DRUGS & SUPPLEMENTS

Isobar

Rating: 5 - 1 review(s)
advertisement
How long you have been taking the medicine?

Isobar uses

Isobar consists of Methyclothiazide, Triamterene.

Methyclothiazide:


DESCRIPTION

Isobar (Methyclothiazide), a diuretic-antihypertensive agent, is a member of the benzothiadiazine (thiazide) class of drugs. It is an analogue of hydrochlorothiazide and occurs as a white to practically white crystalline powder which is basically odorless. Isobar (Methyclothiazide) is very slightly soluble in water and chloroform, and slightly soluble in alcohol. Chemically, Isobar (Methyclothiazide) is represented as 6-chloro-3-(chloromethyl)-3,4-dihydro-2-methyl-2H-1,2,4-benzothiadiazine-7-sulfonamide 1,1-dioxide. The structural formula is:

Each Isobar (Methyclothiazide) tablet, USP for oral administration contains 5 mg Isobar (Methyclothiazide), USP and the following inactive ingredients: colloidal silicon dioxide, FD&C Blue No. 1 Aluminum Lake, magnesium stearate, microcrystalline cellulose, pregelatinized starch, sodium lauryl sulfate and sodium starch glycolate.

Structural Formula

CLINICAL PHARMACOLOGY

The diuretic and saluretic effects of Isobar (Methyclothiazide) result from a drug-induced inhibition of renal tubular reabsorption of electrolytes. The excretion of sodium and chloride is greatly enhanced. Potassium excretion is also enhanced to a variable degree, as it is with the other thiazides. Although urinary excretion of bicarbonate is increased slightly, there is usually no significant change in urinary pH. Isobar (Methyclothiazide) has a per mg natriuretic activity approximately 100 times that of the prototype thiazide, chlorothiazide. At maximal therapeutic dosages, all thiazides are approximately equal in their diuretic/natriuretic effects.

There is significant natriuresis and diuresis within 2 hours after administration of a single-dose of Isobar (Methyclothiazide). These effects reach a peak in about 6 hours and persist for 24 hours following oral administration of a single-dose.

Like other benzothiadiazines, Isobar (Methyclothiazide) also has antihypertensive properties, and may be used for this purpose either alone or to enhance the antihypertensive action of other drugs. The mechanism by which the benzothiadiazines, including Isobar (Methyclothiazide), produce a reduction of elevated blood pressure is not known. However, sodium depletion appears to be involved.

Isobar (Methyclothiazide) is rapidly absorbed and slowly eliminated by the kidneys as intact drug but primarily as an inactive metabolite. Additional information on the pharmacokinetics is not known at this time.

advertisement

INDICATIONS AND USAGE

Isobar tablets are indicated in the management of hypertension either as the sole therapeutic agent or to enhance the effect of other antihypertensive drugs in the more severe forms of hypertension.

Isobar (Methyclothiazide) tablets are indicated as adjunctive therapy in edema associated with congestive heart failure, hepatic cirrhosis, and corticosteroid and estrogen therapy.

Isobar (Methyclothiazide) tablets have also been found useful in edema due to various forms of renal dysfunction such as the nephrotic syndrome, acute glomerulonephritis, and chronic renal failure.

Usage in Pregnancy

The routine use of diuretics in an otherwise healthy pregnant woman is inappropriate and exposes mother and fetus to unnecessary hazard. Diuretics do not prevent development of toxemia of pregnancy, and there is no satisfactory evidence that they are useful in the treatment of developed toxemia.

Edema during pregnancy may arise from pathological causes or from the physiological and mechanical consequences of pregnancy. Thiazides are indicated in pregnancy when edema is due to pathological causes, just as they are in the absence of pregnancy. Dependent edema in pregnancy, resulting from restriction of venous return by the expanded uterus, is properly treated through elevation of the lower extremities and use of support hose; use of diuretics to lower intravascular volume in this case is illogical and unnecessary. There is hypervolemia during normal pregnancy that is harmful to neither the fetus nor the mother (in the absence of cardiovascular disease), but that is associated with edema, including generalized edema, in the majority of pregnant women. If this edema produces discomfort, increased recumbency will often provide relief. In rare instances, this edema may cause extreme discomfort that is not relieved by rest. In these cases, a short course of diuretics may provide relief and may be appropriate.

advertisement

CONTRAINDICATIONS

Isobar (Methyclothiazide) tablets are contraindicated in patients with anuria and in patients with a history of hypersensitivity to this compound or other sulfonamide-derived drugs.

WARNINGS

Isobar (Methyclothiazide) shares with other thiazides the propensity to deplete potassium reserves to an unpredictable degree.

There have been isolated reports that certain non-edematous individuals developed severe fluid and electrolyte derangements after only brief exposure to normal doses of thiazide and non-thiazide diuretics.

Thiazides should be used with caution in patients with renal disease or significant impairment of renal function, since azotemia may be precipitated and cumulative drug effects may occur.

Thiazides should be used with caution in patients with impaired hepatic function or progressive liver disease, since minor alterations of fluid and electrolyte balance may precipitate hepatic coma.

Sensitivity reactions may occur in patients with a history of allergy or bronchial asthma.

The possibility of exacerbation or activation of systemic lupus erythematosus has been reported.

Hyperuricemia may occur or frank gout may be precipitated in certain patients receiving thiazide therapy.

PRECAUTIONS

General

All patients should be observed for clinical signs of electrolyte imbalances such as dryness of mouth, thirst, weakness, lethargy, drowsiness, restlessness, muscle pains or cramps, muscular fatigue, hypotension, oliguria, tachycardia, and gastrointestinal disturbances such as nausea and vomiting.

Hypokalemia may develop, especially with brisk diuresis, when severe cirrhosis is present, during concomitant use of corticosteroids or ACTH, or after prolonged therapy.

Interference with adequate oral electrolyte intake will also contribute to hypokalemia. Hypokalemia may be avoided or treated by use of potassium supplements or foods with a high potassium content.

Any chloride deficit is generally mild and usually does not require specific treatment except under extraordinary circumstances. Dilutional hyponatremia may occur in edematous patients in hot weather; appropriate therapy is water restriction rather than administration of salt, except in rare instances when the hyponatremia is life threatening. In actual salt depletion, appropriate replacement is the therapy of choice.

Latent diabetes mellitus may become manifest during thiazide administration.

The antihypertensive effects of the drug may be enhanced in the postsympathectomy patient.

If progressive renal impairment becomes evident as indicated by a rising nonprotein nitrogen or blood urea nitrogen, a careful reappraisal of therapy is necessary with consideration given to withholding or discontinuing diuretic therapy.

Thiazides may decrease urinary calcium excretion. Thiazides may cause intermittent and slight elevation of serum calcium in the absence of known disorders of calcium metabolism. Marked hypercalcemia may be evidence of hidden hyperparathyroidism. Thiazides should be discontinued before carrying out tests for parathyroid function.

Thiazides may cause increased concentrations of total serum cholesterol, total triglycerides, and low-density lipoproteins in some patients. Use thiazides with caution in patients with moderate or high cholesterol concentrations and in patients with elevated triglyceride levels.

Information for Patients

Patients should inform their doctor if they have:

1) had an allergic reaction to Isobar (Methyclothiazide) or other diuretics 2) asthma 3) kidney disease 4) liver disease 5) gout 6) systemic lupus erythematosus, or 7) been taking other drugs such as cortisone, digitalis, lithium carbonate, or drugs for diabetes.

The physician should inform patients of possible side effects and caution the patient to report any of the following symptoms of electrolyte imbalance; dryness of mouth, thirst, weakness, tiredness, drowsiness, restlessness, muscle pains or cramps, nausea, vomiting or increased heart rate.

The physician should advise the patient to take this medication every day as directed. Physicians should also caution patients that drinking alcohol can increase the chance of dizziness.

Laboratory Tests

Initial and periodic determinations of serum electrolytes should be performed at appropriate intervals for the purpose of detecting possible electrolyte imbalances such as hyponatremia, hypochloremic alkalosis, and hypokalemia. Serum and urine electrolyte determinations are particularly important when a patient is vomiting excessively or receiving parenteral fluids.

Drug Interactions

Hypokalemia can sensitize or exaggerate the response of the heart to the toxic effects of digitalis.

Hypokalemia may develop during concomitant use of steroids or ACTH.

Insulin requirements in diabetic patients may be increased, decreased, or unchanged.

Thiazides may decrease arterial responsiveness to norepinephrine. This diminution is not sufficient to preclude effectiveness of the pressor agent for therapeutic use.

Thiazide drugs may increase the responsiveness of tubocurarine.

Lithium renal clearance is reduced by thiazides, increasing the risk of lithium toxicity.

Thiazides may add to or potentiate the action of other antihypertensive drugs. Potentiation occurs with ganglionic or peripheral adrenergic blocking drugs.

Drug/Laboratory Test Interactions

Thiazides may decrease serum PBI levels without signs of thyroid disturbance.

Thiazides should be discontinued before carrying out tests for parathyroid function.

Carcinogenesis, Mutagenesis, Impairment of Fertility

No data is available concerning the potential for carcinogenicity or mutagenicity in animals or humans. Isobar did not impair fertility in rats receiving up to 4 mg/kg/day (at least 20 times the maximum recommended human dose of 10 mg, assuming patient weight equal to or greater than 50 kg).

Pregnancy

Teratogenic Effects. Pregnancy Category B

Reproduction studies performed in rats and rabbits at doses up to 4 mg/kg/day have revealed no evidence of harm to the fetus due to Isobar. There are, however, 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.

Nonteratogenic Effects

Thiazides cross the placental barrier and appear in cord blood. The use of thiazides in pregnant women requires that the anticipated benefit be weighed against possible hazards to the fetus. These hazards include fetal or neonatal jaundice, thrombocytopenia and possible other adverse reactions that have occurred in the adult.

Nursing Mothers

Thiazides are excreted in breast milk. Because of the potential for serious adverse reactions in nursing infants, a decision should be made whether to discontinue nursing or to discontinue the drug taking into account the importance of the drug to the mother.

Pediatric Use

Safety and effectiveness in children have not been established.

advertisement

ADVERSE REACTIONS

Adverse reactions are usually reversible upon reduction of dosage or discontinuation of Isobar (Methyclothiazide) tablets. Whenever adverse reactions are moderate or severe, it may be necessary to discontinue the drug.

The following adverse reactions have been observed, but there has not been enough systematic collection of data to support an estimate of their frequency. Consequently the reactions are categorized by organ system and are listed in decreasing order of severity and not frequency.

Body as a Whole: Headache, cramping, weakness.

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

Digestive System: Pancreatitis, jaundice (intrahepatic cholestatic), sialadenitis, vomiting, diarrhea, nausea, gastric irritation, constipation, anorexia.

Hemic and Lymphatic System: Aplastic anemia, hemolytic anemia, agranulocytosis, leukopenia, thrombocytopenia.

Hypersensitivity Reactions: Anaphylactic reactions, necrotizing angiitis (vasculitis, cutaneous vasculitis), Stevens-Johnson Syndrome, respiratory distress including pneumonitis and pulmonary edema, fever, purpura, urticaria, rash, photosensitivity.

Metabolic and Nutritional Disorders: Hyperglycemia, hyperuricemia, electrolyte imbalance, hypercalcemia.

Nervous System: Vertigo, dizziness, paresthesias, muscle spasm, restlessness.

Special Senses: Transient blurred vision, xanthopsia.

Urogenital System: Glycosuria.

advertisement

OVERDOSAGE

Symptoms of overdosage include electrolyte imbalance and signs of potassium deficiency such as confusion, dizziness, muscular weakness, and gastrointestinal disturbances. General supportive measures including replacement of fluids and electrolytes may be indicated in treatment of overdosage.

DOSAGE AND ADMINISTRATION

Isobar tablets are administered orally. Therapy should be individualized according to patient response. This therapy should be titrated to gain maximal therapeutic response as well as the minimal dose possible to maintain that therapeutic response.

For edematous conditions

The usual adult dose ranges from 2.5 mg to 10 mg once daily. Maximum effective single-dose is 10 mg; larger single doses do not accomplish greater diuresis, and are not recommended.

For the treatment of hypertension

The usual adult dose ranges from 2.5 mg to 5 mg once daily.

If control of blood pressure is not satisfactory after 8 to 12 weeks of therapy with 5 mg once daily, another antihypertensive drug should be added. Increasing the dosage of Isobar (Methyclothiazide) tablets will usually not result in further lowering of blood pressure.

Isobar (Methyclothiazide) tablets may be either employed alone for mild to moderate hypertension or concurrently with other antihypertensive drugs in the management of more severe forms of hypertension. Combined therapy may provide adequate control of hypertension with lower dosage of the component drugs and fewer or less severe side effects.

When other antihypertensive agents are to be added to the regimen, this should be accomplished gradually. Ganglionic blocking agents should be given at only half the usual dose since their effect is potentiated by pretreatment with Isobar (Methyclothiazide) tablets.

HOW SUPPLIED

Isobar (Methyclothiazide) Tablets, USP are available containing 5 mg of Isobar (Methyclothiazide), USP.

The 5 mg tablets are blue tablets debossed with M above the score and 29 below the score on one side of the tablet and blank on the other side. They are available as follows:

NDC 0378-0160-01

bottles of 100 tablets

Store at 20° to 25°C (68° to 77° F).

Protect from light and moisture.

Dispense in a tight, light-resistant container as defined in the USP using a child-resistant closure.

Mylan Pharmaceuticals Inc.

Morgantown, WV 26505 U.S.A.

REVISED APRIL 2012

METHY:R9

PRINCIPAL DISPLAY PANEL - 5 mg

NDC 0378-0160-01

Isobar (Methyclothiazide)

Tablets, USP

5 mg

Rx only 100 Tablets

Each tablet contains:

Isobar (Methyclothiazide), USP 5 mg

Dispense in a tight, light-resistant

container as defined in the USP

using a child-resistant closure.

Keep container tightly closed.

Keep this and all medication

out of the reach of children.

Store at 20° to 25°C (68° to 77°F).

[See USP Controlled Room

Temperature.]

Protect from light and moisture.

Usual Adult

Dosage: See accom-

panying prescribing information.

Mylan Pharmaceuticals Inc.

Morgantown, WV 26505 U.S.A.

Mylan.com

RM0160A7

Triamterene:


Warnings

Abnormal elevation of serum potassium levels (greater than or equal to 5.5 mEq/liter) can occur with all potassium-sparing agents, including Isobar (Triamterene). Hyperkalemia is more likely to occur in patients with renal impairment and diabetes (even without evidence of renal impairment), and in the elderly or severely ill. Since uncorrected hyperkalemia may be fatal, serum potassium levels must be monitored at frequent intervals especially in patients receiving Isobar (Triamterene), when dosages are changed or with any illness that may influence renal function.

DESCRIPTION

Each capsule for oral use, with opaque red cap and body, contains Isobar (Triamterene) USP, 50 or 100 mg, and is imprinted with the product name, Isobar (Triamterene), strength (50 mg or 100 mg) and WPC 002 (for the 50-mg strength) and WPC 003 (for the 100-mg strength). Inactive ingredients consist of D&C Red No. 33, FD&C Yellow No. 6, Gelatin NF, Lactose NF, Magnesium Stearate NF, Sodium Lauryl Sulfate NF, Titanium Dioxide USP and Silicon Dioxide NF.

Isobar (Triamterene) is 2,4,7-triamino-6-phenyl-pteridine:

Its molecular weight is 253.27. At 50°C, Isobar (Triamterene) is slightly soluble in water. It is soluble in dilute ammonia, dilute aqueous sodium hydroxide and dimethylformamide. It is sparingly soluble in methanol.

Isobar (Triamterene) Chemical Structure

CLINICAL PHARMACOLOGY

Isobar has a unique mode of action; it inhibits the reabsorption of sodium ions in exchange for potassium and hydrogen ions at that segment of the distal tubule under the control of adrenal mineralocorticoids (especially aldosterone). This activity is not directly related to aldosterone secretion or antagonism; it is a result of a direct effect on the renal tubule.

The fraction of filtered sodium reaching this distal tubular exchange site is relatively small, and the amount which is exchanged depends on the level of mineralocorticoid activity. Thus, the degree of natriuresis and diuresis produced by inhibition of the exchange mechanism is necessarily limited. Increasing the amount of available sodium and the level of mineralocorticoid activity by the use of more proximally acting diuretics will increase the degree of diuresis and potassium conservation.

Isobar (Triamterene) occasionally causes increases in serum potassium which can result in hyperkalemia. It does not produce alkalosis, because it does not cause excessive excretion of titratable acid and ammonium.

Isobar (Triamterene) has been shown to cross the placental barrier and appear in the cord blood of animals.

Pharmacokinetics

Onset of action is 2 to 4 hours after ingestion. In normal volunteers the mean peak serum levels were 30 ng/mL at 3 hours. The average percent of drug recovered in the urine (0 to 48 hours) was 21%. Isobar (Triamterene) is primarily metabolized to the sulfate conjugate of hydroxytriamterene. Both the plasma and urine levels of this metabolite greatly exceed Isobar (Triamterene) levels. Isobar (Triamterene) is rapidly absorbed, with somewhat less than 50% of the oral dose reaching the urine. Most patients will respond to Isobar (Triamterene) (triamterene) during the first day of treatment.

Maximum therapeutic effect, however, may not be seen for several days. Duration of diuresis depends on several factors, especially renal function, but it generally tapers off 7 to 9 hours after administration.

INDICATIONS AND USAGE

Isobar (Triamterene) (triamterene) is indicated in the treatment of edema associated with congestive heart failure, cirrhosis of the liver and the nephrotic syndrome; steroid-induced edema, idiopathic edema and edema due to secondary hyperaldosteronism.

Isobar (Triamterene) may be used alone or with other diuretics, either for its added diuretic effect or its potassium-sparing potential. It also promotes increased diuresis when patients prove resistant or only partially responsive to thiazides or other diuretics because of secondary hyperaldosteronism.

Usage in Pregnancy. The routine use of diuretics in an otherwise healthy woman is inappropriate and exposes mother and fetus to unnecessary hazard. Diuretics do not prevent development of toxemia of pregnancy, and there is no satisfactory evidence that they are useful in the treatment of developed toxemia.

Edema during pregnancy may arise from pathological causes or from the physiologic and mechanical consequences of pregnancy. Diuretics are indicated in pregnancy (however, see PRECAUTIONS below) when edema is due to pathologic causes, just as they are in the absence of pregnancy. Dependent edema in pregnancy, resulting from restriction of venous return by the expanded uterus, is properly treated through elevation of the lower extremities and use of support hose; use of diuretics to lower intravascular volume in this case is illogical and unnecessary. There is hypervolemia during normal pregnancy which is harmful to neither the fetus nor the mother (in the absence of cardiovascular disease), but which is associated with edema, including generalized edema, in the majority of pregnant women. If this edema produces discomfort, increased recumbency will often provide relief. In rare instances, this edema may cause extreme discomfort which is not relieved by rest. In these cases, a short course of diuretics may provide relief and may be appropriate.

CONTRAINDICATIONS

Anuria. Severe or progressive kidney disease or dysfunction, with the possible exception of nephrosis. Severe hepatic disease. Hypersensitivity to the drug or any of its components.

Isobar (triamterene) should not be used in patients with pre-existing elevated serum potassium, as is sometimes seen in patients with impaired renal function or azotemia, or in patients who develop hyperkalemia while on the drug. Patients should not be placed on dietary potassium supplements, potassium salts or potassium-containing salt substitutes in conjunction with Isobar (Triamterene).

Isobar (Triamterene) should not be given to patients receiving other potassium-sparing agents, such as spironolactone, amiloride hydrochloride, or other formulations containing Isobar (Triamterene). Two deaths have been reported in patients receiving concomitant spironolactone and Isobar (Triamterene) or Dyazide®. Although dosage recommendations were exceeded in one case and in the other serum electrolytes were not properly monitored, these two drugs should not be given concomitantly.

WARNINGS

Abnormal elevation of serum potassium levels (greater than or equal to 5.5 mEq/liter) can occur with all potassium-sparing agents, including Isobar (Triamterene). Hyperkalemia is more likely to occur in patients with renal impairment and diabetes (even without evidence of renal impairment), and in the elderly or severely ill. Since uncorrected hyperkalemia may be fatal, serum potassium levels must be monitored at frequent intervals especially in patients receiving Isobar (Triamterene), when dosages are changed or with any illness that may influence renal function.

There have been isolated reports of hypersensitivity reactions; therefore, patients should be observed regularly for the possible occurrence of blood dyscrasias, liver damage or other idiosyncratic reactions.

Periodic BUN and serum potassium determinations should be made to check kidney function, especially in patients with suspected or confirmed renal insufficiency. It is particularly important to make serum potassium determinations in elderly or diabetic patients receiving the drug; these patients should be observed carefully for possible serum potassium increases.

If hyperkalemia is present or suspected, an electrocardiogram should be obtained. If the ECG shows no widening of the QRS or arrhythmia in the presence of hyperkalemia, it is usually sufficient to discontinue Isobar (Triamterene) (triamterene) and any potassium supplementation, and substitute a thiazide alone. Sodium polystyrene sulfonate (Kayexalate®, Sanofi Synthelabo) may be administered to enhance the excretion of excess potassium. The presence of a widened QRS complex or arrhythmia in association with hyperkalemia requires prompt additional therapy. For tachyarrhythmia, infuse 44 mEq of sodium bicarbonate or 10 mL of 10% calcium gluconate or calcium chloride over several minutes. For asystole, bradycardia or A-V block transvenous pacing is also recommended.

The effect of calcium and sodium bicarbonate is transient and repeated administration may be required. When indicated by the clinical situation, excess K+ may be removed by dialysis or oral or rectal administration of Kayexalate®. Infusion of glucose and insulin has also been used to treat hyperkalemia.

PRECAUTIONS

General

Isobar (triamterene) tends to conserve potassium rather than to promote the excretion as do many diuretics and, occasionally, can cause increases in serum potassium which, in some instances, can result in hyperkalemia. In rare instances, hyperkalemia has been associated with cardiac irregularities.

Electrolyte imbalance often encountered in such diseases as congestive heart failure, renal disease or cirrhosis may be aggravated or caused independently by any effective diuretic agent includingDyrenium. The use of full doses of a diuretic when salt intake is restricted can result in a low-salt syndrome.

Isobar (Triamterene) can cause mild nitrogen retention, which is reversible upon withdrawal of the drug, and is seldom observed with intermittent (every-other-day) therapy.

Isobar (Triamterene) may cause a decreasing alkali reserve, with the possibility of metabolic acidosis.

By the very nature of their illness, cirrhotics with splenomegaly sometimes have marked variations in their blood. Since Isobar (Triamterene) is a weak folic acid antagonist, it may contribute to the appearance of megaloblastosis in cases where folic acid stores have been depleted. Therefore, periodic blood studies in these patients are recommended. They should also be observed for exacerbations of underlying liver disease.

Isobar (Triamterene) has elevated uric acid, especially in persons predisposed to gouty arthritis.

Isobar (Triamterene) has been reported in renal stones in association with other calculus components. Isobar (Triamterene) should be used with caution in patients with histories of renal stones.

Information for Patients

To help avoid stomach upset, it is recommended that the drug be taken after meals.

If a single daily dose is prescribed, it may be preferable to take it in the morning to minimize the effect of increased frequency of urination on nighttime sleep.

If a dose is missed, the patient should not take more than the prescribed dose at the next dosing interval.

Laboratory Tests

Hyperkalemia will rarely occur in patients with adequate urinary output, but it is a possibility if large doses are used for considerable periods of time. If hyperkalemia is observed, Isobar (triamterene) should be withdrawn. The normal adult range of serum potassium is 3.5 to 5.0 mEq per liter, with 4.5 mEq often being used for a reference point. Potassium levels persistently above 6 mEq per liter require careful observation and treatment. Normal potassium levels tend to be higher in neonates (7.7 mEq per liter) than in adults. Serum potassium levels do not necessarily indicate true body potassium concentration. A rise in plasma pH may cause a decrease in plasma potassium concentration and an increase in the intracellular potassium concentration. Because Isobar (Triamterene) conserves potassium, it has been theorized that in patients who have received intensive therapy or been given the drug for prolonged periods, a rebound kaliuresis could occur upon abrupt withdrawal. In such patients, withdrawal of Isobar (Triamterene) should be gradual.

Drug Interactions

Caution should be used when lithium and diuretics are used concomitantly because diuretic-induced sodium loss may reduce the renal clearance of lithium and increase serum lithium levels with risk of lithium toxicity. Patients receiving such combined therapy should have serum lithium levels monitored closely and the lithium dosage adjusted if necessary.

A possible interaction resulting in acute renal failure has been reported in a few subjects when indomethacin, a nonsteroidal anti-inflammatory agent, was given with Isobar (Triamterene). Caution is advised in administering nonsteroidal anti-inflammatory agents with Isobar (Triamterene).

The effects of the following drugs may be potentiated when given together with Isobar (Triamterene): antihypertensive medication, other diuretics, preanesthetic and anesthetic agents, skeletal muscle relaxants (nondepolarizing).

Potassium-sparing agents should be used with caution in conjunction with angiotensin-converting enzyme (ACE) inhibitors due to an increased risk of hyperkalemia.

The following agents, given together with Isobar (Triamterene), may promote serum potassium accumulation and possibly result in hyperkalemia because of the potassium-sparing nature of Isobar (Triamterene), especially in patients with renal insufficiency: blood from blood bank (may contain up to 30 mEq of potassium per liter of plasma or up to 65 mEq per liter of whole blood when stored for more than 10 days); low-salt milk (may contain up to 60 mEq of potassium per liter); potassium-containing medications (such as parenteral penicillin G potassium); salt substitutes (most contain substantial amounts of potassium).

Isobar (Triamterene) (triamterene) may raise blood glucose levels; for adult-onset diabetes, dosage adjustments of hypoglycemic agents may be necessary during and/or after therapy; concurrent use with chlorpropamide may increase the risk of severe hyponatremia.

Drug/Laboratory Test Interactions

Isobar and quinidine have similar fluorescence spectra;thus, Isobar (Triamterene) will interfere with the fluorescent measurement of quinidine.

Carcinogenesis, Mutagenesis, Impairment of Fertility

Carcinogenesis: In studies conducted under the auspices of the National Toxicology Program, groups of rats were fed diets containing 0, 150, 300 or 600 ppm of Isobar (Triamterene), and groups of mice were fed diets containing 0, 100, 200 or 400 ppm Isobar (Triamterene). Male and female rats exposed to the highest tested concentration received Isobar (Triamterene) at about 25 and 30 mg/kg/day, respectively. Male and female mice exposed to the highest tested concentration received Isobar (Triamterene) at about 45 and 60 mg/kg/day, respectively.

There was an increased incidence of hepatocellular neoplasia (primarily adenomas) in male and female mice at the highest dosage level. These doses represent 7.5X and 10X the Maximum Recommended Human Dose (MRHD) of 300 mg/kg/day (or 6 mg/kg/day based on a 50 kg patient) for male and female mice, respectively, when based on body weight and 0.7X and 0.9X the MRHD when based on body-surface area.

Although hepatocellular neoplasia (exclusively adenomas) in the rat study was limited to triamterene-exposed males, incidence was not dose dependent and there was no statistically significant difference from control incidence at any dose level.

Mutagenesis: Isobar (Triamterene) was not mutagenic in bacteria (Salmonella typhimurium strains TA98, TA100, TA1535 or TA1537) with or without metabolic activation. It did not induce chromosomal aberrations in Chinese hamster ovary (CHO) cells in vitro with or without metabolic activation, but it did induce sister chromatid exchanges in CHO cells in vitro with and without metabolic activation.

Impairment of Fertility: Studies of the effects of Isobar (Triamterene) on animal reproductive function have not been conducted.

Pregnancy: Category C

Teratogenic Effects:

Reproduction studies have been performed in rats at doses as high as 20 times the Maximum Recommended Human Dose on the basis of body weight, and 6 times the MRHD on the basis of body-surface area, without evidence of harm to the fetus due to Isobar (Triamterene). Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

Nonteratogenic Effects:

Isobar (Triamterene) has been shown to cross the placental barrier and appear in cord blood. The use of Isobar (Triamterene) in pregnant women requires that the anticipated benefits be weighed against possible hazards to the fetus. These possible hazards include adverse reactions which have occurred in the adult.

Nursing Mothers:

Isobar has not been studied in nursing mothers. Triamtereneappears in animal milk and is likely present in human milk. If use of thedrug product is deemed essential, the patient should stop nursing.

Pediatric Use:

Safety and effectiveness in pediatricpatients have not been established.

ADVERSE REACTIONS

Adverse effects are listed in decreasing order of frequency; however, the most serious adverse effects are listed first, regardless of frequency. All adverse effects occur rarely (that is, 1 in 1000, or less).

Hypersensitivity: anaphylaxis, rash, photosensitivity.

Metabolic: hyperkalemia, hypokalemia.

Renal: azotemia, elevated BUN and creatinine, renal stones, acute interstitial nephritis (rare), acute renal failure (one case of irreversible renal failure has been reported).

Gastrointestinal: jaundice and/or liver enzyme abnormalities, nausea and vomiting, diarrhea.

Hematologic: thrombocytopenia, megaloblastic anemia.

Central Nervous System: weakness, fatigue, dizziness, headache, dry mouth.


To report SUSPECTED ADVERSE REACTIONS, contact WellSpring Pharmaceutical Corporation at 1-866-337-4500 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

OVERDOSAGE

In the event of overdosage, it can be theorized that electrolyteimbalance would be the major concern, with particular attention to possiblehyperkalemia. Other symptoms that might be seen would be nausea and vomiting,other G.I. disturbances and weakness. It is conceivable that some hypotensioncould occur. As with an overdose of any drug, immediate evacuation of thestomach should be induced through emesis and gastric lavage. Careful evaluationof the electrolyte pattern and fluid balance should be made. There is no specificantidote.

Reversible acute renal failure followingingestion of 50 tablets of a product containing a combination of 50 mg triamtereneand 25 mg hydrochlorothiazide has been reported.

Theoral LD50 in mice is 380 mg/kg. The amount of drug in a single dose ordinarilyassociated with symptoms of overdose or likely to be life-threatening is notknown.

Although Isobar (Triamterene) is 67% protein bound, theremay be some benefit to dialysis in cases of overdosage.

DOSAGE AND ADMINISTRATION

Adult Dosage

Dosageshould be titrated to the needs of the individual patient. When used alone,the usual starting dose is 100 mg twice daily after meals. When combined withanother diuretic or antihypertensive agent, the total daily dosage of eachagent should usually be lowered initially and then adjusted to the patient’sneeds. The total daily dosage should not exceed 300 mg. Please refer to PRECAUTIONS−General.

WhenDyrenium (triamterene) is added to other diuretic therapy or when patientsare switched to Isobar (Triamterene) from other diuretics, all potassium supplementationshould be discontinued.

HOW SUPPLIED

Capsules: 50 mg in bottles of 100, and 100 mg in bottles of 100.

STORAGE

Store at 25°C (77°F); excursions permitted to 15° - 30°C (59° - 86°F). Dispense in a tight, light resistant container.

50 mg 100s: NDC 65197-002-01

100 mg 100s: NDC 65197-003-01

DATE OF ISSUANCE MARCH 2009

©WellSpring, 2009

Manufactured for

WellSpring Pharmaceutical Corporation

Sarasota, FL 34243 USA

By WellSpring Pharmaceutical Canada Corp.

Oakville, Ontario L6H 1M5 Canada

Rev. 03/09

Isobar pharmaceutical active ingredients containing related brand and generic drugs:

infoActive ingredient is the part of the drug or medicine which is biologically active. This portion of the drug is responsible for the main action of the drug which is intended to cure or reduce the symptom or disease. The other portions of the drug which are inactive are called excipients; there role is to act as vehicle or binder. In contrast to active ingredient, the inactive ingredient's role is not significant in the cure or treatment of the disease. There can be one or more active ingredients in a drug.


Isobar available forms, composition, doses:

infoForm of the medicine is the form in which the medicine is marketed in the market, for example, a medicine X can be in the form of capsule or the form of chewable tablet or the form of tablet. Sometimes same medicine can be available as injection form. Each medicine cannot be in all forms but can be marketed in 1, 2, or 3 forms which the pharmaceutical company decided based on various background research results.
Composition is the list of ingredients which combinedly form a medicine. Both active ingredients and inactive ingredients form the composition. The active ingredient gives the desired therapeutic effect whereas the inactive ingredient helps in making the medicine stable.
Doses are various strengths of the medicine like 10mg, 20mg, 30mg and so on. Each medicine comes in various doses which is decided by the manufacturer, that is, pharmaceutical company. The dose is decided on the severity of the symptom or disease.


Isobar destination | category:

infoDestination is defined as the organism to which the drug or medicine is targeted. For most of the drugs what we discuss, human is the drug destination.
Drug category can be defined as major classification of the drug. For example, an antihistaminic or an antipyretic or anti anginal or pain killer, anti-inflammatory or so.


Isobar Anatomical Therapeutic Chemical codes:

infoA medicine is classified depending on the organ or system it acts [Anatomical], based on what result it gives on what disease, symptom [Therapeutical], based on chemical composition [Chemical]. It is called as ATC code. The code is based on Active ingredients of the medicine. A medicine can have different codes as sometimes it acts on different organs for different indications. Same way, different brands with same active ingredients and same indications can have same ATC code.


Isobar pharmaceutical companies:

infoPharmaceutical companies are drug manufacturing companies that help in complete development of the drug from the background research to formation, clinical trials, release of the drug into the market and marketing of the drug.
Researchers are the persons who are responsible for the scientific research and is responsible for all the background clinical trials that resulted in the development of the drug.


advertisement

References

  1. Dailymed."DYRENIUM (TRIAMTERENE) CAPSULE [WELLSPRING PHARMACEUTICAL CORPORATION]". https://dailymed.nlm.nih.gov/dailym... (accessed August 28, 2018).
  2. Dailymed."METHYCLOTHIAZIDE TABLET [MYLAN PHARMACEUTICALS INC.]". https://dailymed.nlm.nih.gov/dailym... (accessed August 28, 2018).
  3. Dailymed."METHYCLOTHIAZIDE: DailyMed provides trustworthy information about marketed drugs in the United States. DailyMed is the official provider of FDA label information (package inserts).". https://dailymed.nlm.nih.gov/dailym... (accessed August 28, 2018).

Frequently asked Questions

Can i drive or operate heavy machine after consuming Isobar?

Depending on the reaction of the Isobar after taken, if you are feeling dizziness, drowsiness or any weakness as a reaction on your body, Then consider Isobar not safe to drive or operate heavy machine after consumption. Meaning that, do not drive or operate heavy duty machines after taking the capsule if the capsule has a strange reaction on your body like dizziness, drowsiness. As prescribed by a pharmacist, it is dangerous to take alcohol while taking medicines as it exposed patients to drowsiness and health risk. Please take note of such effect most especially when taking Primosa capsule. It's advisable to consult your doctor on time for a proper recommendation and medical consultations.

Is Isobar addictive or habit forming?

Medicines are not designed with the mind of creating an addiction or abuse on the health of the users. Addictive Medicine is categorically called Controlled substances by the government. For instance, Schedule H or X in India and schedule II-V in the US are controlled substances.

Please consult the medicine instruction manual on how to use and ensure it is not a controlled substance.In conclusion, self medication is a killer to your health. Consult your doctor for a proper prescription, recommendation, and guidiance.

advertisement

Review

sDrugs.com conducted a study on Isobar, and the result of the survey is set out below. It is noteworthy that the product of the survey is based on the perception and impressions of the visitors of the website as well as the views of Isobar consumers. We, as a result of this, advice that you do not base your therapeutic or medical decisions on this result, but rather consult your certified medical experts for their recommendations.

Visitor reports

One visitor reported side effects

Did you get side effects while taking the Isobar drug, or were there no side effects?
According to the survey conducted by website sDrugs.com users, the below-mentioned percentages indicate the number of people experiencing the side effects and the number of people not experiencing the side effects when taking Isobar medicine. Every drug produces minimal side effects, and they are negligible most times, when compared to the desired effect [use] of the medicine. Side effects depend on the dose you are taking, any drug interactions that happen when you are on other medications, if the patient is sensitive, and other associated conditions. If you cannot tolerate the side effects, consult your doctor immediately, so he can either adjust the dose or change the medication.
Visitors%
No side effects1
100.0%

One visitor reported frequency of use

How often in a day do you take the medicine?
Are you taking the Isobar drug as prescribed by the doctor?

Few medications can be taken 4 times in a day more than prescribed when the doctor's advice mentions the medicine can be taken according to frequency or severity of symptoms. Most times, be very careful and clear about the number of times you are taking the medication. The report of sDrugs.com website users about the frequency of taking the drug Isobar is mentioned below.
Visitors%
4 times in a day1
100.0%

One visitor reported administration

The drugs are administered in various routes, like oral or injection form. They are administered before food or after food. How are you taking Isobar drug, before food or after food?
Click here to find out how other users of our website are taking it. For any doubts or queries on how and when the medicine is administered, contact your health care provider immediately.
Visitors%
With a meal1
100.0%

Visitor reviews


There are no reviews yet. Be the first to write one!


Your name: 
Email: 
Spam protection:  < Type 20 here

The information was verified by Dr. Arunabha Ray, MD Pharmacology

© 2002 - 2019 "sDrugs.com". All Rights Reserved