TENORETIC- atenolol and chlorthalidone tablet
Almatica Pharma Inc.
atenolol-structurechlorthalidone-structurelabel-50mg-25mg-90label-100mg-25mg-90
DESCRIPTION
TENORETIC� (atenolol and chlorthalidone) is for the treatment of hypertension. It combines the antihypertensive activity of two agents: a beta1 -selective (cardioselective) hydrophilic blocking agent (atenolol, TENORMIN�) and a monosulfonamyl diuretic (chlorthalidone). Atenolol is Benzeneacetamide, 4-[2'-hydroxy-3'-[(1-methylethyl) amino] propoxy]-.
Atenolol (free base) is a relatively polar hydrophilic compound with a water solubility of 26.5 mg/mL at 37� C. It is freely soluble in 1N HCl (300 mg/mL at 25�C) and less soluble in chloroform (3 mg/mL at 25�C).
Chlorthalidone is 2-Chloro-5-(1-hydroxy-3-oxo-1-isoindolinyl) benzene sulfonamide:
Chlorthalidone has a water solubility of 12 mg/100 mL at 20�C.
Each TENORETIC 100 Tablet contains:
Atenolol (TENORMIN�)�������������100 mg
Chlorthalidone������������������.. 25 mg
Each TENORETIC 50 Tablet contains:
Atenolol (TENORMIN�)�������������..50 mg
Chlorthalidone�������������������.25 mg
Inactive ingredients: magnesium stearate, microcrystalline cellulose, povidone, sodium starch glycolate.
CLINICAL PHARMACOLOGY
Tenoretic
Atenolol and chlorthalidone have been used singly and concomitantly for the treatment of hypertension. The antihypertensive effects of these agents are additive, and studies have shown that there is no interference with bioavailability when these agents are given together in the single combination tablet. Therefore, this combination provides a convenient formulation for the concomitant administration of these two entities. In patients with more severe hypertension, TENORETIC may be administered with other antihypertensives such as vasodilators.
Atenolol
Atenolol is a beta1 -selective (cardioselective) beta-adrenergic receptor blocking agent without membrane stabilizing or intrinsic sympathomimetic (partial agonist) activities. This preferential effect is not absolute, however, and at higher doses, atenolol inhibits beta2 -adrenoreceptors, chiefly located in the bronchial and vascular musculature.
INDICATIONS AND USAGE
TENORETIC is indicated for the treatment of hypertension, to lower blood pressure. Lowering blood pressure lowers the risk of fatal and non-fatal cardiovascular events, primarily strokes and myocardial infarctions. These benefits have been seen in controlled trials of antihypertensive drugs from a wide variety of pharmacologic classes including atenolol and chlorthalidone.
Atenolol
Atenolol has been shown to produce a dose-related increase in embryo/fetal resorptions in rats at doses equal to or greater than 50 mg/kg/day or 25 or more times the maximum recommended human antihypertensive dose. Although similar effects were not seen in rabbits, the compound was not evaluated in rabbits at doses above 25 mg/kg/day or 12.5 times the maximum recommended human antihypertensive dose.
Chlorthalidone
Thiazides cross the placental barrier and appear in cord blood. The use of chlorthalidone and related drugs in pregnant women requires that the anticipated benefits of the drug be weighed against possible hazards to the fetus. These hazards include fetal or neonatal jaundice, thrombocytopenia and possibly other adverse reactions which have occurred in the adult.
DOSAGE AND ADMINISTRATION
DOSAGE MUST BE INDIVIDUALIZED. (See INDICATIONS AND USAGE.)
Chlorthalidone is usually given at a dose of 25 mg daily; the usual initial dose of atenolol is 50 mg daily. Therefore, the initial dose should be one TENORETIC 50 tablet given once a day. If an optimal response is not achieved, the dosage should be increased to one TENORETIC 100 tablet given once a day.
When necessary, another antihypertensive agent may be added gradually beginning with 50 percent of the usual recommended starting dose to avoid an excessive fall in blood pressure.
Since atenolol is excreted via the kidneys, dosage should be adjusted in cases of severe impairment of renal function. No significant accumulation of atenolol occurs until creatinine clearance falls below 35 mL/min/1.73m2 (normal range is 100-150 mL/min/1.73m2); therefore, the following maximum dosages are recommended for patients with renal impairment.
