Atenolol + Chlorthalidone

Indications

Atenolol & Chlorthalidoneis combination is indicated for the treatment of hypertension.

Pharmacology

Atenolol is a beta1-selective (cardio selective) beta-adrenergic receptor blocking agentwithout membrane stabilizing or intrinsic sympathomimetic (partial agonist) activities.This preferential effect is not absolute, however, and at higher doses, Atenolol inhibitsbeta-2-adrenoreceptors, chiefly located in the bronchial and vascular musculature.Chlorthalidone

Chlorthalidone is a monosulfonamyl double ring system which differs chemically fromthiazide diuretics in that a double ring system is incorporated in its' structure. It is an oraldiuretic with prolonged action and low toxicity. The diuretic of the drug occurs within 2 hours of an oral dose. It produces diuresis with greatly increased excretion of sodium andchloride. At maximal therapeutic dosage, Chlorthalidone is approximately equal in itsdiuretic effect to comparable maximal therapeutic doses of benzothiadiazine diuretics.The site of action appears to be the cortical diluting segment of the ascending limb of Henle's loop of the nephron.

Dosage And Administration

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 Chlorthalidone 25 & Atenolol 50 mg once a day. If an optimal response is not achieved, the dosage should be increased to one Chlorthalidone 25 & Atenolol 100 mg once a day. Dose of two tablets once daily should not be used as initial therapy in elderly patients.

Interaction

Atenolol and Chlorthalidone combination may potentiate the action of other antihypertensives such as Clonidine, Diltiazem. Prostaglandin synthase inhibiting drugs e.g. Indomethacin may decrease the hypotensive effects of beta-blockers. This tablet should not be given with Lithium due to high risk of Lithium toxicity.

Contraindications

Atenolol and Chlorthalidone combination is contraindicated in hypersensitivity to this product or to sulfonamide-derived drugs. It is also contraindicated in patients with sinus bradycardia, heart block greater than first degree, cardiogenic shock, overt cardiac failure and anuria.

Side Effects

Atenolol and Chlorthalidone combination is usually well tolerated. Most adverse effects have been mild and transient. However dizziness, fatigue, vertigo, nausea, diarrhea and bradycardia have been reported rarely.

Pregnancy And Lactation

Pregnancy Category D. Atenolol & Chlorthalidone combination can cause fetal harm to the developing baby and may appear in breast milk. So it should not be taken during pregnancy & lactation.

Precautions And Warnings

Atenolol and Chlorthalidone combination should be given with caution to patients with severe renal impairment, uncontrolled heart failure, impaired hepatic function or liver disease.

Overdose Effects

No specific information is available with regard to over dosage and Atenolol and Chlorthalidone in humans. Treatment should be symptomatic and supportive and directed to the removal of any unabsorbed drug by induced emesis, or administration of activated charcoal. Atenolol can be removed from the general circulation by hemodialysis. Further consideration should be given to dehydration, electrolyte imbalance and hypotension by established procedures.

Therapeutic Class

Combined antihypertensive preparations

Use in special populations

Pediatric Uses: Safety and effectiveness in pediatric patients have not been established

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.

Storage Conditions

Store in cool and dry place, protected from light.

Available Brand Names