Label: BISOPROLOL FUMARATE AND HYDROCHLOROTHIAZIDE tablet, film coated

Bisoprolol Fumarate and Hydrochlorothiazide Tablets, USP are indicated for the treatment of hypertension. It combines two antihypertensive agents in a once-daily dosage: a synthetic beta1‑selective (cardioselective) adrenoceptor blocking agent (bisoprolol fumarate) and a benzothiadiazine diuretic (hydrochlorothiazide).

Bisoprolol fumarate, USP is chemically described as (±)-1-[4-[[2-(1‑methylethoxy)ethoxy]methyl]phenoxy]-3-[(1-methylethyl)amino]-2-propanol(E)-2-butenedioate (2:1) (salt). It possesses an asymmetric carbon atom in its structure and is provided as a racemic mixture. The S(-) enantiomer is responsible for most of the beta-blocking activity. Its empirical formula is (C18H31NO4)2•C4H4O4 and it has a molecular weight of 766.96 g/mol. Its structural formula is:

Bisoprolol fumarate, USP is a white crystalline powder, approximately equally hydrophilic and lipophilic, and very soluble in water, methanol, freely soluble in alcohol, glacial acetic acid and chloroform and slightly soluble in acetone and ethyl acetate.

Hydrochlorothiazide (HCTZ), USP is 6-Chloro-3,4-dihydro-2H-1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide. It is a white, or almost white, almost odorless crystalline powder. It is very slightly soluble in water, soluble in acetone, freely soluble in n-butylamine, N,N-dimethylformamide and diluted solutions of alkali hydroxides, sparingly soluble in methanol and ethanol, and practically insoluble in ether, chloroform, and dilute mineral acids. Its empirical formula is C7H8ClN3O4S2 and it has a molecular weight of 297.7 g/mol. Its structural formula is:

Each Bisoprolol Fumarate and Hydrochlorothiazide Tablet, USP 2.5 mg/6.25 mg for oral administration contains:

Bisoprolol fumarate, USP----------------------------------------------------------------2.5 mg

Hydrochlorothiazide, USP---------------------------------------------------------------6.25 mg

Each Bisoprolol Fumarate and Hydrochlorothiazide Tablet, USP 5 mg/6.25 mg for oral administration contains:

Bisoprolol fumarate, USP----------------------------------------------------------------5 mg

Hydrochlorothiazide, USP---------------------------------------------------------------6.25 mg

Each Bisoprolol Fumarate and Hydrochlorothiazide Tablet, USP 10 mg/6.25 mg for oral administration contains:

Bisoprolol fumarate, USP----------------------------------------------------------------10 mg

Hydrochlorothiazide, USP---------------------------------------------------------------6.25 mg

Inactive ingredients include Colloidal Silicon Dioxide, Corn Starch, Dibasic Calcium Phosphate Dihydrate, Hypromellose, Magnesium Stearate, Microcrystalline Cellulose, Polyethylene Glycol, Polysorbate 80, and Titanium Dioxide. The 5 mg/6.25 mg tablet also contains Red and Yellow Iron Oxide. The 2.5 mg/6.25 mg tablet also contains Yellow Iron Oxide.

Bisoprolol fumarate and HCTZ have been used individually and in combination for the treatment of hypertension. The antihypertensive effects of these agents are additive; HCTZ 6.25 mg significantly increases the antihypertensive effect of bisoprolol fumarate. The incidence of hypokalemia with the bisoprolol fumarate and HCTZ 6.25 mg combination (B/H) is significantly lower than with HCTZ 25 mg. In clinical trials of bisoprolol fumarate and hydrochlorothiazide tablets, mean changes in serum potassium for patients treated with bisoprolol fumarate and hydrochlorothiazide tablets 2.5/6.25 mg, 5/6.25 mg or 10/6.25 mg or placebo were less than ± 0.1 mEq/L. Mean changes in serum potassium for patients treated with any dose of bisoprolol in combination with HCTZ 25 mg ranged from -0.1 to -0.3 mEq/L.

Bisoprolol fumarate is a beta1-selective (cardioselective) adrenoceptor blocking agent without significant membrane stabilizing or intrinsic sympathomimetic activities in its therapeutic dose range. At higher doses (≥20 mg) bisoprolol fumarate also inhibits beta2-adrenoreceptors located in bronchial and vascular musculature. To retain relative selectivity, it is important to use the lowest effective dose.

Hydrochlorothiazide is a benzothiadiazine diuretic. Thiazides affect renal tubular mechanisms of electrolyte reabsorption and increase excretion of sodium and chloride in approximately equivalent amounts. Natriuresis causes a secondary loss of potassium.

Pharmacokinetics and Metabolism

Bisoprolol Fumarate and Hydrochlorothiazide Tablets

In healthy volunteers, both bisoprolol fumarate and hydrochlorothiazide are well absorbed following oral administration of bisoprolol fumarate and hydrochlorothiazide tablets. No change is observed in the bioavailability of either agent when given together in a single tablet. Absorption is not affected whether bisoprolol fumarate and hydrochlorothiazide tablets is taken with or without food. Mean peak bisoprolol fumarate plasma concentrations of about 9 ng/mL, 19 ng/mL and 36 ng/mL occur approximately 3 hours after the administration of the 2.5 mg/6.25 mg, 5 mg/6.25 mg and 10 mg/6.25 mg combination tablets, respectively. Mean peak plasma hydrochlorothiazide concentrations of 30 ng/mL occur approximately 2.5 hours following the administration of the combination. Dose proportional increases in plasma bisoprolol concentrations are observed between the 2.5 and 5, as well as between the 5 and 10 mg doses.

The elimination T1/2 of bisoprolol ranges from 7 to 15 hours, and that of hydrochlorothiazide ranges from 4 to 10 hours. The percent of dose excreted unchanged in urine is about 55% for bisoprolol and about 60% for hydrochlorothiazide.

Bisoprolol Fumarate

The absolute bioavailability after a 10 mg oral dose of bisoprolol fumarate is about 80%. The first pass metabolism of bisoprolol fumarate is about 20%.

The pharmacokinetic profile of bisoprolol fumarate has been examined following single doses and at steady state. Binding to serum proteins is approximately 30%. Peak plasma concentrations occur within 2 to 4 hours of dosing with 2.5 to 20 mg, and mean peak values range from 9 ng/mL at 2.5 mg to 70 ng/mL at 20 mg. Once-daily dosing with bisoprolol fumarate results in less than twofold intersubject variation in peak plasma concentrations. Plasma concentrations are proportional to the administered dose in the range of 2.5 to 20 mg. The plasma elimination half- life is 9 to 12 hours and is slightly longer in elderly patients, in part because of decreased renal function. Steady state is attained within 5 days with once-daily dosing. In both young and elderly populations, plasma accumulation is low; the accumulation factor ranges from 1.1 to 1.3 and is what would be expected from the half-life and once-daily dosing. Bisoprolol is eliminated equally by renal and nonrenal pathways with about 50% of the dose appearing unchanged in the urine and the remainder in the form of inactive metabolites. In humans, the known metabolites are labile or have no known pharmacologic activity. Less than 2% of the dose is excreted in the feces. The pharmacokinetic characteristics of the two enantiomers are similar. Bisoprolol is not metabolized by cytochrome P450 II D6 (debrisoquin hydroxylase).

In subjects with creatinine clearance less than 40 mL/min, the plasma half-life is increased approximately threefold compared to healthy subjects.

In patients with liver cirrhosis, the rate of elimination of bisoprolol is more variable and significantly slower than that in healthy subjects, with a plasma half-life ranging from 8 to 22 hours.

In elderly subjects, mean plasma concentrations at steady state are increased, in part attributed to lower creatinine clearance. However, no significant differences in the degree of bisoprolol accumulation is found between young and elderly populations.

Hydrochlorothiazide

Hydrochlorothiazide is well absorbed (65% to 75%) following oral administration. Absorption of hydrochlorothiazide is reduced in patients with congestive heart failure.

Peak plasma concentrations are observed within 1 to 5 hours of dosing and range from 70 to 490 ng/mL following oral doses of 12.5 to 100 mg. Plasma concentrations are linearly related to the administered dose. Concentrations of hydrochlorothiazide are 1.6 to 1.8 times higher in whole blood than in plasma. Binding to serum proteins has been reported to be approximately 40% to 68%. The plasma elimination half-life has been reported to be 6 to 15 hours. Hydrochlorothiazide is eliminated primarily by renal pathways. Following oral doses of 12.5 to 100 mg, 55% to 77% of the administered dose appears in urine and greater than 95% of the absorbed dose is excreted in urine as unchanged drug. Plasma concentrations of hydrochlorothiazide are increased, and the elimination half-life is prolonged in patients with renal disease.

Pharmacodynamics

Bisoprolol Fumarate

Findings in clinical hemodynamics studies with bisoprolol fumarate are similar to those observed with other beta-blockers. The most prominent effect is the negative chronotropic effect, giving a reduction in resting and exercise heart rate. There is a fall in resting and exercise cardiac output with little observed change in stroke volume, and only a small increase in right atrial pressure, or pulmonary capillary wedge pressure at rest or during exercise.

In normal volunteers, bisoprolol fumarate therapy resulted in a reduction of exercise- and isoproterenol-induced tachycardia. The maximal effect occurred within 1 to 4 hours post-dosing. Effects generally persisted for 24 hours at doses of 5 mg or greater.

In controlled clinical trials, bisoprolol fumarate given as a single daily dose has been shown to be an effective antihypertensive agent when used alone or concomitantly with thiazide diuretics (see CLINICAL STUDIES).

The mechanism of bisoprolol fumarate’s antihypertensive effect has not been completely established. Factors that may be involved include:

 

1. Decreased cardiac output,

 

2. Inhibition of renin release by the kidneys,

 

3. Diminution of tonic sympathetic outflow from vasomotor centers in the brain.

Beta1-selectivity of bisoprolol fumarate has been demonstrated in both animal and human studies. No effects at therapeutic doses on beta2-adrenoreceptor density have been observed. Pulmonary function studies have been conducted in healthy volunteers, asthmatics, and patients with chronic obstructive pulmonary disease (COPD). Doses of bisoprolol fumarate ranged from 5 to 60 mg, atenolol from 50 to 200 mg, metoprolol from 100 to 200 mg, and propranolol from 40 to 80 mg. In some studies, slight, asymptomatic increases in airway resistance (AWR) and decreases in forced expiratory volume (FEV1) were observed with doses of bisoprolol fumarate 20 mg and higher, similar to the small increases in AWR noted with other cardioselective beta- blocking agents. The changes induced by beta-blockade with all agents were reversed by bronchodilator therapy.

Electrophysiology studies in man have demonstrated that bisoprolol fumarate significantly decreases heart rate, increases sinus node recovery time, prolongs AV node refractory periods, and, with rapid atrial stimulation, prolongs AV nodal conduction.

Hydrochlorothiazide

Acute effects of thiazides are thought to result from a reduction in blood volume and cardiac output, secondary to a natriuretic effect, although a direct vasodilatory mechanism has also been proposed. With chronic administration, plasma volume returns toward normal, but peripheral vascular resistance is decreased.

Thiazides do not affect normal blood pressure. Onset of action occurs within 2 hours of dosing, peak effect is observed at about 4 hours, and activity persists for up to 24 hours.

In controlled clinical trials, bisoprolol fumarate/hydrochlorothiazide 6.25 mg has been shown to reduce systolic and diastolic blood pressure throughout a 24-hour period when administered once daily. The effects on systolic and diastolic blood pressure reduction of the combination of bisoprolol fumarate and hydrochlorothiazide were additive. Further, treatment effects were consistent across age groups (<60, ≥ 60 years), racial groups (black, nonblack), and gender (male, female).

In two randomized, double-blind, placebo-controlled trials conducted in the U.S., reductions in systolic and diastolic blood pressure and heart rate 24 hours after dosing in patients with mild-to‑moderate hypertension are shown below. In both studies mean systolic/diastolic blood pressure and heart rate at baseline were approximately 151/101 mm Hg and 77 bpm.

 

a Observed mean change from baseline minus placebo.

Blood pressure responses were seen within 1 week of treatment but the maximum effect was apparent after 2 to 3 weeks of treatment. Overall, significantly greater blood pressure reductions were observed on bisoprolol fumarate and hydrochlorothiazide tablets than on placebo. Further, blood pressure reductions were significantly greater for each of the bisoprolol fumarate plus hydrochlorothiazide combinations than for either of the components used alone regardless of race, age, or gender. There were no significant differences in response between black and nonblack patients.

Bisoprolol fumarate and hydrochlorothiazide tablets are indicated in the management of hypertension.

Bisoprolol fumarate and hydrochlorothiazide tablets are contraindicated in patients in cardiogenic shock, overt cardiac failure (see WARNINGS), second or third degree AV block, marked sinus bradycardia, anuria, and hypersensitivity to either component of this product or to other sulfonamide-derived drugs.

Cardiac Failure

In general, beta-blocking agents should be avoided in patients with overt congestive failure. However, in some patients with compensated cardiac failure, it may be necessary to utilize these agents. In such situations, they must be used cautiously.

Patients Without a History of Cardiac Failure

Continued depression of the myocardium with beta-blockers can, in some patients, precipitate cardiac failure. At the first signs or symptoms of heart failure, discontinuation of bisoprolol fumarate and hydrochlorothiazide tablets should be considered. In some cases bisoprolol fumarate and hydrochlorothiazide tablets therapy can be continued while heart failure is treated with other drugs.

Abrupt Cessation of Therapy

Exacerbations of angina pectoris and, in some instances, myocardial infarction or ventricular arrhythmia, have been observed in patients with coronary artery disease following abrupt cessation of therapy with beta-blockers. Such patients should, therefore, be cautioned against interruption or discontinuation of therapy without the physician’s advice. Even in patients without overt coronary artery disease, it may be advisable to taper therapy with bisoprolol fumarate and hydrochlorothiazide tablets over approximately 1 week with the patient under careful observation. If withdrawal symptoms occur, beta-blocking agent therapy should be reinstituted, at least temporarily.

Peripheral Vascular Disease

Beta-blockers can precipitate or aggravate symptoms of arterial insufficiency in patients with peripheral vascular disease. Caution should be exercised in such individuals.

Bronchospastic Disease

PATIENTS WITH BRONCHOSPASTIC PULMONARY DISEASE SHOULD, IN GENERAL, NOT RECEIVE BETA-BLOCKERS. Because of the relative beta1-selectivity of bisoprolol fumarate, bisoprolol fumarate and hydrochlorothiazide tablets may be used with caution in patients with bronchospastic disease who do not respond to, or who cannot tolerate other antihypertensive treatment.

Since beta1-selectivity is not absolute, the lowest possible dose of bisoprolol fumarate and hydrochlorothiazide tablets should be used. A beta2 agonist (bronchodilator) should be made available.

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.

Hypoglycemia

Beta-blockers may prevent early warning signs of hypoglycemia, such as tachycardia, and increase the risk for severe or prolonged hypoglycemia at any time during treatment, especially in patients with diabetes mellitus or children and patients who are fasting (i.e., surgery, not eating regularly, or are vomiting). If severe hypoglycemia occurs, patients should be instructed to seek emergency treatment. Also, latent diabetes mellitus may become manifest and diabetic patients given thiazides may require adjustment of their insulin dose.

Thyrotoxicosis

Beta-adrenergic blockade may mask clinical signs of hyperthyroidism, such as tachycardia. Abrupt withdrawal of beta-blockade may be followed by an exacerbation of the symptoms of hyperthyroidism or may precipitate thyroid storm.

Renal Disease

Cumulative effects of the thiazides may develop in patients with impaired renal function. In such patients, thiazides may precipitate azotemia. In subjects with creatinine clearance less than 40 mL/min, the plasma half-life of bisoprolol fumarate is increased up to threefold, as compared to healthy subjects. If progressive renal impairment becomes apparent, bisoprolol fumarate and hydrochlorothiazide tablets should be discontinued (see Pharmacokinetics and Metabolism).

Hepatic Disease

Bisoprolol fumarate and hydrochlorothiazide tablets should be used with caution in patients with impaired hepatic function or progressive liver disease. Thiazides may alter fluid and electrolyte balance, which may precipitate hepatic coma. Also, elimination of bisoprolol fumarate is significantly slower in patients with cirrhosis than in healthy subjects (see Pharmacokinetics and Metabolism).

Acute Angle-Closure Glaucoma with or without Acute Myopia and Choroidal Effusions

Hydrochlorothiazide, a sulfonamide, can cause an idiosyncratic reaction, resulting in acute angle-closure glaucoma and elevated intraocular pressure with or without a noticeable acute myopic shift and/or choroidal effusions. Symptoms may include acute onset of decreased visual acuity or ocular pain and typically occur within hours to weeks of drug initiation. Untreated, the acute angle-closure glaucoma may result in permanent visual field loss. The primary treatment is to discontinue hydrochlorothiazide as rapidly as possible. Prompt medical or surgical treatments may need to be considered if the intraocular pressure remains uncontrolled. Risk factors for developing acute angle-closure glaucoma may include a history of sulfonamide or penicillin allergy.

Bisoprolol Fumarate and Hydrochlorothiazide Tablets

Bisoprolol fumarate/HCTZ 6.25 mg is well tolerated in most patients. Most adverse effects (AEs) have been mild and transient. In more than 65,000 patients treated worldwide with bisoprolol fumarate, occurrences of bronchospasm have been rare. Discontinuation rates for AEs were similar for bisoprolol fumarate/HCTZ 6.25 mg and placebo-treated patients.

In the United States, 252 patients received bisoprolol fumarate (2.5, 5, 10, or 40 mg)/HCTZ 6.25 mg and 144 patients received placebo in two controlled trials. In Study 1, bisoprolol fumarate 5/HCTZ 6.25 mg was administered for 4 weeks. In Study 2, bisoprolol fumarate 2.5, 10, or 40/HCTZ 6.25 mg was administered for 12 weeks. All adverse experiences, whether drug related or not, and drug related adverse experiences in patients treated with bisoprolol fumarate 2.5‑10/HCTZ 6.25 mg, reported during comparable, 4-week treatment periods by at least 2% of bisoprolol fumarate/HCTZ 6.25 mg-treated patients (plus additional selected adverse experiences) are presented in the following table:

 

a Averages adjusted to combine across studies.

 

b Combined across studies.

Other adverse experiences that have been reported with the individual components are listed below.

Bisoprolol Fumarate

In clinical trials worldwide, or in postmarketing experience, a variety of other AEs, in addition to those listed above, have been reported. While in many cases it is not known whether a causal relationship exists between bisoprolol and these AEs, they are listed to alert the physician to a possible relationship.

Central Nervous System

Unsteadiness, dizziness, vertigo, headache, syncope, paresthesia, hypoesthesia, hyperesthesia, sleep disturbance/vivid dreams, insomnia, somnolence, depression, anxiety/restlessness, decreased concentration/memory.

Cardiovascular

Bradycardia, palpitations and other rhythm disturbances, cold extremities, claudication, hypotension, orthostatic hypotension, chest pain, congestive heart failure, dyspnea on exertion.

Gastrointestinal

Gastric/epigastric/abdominal pain, peptic ulcer, gastritis, dyspepsia, nausea, vomiting, diarrhea, constipation, dry mouth.

Musculoskeletal

Arthralgia, muscle/joint pain, back/neck pain, muscle cramps, twitching/tremor.

Skin

Rash, acne, eczema, psoriasis, skin irritation, pruritus, purpura, flushing, sweating, alopecia, dermatitis, exfoliative dermatitis (very rarely), cutaneous vasculitis.

Special Senses

Visual disturbances, ocular pain/pressure, abnormal lacrimation, tinnitus, decreased hearing, earache, taste abnormalities.

Metabolic

Gout.

Respiratory

Asthma, bronchospasm, bronchitis, dyspnea, pharyngitis, rhinitis, sinusitis, URI (upper respiratory infection).

Genitourinary

Decreased libido/impotence, Peyronie’s disease (very rarely), cystitis, renal colic, polyuria.

General

Fatigue, asthenia, chest pain, malaise, edema, weight gain, angioedema.

In addition, a variety of adverse effects have been reported with other beta-adrenergic blocking agents and should be considered potential adverse effects:

Central Nervous System

Reversible mental depression progressing to catatonia, hallucinations, an acute reversible syndrome characterized by disorientation to time and place, emotional lability, slightly clouded sensorium.

Allergic

Fever, combined with aching and sore throat, laryngospasm, and respiratory distress.

Hematologic

Agranulocytosis, thrombocytopenia.

Gastrointestinal

Mesenteric arterial thrombosis and ischemic colitis.

Miscellaneous

The oculomucocutaneous syndrome associated with the beta-blocker practolol has not been reported with bisoprolol fumarate during investigational use or extensive foreign marketing experience.

Hydrochlorothiazide

The following adverse experiences, in addition to those listed in the above table, have been reported with hydrochlorothiazide (generally with doses of 25 mg or greater).

General

Weakness.

Central Nervous System

Vertigo, paresthesia, restlessness.

Cardiovascular

Orthostatic hypotension (may be potentiated by alcohol, barbiturates, or narcotics).

Gastrointestinal

Anorexia, gastric irritation, cramping, constipation, jaundice (intrahepatic cholestatic jaundice), pancreatitis, cholecystitis, sialadenitis, dry mouth.

Musculoskeletal

Muscle spasm.

Hypersensitive Reactions

Purpura, photosensitivity, rash, urticaria, necrotizing angiitis (vasculitis and cutaneous vasculitis), fever, respiratory distress including pneumonitis and pulmonary edema, anaphylactic reactions.

Special Senses

Transient blurred vision, choroidal effusion, xanthopsia.

Metabolic

Gout.

Genitourinary

Sexual dysfunction, renal failure, renal dysfunction, interstitial nephritis.

Skin

Erythema multiforme including Stevens-Johnson syndrome, exfoliative dermatitis including toxic epidermal necrolysis.

Postmarketing Experience Non-melanoma Skin Cancer

Hydrochlorothiazide is associated with an increased risk of non-melanoma skin cancer. In a study conducted in the Sentinel System, increased risk was predominantly for squamous cell carcinoma (SCC) and in white patients taking large cumulative doses. The increased risk for SCC in the overall population was approximately 1 additional case per 16,000 patients per year, and for white patients taking a cumulative dose of ≥50,000 mg the risk increase was approximately 1 additional SCC case for every 6,700 patients per year.

Laboratory Abnormalities

Bisoprolol Fumarate and Hydrochlorothiazide Tablets

Because of the low dose of hydrochlorothiazide in bisoprolol fumarate and hydrochlorothiazide tablets, adverse metabolic effects with bisoprolol fumarate/HCTZ 6.25 mg are less frequent and of smaller magnitude than with HCTZ 25 mg. Laboratory data on serum potassium from the U.S. placebo-controlled trials are shown in the following table:

a Combined across studies.

b Patients with normal serum potassium at baseline.

c Mean change from baseline at Week 4.

d Percentage of patients with abnormality at Week 4.

Treatment with both beta blockers and thiazide diuretics is associated with increases in uric acid. However, the magnitude of the change in patients treated with B/H 6.25 mg was smaller than in patients treated with HCTZ 25 mg. Mean increases in serum triglycerides were observed in patients treated with bisoprolol fumarate and hydrochlorothiazide 6.25 mg. Total cholesterol was generally unaffected, but small decreases in HDL cholesterol were noted.

Other laboratory abnormalities that have been reported with the individual components are listed below.

Bisoprolol Fumarate

In clinical trials, the most frequently reported laboratory change was an increase in serum triglycerides, but this was not a consistent finding.

Sporadic liver test abnormalities have been reported. In the U.S. controlled trials experience with bisoprolol fumarate treatment for 4 to 12 weeks, the incidence of concomitant elevations in SGOT and SGPT from 1 to 2 times normal was 3.9%, compared to 2.5% for placebo. No patient had concomitant elevations greater than twice normal.

In the long-term, uncontrolled experience with bisoprolol fumarate treatment for 6 to 18 months, the incidence of one or more concomitant elevations in SGOT and SGPT from 1 to 2 times normal was 6.2%. The incidence of multiple occurrences was 1.9%. For concomitant elevations in SGOT and SGPT of greater than twice normal, the incidence was 1.5%. The incidence of multiple occurrences was 0.3%. In many cases these elevations were attributed to underlying disorders, or resolved during continued treatment with bisoprolol fumarate.

Other laboratory changes included small increases in uric acid, creatinine, BUN, serum potassium, glucose, and phosphorus and decreases in WBC and platelets. There have been occasional reports of eosinophilia. These were generally not of clinical importance and rarely resulted in discontinuation of bisoprolol fumarate.

As with other beta-blockers, ANA conversions have also been reported on bisoprolol fumarate. About 15% of patients in long-term studies converted to a positive titer, although about one-third of these patients subsequently reconverted to a negative titer while on continued therapy.

Hydrochlorothiazide

Hyperglycemia, glycosuria, hyperuricemia, hypokalemia and other electrolyte imbalances (see PRECAUTIONS), hyperlipidemia, hypercalcemia, leukopenia, agranulocytosis, thrombocytopenia, aplastic anemia, and hemolytic anemia have been associated with HCTZ therapy.

There are limited data on overdose with bisoprolol fumarate and hydrochlorothiazide tablets. However, several cases of overdose with bisoprolol fumarate have been reported (maximum: 2000 mg). Bradycardia and/or hypotension were noted. Sympathomimetic agents were given in some cases, and all patients recovered.

The most frequently observed signs expected with overdosage of a beta-blocker are bradycardia and hypotension. Lethargy is also common, and with severe overdoses, delirium, coma, convulsions, and respiratory arrest have been reported to occur. Congestive heart failure, bronchospasm, and hypoglycemia may occur, particularly in patients with underlying conditions. With thiazide diuretics, acute intoxication is rare. The most prominent feature of overdose is acute loss of fluid and electrolytes. Signs and symptoms include cardiovascular (tachycardia, hypotension, shock), neuromuscular (weakness, confusion, dizziness, cramps of the calf muscles, paresthesia, fatigue, impairment of consciousness), gastrointestinal (nausea, vomiting, thirst), renal (polyuria, oliguria, or anuria [due to hemoconcentration]), and laboratory findings (hypokalemia, hyponatremia, hypochloremia, alkalosis, increased BUN [especially in patients with renal insufficiency]).

If overdosage of bisoprolol fumarate and hydrochlorothiazide tablets is suspected, therapy with bisoprolol fumarate and hydrochlorothiazide tablets should be discontinued and the patient observed closely. Treatment is symptomatic and supportive; there is no specific antidote. Limited data suggest bisoprolol fumarate is not dialyzable; similarly, there is no indication that hydrochlorothiazide is dialyzable. Suggested general measures include induction of emesis and/or gastric lavage, administration of activated charcoal, respiratory support, correction of fluid and electrolyte imbalance, and treatment of convulsions. Based on the expected pharmacologic actions and recommendations for other beta- blockers and hydrochlorothiazide, the following measures should be considered when clinically warranted:

Bradycardia

Administer IV atropine. If the response is inadequate, isoproterenol or another agent with positive chronotropic properties may be given cautiously. Under some circumstances, transvenous pacemaker insertion may be necessary.

Hypotension, Shock

The patient’s legs should be elevated. IV fluids should be administered and lost electrolytes (potassium, sodium) replaced. Intravenous glucagon may be useful. Vasopressors should be considered.

Heart Block (second or third degree)

Patients should be carefully monitored and treated with isoproterenol infusion or transvenous cardiac pacemaker insertion, as appropriate.

Congestive Heart Failure

Initiate conventional therapy (ie, digitalis, diuretics, vasodilating agents, inotropic agents).

Bronchospasm

Administer a bronchodilator such as isoproterenol and/or aminophylline.

Hypoglycemia

Administer IV glucose.

Surveillance

Fluid and electrolyte balance (especially serum potassium) and renal function should be monitored until normalized.

Bisoprolol is an effective treatment of hypertension in once-daily doses of 2.5 to 40 mg, while hydrochlorothiazide is effective in doses of 12.5 to 50 mg. In clinical trials of bisoprolol/hydrochlorothiazide combination therapy using bisoprolol doses of 2.5 to 20 mg and hydrochlorothiazide doses of 6.25 to 25 mg, the antihypertensive effects increased with increasing doses of either component.

The adverse effects (see WARNINGS) of bisoprolol are a mixture of dose-dependent phenomena (primarily bradycardia, diarrhea, asthenia, and fatigue) and dose-independent phenomena (eg, occasional rash); those of hydrochlorothiazide are a mixture of dose-dependent phenomena (primarily hypokalemia) and dose-independent phenomena (eg, possibly pancreatitis); the dose- dependent phenomena for each being much more common than the dose-independent phenomena. The latter consist of those few that are truly idiosyncratic in nature or those that occur with such low frequency that a dose relationship may be difficult to discern. Therapy with a combination of bisoprolol and hydrochlorothiazide will be associated with both sets of dose- independent adverse effects, and to minimize these, it may be appropriate to begin combination therapy only after a patient has failed to achieve the desired effect with monotherapy. On the other hand, regimens that combine low doses of bisoprolol and hydrochlorothiazide should produce minimal dose-dependent adverse effects, eg, bradycardia, diarrhea, asthenia and fatigue, and minimal dose-dependent adverse metabolic effects, ie, decreases in serum potassium (see CLINICAL PHARMACOLOGY).

Therapy Guided by Clinical Effect

A patient whose blood pressure is not adequately controlled with 2.5 to 20 mg bisoprolol daily may instead be given bisoprolol fumarate and hydrochlorothiazide tablets. Patients whose blood pressures are adequately controlled with 50 mg of hydrochlorothiazide daily, but who experience significant potassium loss with this regimen, may achieve similar blood pressure control without electrolyte disturbance if they are switched to bisoprolol fumarate and hydrochlorothiazide tablets.

Initial Therapy

Antihypertensive therapy may be initiated with the lowest dose of bisoprolol fumarate and hydrochlorothiazide tablets, one 2.5/6.25 mg tablet once daily. Subsequent titration (14-day intervals) may be carried out with bisoprolol fumarate and hydrochlorothiazide tablets up to the maximum recommended dose 20/12.5 mg (two 10/6.25 mg tablets) once daily, as appropriate.

Replacement Therapy

The combination may be substituted for the titrated individual components.

Cessation of Therapy

If withdrawal of bisoprolol fumarate and hydrochlorothiazide tablets therapy is planned, it should be achieved gradually over a period of about 2 weeks. Patients should be carefully observed.

Patients with Renal or Hepatic Impairment: As noted in the WARNINGS section, caution must be used in dosing/titrating patients with hepatic impairment or renal dysfunction. Since there is no indication that hydrochlorothiazide is dialyzable, and limited data suggest that bisoprolol is not dialyzable, drug replacement is not necessary in patients undergoing dialysis.

Geriatric Patients: Dosage adjustment on the basis of age is not usually necessary, unless there is also significant renal or hepatic dysfunction (see above and WARNINGS section).

Pediatric Patients: There is no pediatric experience with bisoprolol fumarate and hydrochlorothiazide tablets.

Product: 50090-7357

NDC: 50090-7357-0 30 TABLET, FILM COATED in a BOTTLE

NDC: 50090-7357-2 90 TABLET, FILM COATED in a BOTTLE