Atenolol and Chlorthalidone (Page 5 of 5)

Clinical Laboratory Test Findings

Clinically important changes in standard laboratory parameters were rarely associated with the administration of atenolol and chlorthalidone. The changes in laboratory parameters were not progressive and usually were not associated with clinical manifestations. The most common changes were increases in uric acid and decreases in serum potassium.


No specific information is available with regard to overdosage 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.


Overdosage with atenolol has been reported with patients surviving acute doses as high as 5 g. One death was reported in a man who may have taken as much as 10 g acutely.

The predominant symptoms reported following atenolol overdose are lethargy, disorder of respiratory drive, wheezing, sinus pause, and bradycardia. Additionally, common effects associated with overdosage of any beta-adrenergic blocking agent are congestive heart failure, hypotension, bronchospasm, and/or hypoglycemia. Other treatment modalities should be employed at the physician’s discretion and may include:

BRADYCARDIA: Atropine 1-2 mg intravenously. If there is no response to vagal blockade, give isoproterenol cautiously. In refractory cases, a transvenous cardiac pacemaker may be indicated. Glucagon in a 10 mg intravenous bolus has been reported to be useful. If required, this may be repeated or followed by an intravenous infusion of glucagon 1-10 mg/h depending on response.

HEART BLOCK (SECOND OR THIRD DEGREE): Isoproterenol or transvenous pacemaker.

CONGESTIVE HEART FAILURE: Digitalize the patient and administer a diuretic. Glucagon has been reported to be useful.

HYPOTENSION: Vasopressors such as dopamine or norepinephrine (levarterenol). Monitor blood pressure continuously.

BRONCHOSPASM: A beta2 -stimulant such as isoproterenol or terbutaline and/or aminophylline.

HYPOGLYCEMIA: Intravenous glucose.

ELECTROLYTE DISTURBANCE: Monitor electrolyte levels and renal function. Institute measures to maintain hydration and electrolytes.

Based on the severity of symptoms, management may require intensive support care and facilities for applying cardiac and respiratory support.


Symptoms of chlorthalidone overdose include nausea, weakness, dizziness and disturbances of electrolyte balance.


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 atenolol and chlorthalidone 50 mg-25 mg tablet given once a day. If an optimal response is not achieved, the dosage should be increased to one atenolol and chlorthalidone 100 mg-25 mg tablet given once a day.

When necessary, another antihypertensive agent may be added gradually beginning with 50% 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/1.73 m2 (normal range is 100-150 mL/min/1.73 m2); therefore, the following maximum dosages are recommended for patients with renal impairment.

Creatinine Clearance Atenolol Elimination
(mL/min/1.73 m2) Half-life (hrs) Maximum Dosage
15-35 16-27 50 mg daily
<15 >27 50 mg every other day


Atenolol and Chlorthalidone Tablets USP, 50 mg-25 mg are 10/32”, scored, round, white tablets imprinted DAN 5782 supplied in bottles of 30, 60 and 90.

Store at 20°-25°C (68°-77°F) [See USP Controlled Room Temperature.] Dispense in a well-closed, light-resistant container with a child-resistant closure. Protect from heat, light and moisture. Protect from heat, light and moisture.

Manufactured by:
Watson Laboratories, Inc.
Corona, CA 92880 USA

Distributed by:
Watson Pharma, Inc.
Parsippany, NJ 07054 USA

Repackaged By :
Aidarex Pharmaceuticals LLC,
Corona, CA 92880

Revised: December 2012


NDC 33261-0942-30
Atenolol and
Tablets USP
50mg/25mg30 Tablets Rx only

(click image for full-size original)
ATENOLOL AND CHLORTHALIDONE atenolol and chlorthalidone tablet
Product Information
Product Type HUMAN PRESCRIPTION DRUG Item Code (Source) NDC:33261-942(NDC:0591-5782)
Route of Administration ORAL DEA Schedule
Active Ingredient/Active Moiety
Ingredient Name Basis of Strength Strength
Inactive Ingredients
Ingredient Name Strength
Product Characteristics
Color WHITE Score 2 pieces
Shape ROUND Size 8mm
Flavor Imprint Code DAN;5782
# Item Code Package Description Multilevel Packaging
1 NDC:33261-942-30 30 TABLET (30 TABLET) in 1 BOTTLE, PLASTIC None
2 NDC:33261-942-60 60 TABLET (60 TABLET) in 1 BOTTLE, PLASTIC None
3 NDC:33261-942-90 90 TABLET (90 TABLET) in 1 BOTTLE, PLASTIC None
Marketing Information
Marketing Category Application Number or Monograph Citation Marketing Start Date Marketing End Date
ANDA ANDA073665 08/01/1992
Labeler — Aidarex Pharmaceuticals LLC (801503249)

Revised: 11/2013 Aidarex Pharmaceuticals LLC

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