ADMINISTRATION).
Major Surgery: Chronically administered beta-blocking therapy should not be routinely withdrawn prior to major surgery; however,
the impaired ability of the heart to respond to reflex adrenergic stimuli may augment the risks of general anesthesia and surgical
procedures.
Diabetes and Hypoglycemia: Lopressor should be used with caution in diabetic patients if a beta-blocking agent is required. Beta
blockers may mask tachycardia occurring with hypoglycemia, but other manifestations such as dizziness and sweating may not be
significantly affected.
Pheochromocytoma: If Lopressor is used in the setting of pheochromocytoma, it should be given in combination with an alpha
blocker, and only after the alpha blocker has been initiated. Administration of beta blockers alone in the setting of pheochromocytoma
has been associated with a paradoxical increase in blood pressure due to the attenuation of beta-mediated vasodilatation in skeletal
muscle.
Thyrotoxicosis: Beta-adrenergic blockade may mask certain clinical signs (e.g., tachycardia) of hyperthyroidism. Patients suspected of
developing thyrotoxicosis should be managed carefully to avoid abrupt withdrawal of beta blockade, which might precipitate a thyroid
storm.
Myocardial Infarction
Cardiac Failure: Sympathetic stimulation is a vital component supporting circulatory function, and beta blockade carries the potential
hazard of depressing myocardial contractility and precipitating or exacerbating minimal cardiac failure.
During treatment with Lopressor, the hemodynamic status of the patient should be carefully monitored. If heart failure occurs or
persists despite appropriate treatment, Lopressor should be discontinued.
Bradycardia: Lopressor produces a decrease in sinus heart rate in most patients; this decrease is greatest among patients with high
initial heart rates and least among patients with low initial heart rates. Acute myocardial infarction (particularly inferior infarction)
may in itself produce significant lowering of the sinus rate. If the sinus rate decreases to <40 beats/min, particularly if associated
with evidence of lowered cardiac output, atropine (0.25-0.5 mg) should be administered intravenously. If treatment with atropine is
not successful, Lopressor should be discontinued, and cautious administration of isoproterenol or installation of a cardiac pacemaker
should be considered.
AV Block: Lopressor slows AV conduction and may produce significant first- (P-R interval ≥0.26 sec), second-, or third-degree heart
block. Acute myocardial infarction also produces heart block.
If heart block occurs, Lopressor should be discontinued and atropine (0.25-0.5 mg) should be administered intravenously. If treatment
with atropine is not successful, cautious administration of isoproterenol or installation of a cardiac pacemaker should be considered.
Hypotension: If hypotension (systolic blood pressure ≤90 mmHg) occurs, Lopressor should be discontinued, and the hemodynamic
status of the patient and the extent of myocardial damage carefully assessed. Invasive monitoring of central venous, pulmonary
capillary wedge, and arterial pressures may be required. Appropriate therapy with fluids, positive inotropic agents, balloon
counterpulsation, or other treatment modalities should be instituted. If hypotension is associated with sinus bradycardia or AV block,
treatment should be directed at reversing these (see above).
Bronchospastic Diseases: PATIENTS WITH BRONCHOSPASTIC DISEASES SHOULD, IN GENERAL, NOT RECEIVE
BETA BLOCKERS, including Lopressor. Because of its relative beta1 selectivity, Lopressor may be used with extreme
caution in patients with bronchospastic disease. Because it is unknown to what extent beta2-stimulating agents may exacerbate
myocardial ischemia and the extent of infarction, these agents should not be used prophylactically. If bronchospasm not
related to congestive heart failure occurs, Lopressor should be discontinued. A theophylline derivative or a beta2 agonist may
be administered cautiously, depending on the clinical condition of the patient. Both theophylline derivatives and beta2 agonists
may produce serious cardiac arrhythmias.
PRECAUTIONS
General
Lopressor should be used with caution in patients with impaired hepatic function.
Information for Patients
Patients should be advised to take Lopressor regularly and continuously, as directed, with or immediately following meals. If a
dose should be missed, the patient should take only the next scheduled dose (without doubling it). Patients should not discontinue
Lopressor without consulting the physician.
Patients should be advised (1) to avoid operating automobiles and machinery or engaging in other tasks requiring alertness until the
patient’s response to therapy with Lopressor has been determined; (2) to contact the physician if any difficulty in breathing occurs; (3)
to inform the physician or dentist before any type of surgery that he or she is taking Lopressor.
Drug Interactions
Catecholamine-depleting drugs (e.g., reserpine) may have an additive effect when given with beta-blocking agents. Patients
treated with Lopressor plus a catecholamine depletor should therefore be closely observed for evidence of hypotension or marked
bradycardia, which may produce vertigo, syncope, or postural hypotension.
Both digitalis glycosides and beta blockers slow atrioventricular conduction and decrease heart rate. Concomitant use can increase the
risk of bradycardia.
Risk of Anaphylactic Reaction: While taking beta blockers, patients with a history of severe anaphylactic reaction to a variety of
allergens may be more reactive to repeated challenge, either accidental, diagnostic, or therapeutic. Such patients may be unresponsive
to the usual doses of epinephrine used to treat allergic reaction.
General Anesthetics
Some inhalation anesthetics may enhance the cardiodepressant effect of beta blockers (see WARNINGS, Major Surgery).
CYP2D6 Inhibitors
Potent inhibitors of the CYP2D6 enzyme may increase the plasma concentration of Lopressor. Strong inhibition of CYP2D6 would
mimic the pharmacokinetics of CYP2D6 poor metabolizer (see Pharmacokinetics section). Caution should therefore be exercised
when coadministering potent CYP2D6 inhibitors with Lopressor. Known clinically significant potent inhibitors of CYP2D6 are
antidepressants such as fluoxetine, paroxetine or bupropion, antipsychotics such as thioridazine, antiarrhythmics such as quinidine or
propafenone, antiretrovirals such as ritonavir, antihistamines such as diphenhydramine, antimalarials such as hydroxychloroquine or
quinidine, antifungals such as terbinafine and medications for stomach ulcers such as cimetidine.
Clonidine
If a patient is treated with clonidine and Lopressor concurrently, and clonidine treatment is to be discontinued, Lopressor should be
stopped several days before clonidine is withdrawn. Rebound hypertension that can follow withdrawal of clonidine may be increased
in patients receiving concurrent beta-blocker treatment.
Carcinogenesis, Mutagenesis, Impairment of Fertility
Long-term studies in animals have been conducted to evaluate carcinogenic potential. In a 2-year study in rats at three oral dosage
levels of up to 800 mg/kg per day, there was no increase in the development of spontaneously occurring benign or malignant
neoplasms of any type. The only histologic changes that appeared to be drug related were an increased incidence of generally mild
focal accumulation of foamy macrophages in pulmonary alveoli and a slight increase in biliary hyperplasia. In a 21-month study
in Swiss albino mice at three oral dosage levels of up to 750 mg/kg per day, benign lung tumors (small adenomas) occurred more
frequently in female mice receiving the highest dose than in untreated control animals. There was no increase in malignant or total
(benign plus malignant) lung tumors, or in the overall incidence of tumors or malignant tumors. This 21-month study was repeated in
CD-1 mice, and no statistically or biologically significant differences were observed between treated and control mice of either sex for
any type of tumor.
All mutagenicity tests performed (a dominant lethal study in mice, chromosome studies in somatic cells, a Salmonella/mammalian-
microsome mutagenicity test, and a nucleus anomaly test in somatic interphase nuclei) were negative.
No evidence of impaired fertility due to Lopressor was observed in a study performed in rats at doses up to 55.5 times the maximum
daily human dose of 450 mg.
Pregnancy Category C
Lopressor has been shown to increase postimplantation loss and decrease neonatal survival in rats at doses up to 55.5 times the
maximum daily human dose of 450 mg. Distribution studies in mice confirm exposure of the fetus when Lopressor is administered to
the pregnant animal. These studies have revealed no evidence of impaired fertility or teratogenicity. There are no adequate and well-
controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug
should be used during pregnancy only if clearly needed.
Nursing Mothers
Lopressor is excreted in breast milk in a very small quantity. An infant consuming 1 liter of breast milk daily would receive a dose of
less than 1 mg of the drug. Caution should be exercised when Lopressor is administered to a nursing woman.
Pediatric Use
Safety and effectiveness in pediatric patients have not been established.
Geriatric Use
Clinical trials of Lopressor in hypertension did not include sufficient numbers of elderly patients to determine whether patients over
65 years of age differ from younger subjects in their response to Lopressor. Other reported clinical experience in elderly hypertensive
patients has not identified any difference in response from younger patients.
In worldwide clinical trials of Lopressor in myocardial infarction, where approximately 478 patients were over 65 years of age (0 over
75 years of age), no age-related differences in safety and effectiveness were found. Other reported clinical experience in myocardial
infarction has not identified differences in response between the elderly and younger patients. However, greater sensitivity of someelderly individuals taking Lopressor cannot be categorically ruled out. Therefore, in general, it is recommended that dosing proceedwith caution in this population.
ADVERSE REACTIONS
Hypertension and Angina
Most adverse effects have been mild and transient.
Central Nervous System: Tiredness and dizziness have occurred in about 10 of 100 patients. Depression has been reported in about
5 of 100 patients. Mental confusion and short-term memory loss have been reported. Headache, nightmares, and insomnia have also
been reported.
Cardiovascular: Shortness of breath and bradycardia have occurred in approximately 3 of 100 patients. Cold extremities; arterial
insufficiency, usually of the Raynaud type; palpitations; congestive heart failure; peripheral edema; and hypotension have been
reported in about 1 of 100 patients. Gangrene in patients with pre-existing severe peripheral circulatory disorders has also been
reported very rarely. (See CONTRAINDICATIONS, WARNINGS, and PRECAUTIONS.)
Respiratory: Wheezing (bronchospasm) and dyspnea have been reported in about 1 of 100 patients (see WARNINGS). Rhinitis has
also been reported.
Gastrointestinal: Diarrhea has occurred in about 5 of 100 patients. Nausea, dry mouth, gastric pain, constipation, flatulence, and
heartburn have been reported in about 1 of 100 patients. Vomiting was a common occurrence. Postmarketing experience reveals very
rare reports of hepatitis, jaundice and non-specific hepatic dysfunction. Isolated cases of transaminase, alkaline phosphatase, and lactic
dehydrogenase elevations have also been reported.
Hypersensitive Reactions: Pruritus or rash have occurred in about 5 of 100 patients. Very rarely, photosensitivity and worsening of
psoriasis has been reported.
Miscellaneous: Peyronie’s disease has been reported in fewer than 1 of 100,000 patients. Musculoskeletal pain, blurred vision, and
tinnitus have also been reported.
There have been rare reports of reversible alopecia, agranulocytosis, and dry eyes. Discontinuation of the drug should be considered if
any such reaction is not otherwise explicable. There have been very rare reports of weight gain, arthritis, and retroperitoneal fibrosis
(relationship to Lopressor has not been definitely established).
The oculomucocutaneous syndrome associated with the beta blocker practolol has not been reported with Lopressor.
Myocardial Infarction
Central Nervous System: Tiredness has been reported in about 1 of 100 patients. Vertigo, sleep disturbances, hallucinations,
headache, dizziness, visual disturbances, confusion, and reduced libido have also been reported, but a drug relationship is not clear.
Cardiovascular: In the randomized comparison of Lopressor and placebo described in the CLINICAL PHARMACOLOGY section,
the following adverse reactions were reported:
Lopressor®
Bradycardia (heart rate <40 beats/min) First-degree heart block (P-R ≥0.26 sec) Respiratory: Dyspnea of pulmonary origin has been reported in fewer than 1 of 100 patients.
Gastrointestinal: Nausea and abdominal pain have been reported in fewer than 1 of 100 patients.
Dermatologic: Rash and worsened psoriasis have been reported, but a drug relationship is not clear.
Miscellaneous: Unstable diabetes and claudication have been reported, but a drug relationship is not clear.
Potential Adverse Reactions
A variety of adverse reactions not listed above have been reported with other beta-adrenergic blocking agents and should be
considered potential adverse reactions to Lopressor.
Central Nervous System: Reversible mental depression progressing to catatonia; an acute reversible syndrome characterized by
disorientation for time and place, short-term memory loss, emotional lability, slightly clouded sensorium, and decreased performance
on neuropsychometrics.
Cardiovascular: Intensification of AV block (see CONTRAINDICATIONS).
Hematologic: Agranulocytosis, nonthrombocytopenic purpura, thrombocytopenic purpura.
Hypersensitive Reactions: Fever combined with aching and sore throat, laryngospasm, and respiratory distress.
Postmarketing Experience
The following adverse reactions have been reported during postapproval use of Lopressor: confusional state, an increase in blood
triglycerides and a decrease in High Density Lipoprotein (HDL). Because these reports are from a population of uncertain size and are
subject to confounding factors, it is not possible to reliably estimate their frequency.
OVERDOSAGE
Acute Toxicity
Several cases of overdosage have been reported, some leading to death.
Oral LD 50’s (mg/kg): mice, 1158-2460; rats, 3090-4670.
Signs and Symptoms
Potential signs and symptoms associated with overdosage with Lopressor are bradycardia, hypotension, bronchospasm, and cardiac
failure.
Treatment
There is no specific antidote.
In general, patients with acute or recent myocardial infarction may be more hemodynamically unstable than other patients and should
be treated accordingly (see WARNINGS, Myocardial Infarction).
On the basis of the pharmacologic actions of Lopressor, the following general measures should be employed:
Elimination of the Drug: Gastric lavage should be performed.
Bradycardia: Atropine should be administered. If there is no response to vagal blockade, isoproterenol should be administered
cautiously.
Hypotension: A vasopressor should be administered, e.g., levarterenol or dopamine.
Bronchospasm: A beta2-stimulating agent and/or a theophylline derivative should be administered.
Cardiac Failure: A digitalis glycoside and diuretic should be administered. In shock resulting from inadequate cardiac contractility,
administration of dobutamine, isoproterenol, or glucagon may be considered.
DOSAGE AND ADMINISTRATION
Hypertension
The dosage of Lopressor tablets should be individualized. Lopressor tablets should be taken with or immediately following meals.
The usual initial dosage of Lopressor tablets is 100 mg daily in single or divided doses, whether used alone or added to a diuretic.
The dosage may be increased at weekly (or longer) intervals until optimum blood pressure reduction is achieved. In general, the
maximum effect of any given dosage level will be apparent after 1 week of therapy. The effective dosage range of Lopressor tablets
is 100-450 mg per day. Dosages above 450 mg per day have not been studied. While once-daily dosing is effective and can maintain
a reduction in blood pressure throughout the day, lower doses (especially 100 mg) may not maintain a full effect at the end of the 24-
hour period, and larger or more frequent daily doses may be required. This can be evaluated by measuring blood pressure near the end
of the dosing interval to determine whether satisfactory control is being maintained throughout the day. Beta1 selectivity diminishes as
the dose of Lopressor is increased.
Angina Pectoris
The dosage of Lopressor tablets should be individualized. Lopressor tablets should be taken with or immediately following meals.
The usual initial dosage of Lopressor tablets is 100 mg daily, given in two divided doses. The dosage may be gradually increased at
weekly intervals until optimum clinical response has been obtained or there is pronounced slowing of the heart rate. The effective
dosage range of Lopressor tablets is 100-400 mg per day. Dosages above 400 mg per day have not been studied. If treatment is to be
discontinued, the dosage should be reduced gradually over a period of 1-2 weeks (see WARNINGS).
Myocardial Infarction
Early Treatment: During the early phase of definite or suspected acute myocardial infarction, treatment with Lopressor can be
initiated as soon as possible after the patient’s arrival in the hospital. Such treatment should be initiated in a coronary care or similar
unit immediately after the patient’s hemodynamic condition has stabilized.
Treatment in this early phase should begin with the intravenous administration of three bolus injections of 5 mg of Lopressor each; the
injections should be given at approximately 2-minute intervals. During the intravenous administration of Lopressor, blood pressure,
heart rate, and electrocardiogram should be carefully monitored.
In patients who tolerate the full intravenous dose (15 mg), Lopressor tablets, 50 mg every 6 hours, should be initiated 15 minutes after
the last intravenous dose and continued for 48 hours. Thereafter, patients should receive a maintenance dosage of 100 mg twice daily
(see Late Treatment below).
Patients who appear not to tolerate the full intravenous dose should be started on Lopressor tablets either 25 mg or 50 mg every
6 hours (depending on the degree of intolerance) 15 minutes after the last intravenous dose or as soon as their clinical condition
allows. In patients with severe intolerance, treatment with Lopressor should be discontinued (see WARNINGS).
Late Treatment: Patients with contraindications to treatment during the early phase of suspected or definite myocardial infarction,
patients who appear not to tolerate the full early treatment, and patients in whom the physician wishes to delay therapy for any other
reason should be started on Lopressor tablets, 100 mg twice daily, as soon as their clinical condition allows. Therapy should be
continued for at least 3 months. Although the efficacy of Lopressor beyond 3 months has not been conclusively established, data from
studies with other beta blockers suggest that treatment should be continued for 1-3 years.
Note: Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration,
whenever solution and container permit.
HOW SUPPLIED
Lopressor® Tablets
metoprolol tartrate tablets, USP
Tablets 50 mg – capsule-shaped, biconvex, pink, scored (imprinted GEIGY on one side and 51 twice on the scored side)
Bottles of 100………………………………………………………………NDC 0078-0458-05
Tablets 100 mg – capsule-shaped, biconvex, light blue, scored (imprinted GEIGY on one side and 71 twice on the scored side)
Bottles of 100………………………………………………………………NDC 0078-0459-05
Store at 25°C (77°F); excursions permitted to 15-30°C (59-86°F) [see USP Controlled Room Temperature]. Protect from moisture.
Dispense in tight, light-resistant container (USP).
Lopressor® Injection
metoprolol tartrate injection, USP
Ampuls 5 mL – each containing 5 mg of metoprolol tartrate
Carton of 10 ampuls……………………………………………………….NDC 0078-0400-01
Store at 25°C (77°F); excursions permitted to 15-30°C (59-86°F) [see USP Controlled Room Temperature]. Protect from light.
To report SUSPECTED ADVERSE REACTIONS, contact Novartis Pharmaceuticals Corporation at 1-888-669-6682 or FDA
at 1-800-FDA-1088 or www.fda.gov/medwatch
Tablets manufactured by:
Novartis Pharmaceuticals Corporation
Suffern, New York 10901
Ampuls manufactured by:
Novartis Pharma Stein AG
Stein, Switzerland
Distributed by:
Novartis Pharmaceuticals Corporation
East Hanover, New Jersey 07936
REV: JANUARY 2011
T2011-07
PRINCIPAL DISPLAY PANEL
Package Label – 50 mg
Rx Only NDC 0078-0458-05
Lopressor®
metoprolol tartrate USP
50 mg
100 Tablets
PRINCIPAL DISPLAY PANEL
Package Label – 100 mg
Rx Only NDC 0078-0459-05
Lopressor®
metoprolol tartrate USP
100 mg
100 Tablets
PRINCIPAL DISPLAY PANEL
Package Label – 5 mg per 5 mL
Rx Only NDC 0078-0400-61
Lopressor®
metoprolol tartrate injection, USP
5 mg per 5 mL
For Intravenous Use
(5 mL ampul)

Source: http://ns2.medconnections.com/drugs/pdf/lopressor.pdf