Twincard 50 mg+25 mg

INDICATIONS

This combination 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.

PHARMACOLOGY

Atenolol and chlorthalidone have been used singly and concomitantly for the treatment of hypertension. 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 drugs. Atenolol is a beta1-selective (cardioselective) beta-adrenergic receptor blocking agent that provides-

reduction in resting and exercise heart rates and cardiac output
reduction of systolic and diastolic blood pressure at rest and on exercise
reduction in reflex orthostatic tachycardia.

Chlorthalidone is a monosulfonamyl diuretic with prolonged action and low toxicity. It produces diuresis with greatly increased excretion of sodium and chloride at distal convoluted tubule of the nephron.

DOSAGE & ADMINISTRATION

The initial dose is Atenolol 50 mg and Chlorthalidone 25 mg once a day. If an optimal response is not achieved, 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. Atenolol is excreted via kidneys and therefore dosage should be adjusted in cases of severe impairment of renal function.Use in elderly: Clinical studies of Atenolol & Chlorthalidone combination did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects.

INTERACTION

This combination may potentiate the action of other antihypertensive agents used concominantly. Concominant use with catecholamine depletor (eg, reserpine) may cause hypotension and/or marked bradycardia
Calcium channel blockers, Amiodarone may have an additive effect when given with this combination.
Concomitant use of prostaglandin synthase inhibiting drugs, eg, indomethacin, may decrease the hypotensive effects of beta blockers.
Both digitalis glycosides and beta-blockers slow atrioventricular conduction and decrease heart rate. Concomitant use can increase the risk of bradycardia.

SIDE EFFECTS

The adverse effects observed for this combination are essentially the same as those seen with the individual components. Atenolol: Bradycardia, Cold Extremities, Postural Hypotension, Leg Pain, Dizziness, Vertigo, Light Headedness, Tiredness, Fatigue, Lethargy, Drowsiness, Depression, Dreaming, Diarrhea, Nausea, Wheeziness, Dyspnea, Chlorthalidone Orthostatic hypotension, anorexia, gastric irritation, vomiting, cramping, constipation, vertigo, purpura, photosensitivity, rash, urticaria, hyperglycemia, glycosuria, hyperuricemia, muscle spasm, weakness, restlessness.

PREGNANCY & LACTATION

Pregnancy Category D. Caution should be exercised when this drug is administered to a woman who is breastfeeding.

PRECAUTIONS & WARNINGS

This combination may aggravate peripheral arterial circulatory disorders. Periodic determination of serum electrolytes to detect possible electrolyte imbalance should be performed at appropriate intervals.

THERAPEUTIC CLASS

Combined antihypertensive preparations

STORAGE CONDITIONS

Store in cool and dry place, protected from light.