Atechlor50 mg+25 mg

Atechlor is a fixed-dose combination of a beta-1 selective adrenergic blocking agent (atenolol) and a thiazide-like diuretic (chlorthalidone), indicated for the following:

Established/FDA-approved use

• Hypertension: Atechlor is indicated for the treatment of hypertension in patients whose blood pressure is not adequately controlled on either component alone, or as initial therapy in patients likely to need multiple drugs to achieve their blood pressure goal. It lowers blood pressure and thereby reduces the risk of fatal and non-fatal cardiovascular events such as stroke and myocardial infarction.

Not first-line for these uses

Atechlor is not intended as initial therapy for hypertension in patients whose blood pressure can be controlled on a single agent; it is used specifically as combination therapy once monotherapy with either component has proven insufficient, or when a patient is already stable on the equivalent individual doses of atenolol and chlorthalidone.

Each tablet of Atenolol + Chlorthalidone contains atenolol and chlorthalidone in one of the following fixed-dose combinations:

• Atenolol 50 mg + Chlorthalidone 25 mg
• Atenolol 100 mg + Chlorthalidone 25 mg

Atechlor is an oral fixed-dose combination antihypertensive medicine that pairs atenolol, a beta-1 selective (cardioselective) adrenergic receptor blocking agent, with chlorthalidone, a thiazide-like diuretic. The two components lower blood pressure through complementary mechanisms — atenolol reduces cardiac output and renin release, while chlorthalidone promotes renal excretion of sodium and water — giving an additive antihypertensive effect that is generally greater than either drug used alone.

Atechlor is used once the blood pressure control achieved with a single antihypertensive agent is inadequate, or in patients who are expected to require combination therapy from the outset.

Atechlor belongs to the therapeutic class of fixed-dose combination antihypertensives, combining a beta-1 selective adrenergic blocker (beta-blocker) with a thiazide-like diuretic.

Atenolol + Chlorthalidone combines two antihypertensive agents with distinct and complementary mechanisms of action:

• Atenolol is a beta-1 selective (cardioselective) adrenergic receptor blocking agent. It reduces heart rate, myocardial contractility, and cardiac output, and it suppresses renin release from the kidney, all of which contribute to lowering blood pressure. Selectivity for beta-1 receptors is relative and diminishes at higher doses.
• Chlorthalidone is a thiazide-like diuretic that acts on the distal convoluted tubule of the nephron, inhibiting sodium and chloride reabsorption. This increases urinary excretion of sodium, chloride, and water, reducing plasma and extracellular fluid volume, which lowers blood pressure. It also increases excretion of potassium and magnesium.

Given together, the two agents produce an additive antihypertensive effect. There is no significant pharmacokinetic interaction between atenolol and chlorthalidone that affects the bioavailability of either component when combined in Atenolol + Chlorthalidone.

Atechlor is taken orally, once daily, at approximately the same time each day, with or without food. The tablet should be swallowed whole with a glass of water and should not be crushed or chewed unless a physician or pharmacist advises otherwise. If a dose is missed, it should be taken as soon as remembered unless it is nearly time for the next dose, in which case the missed dose should be skipped — a double dose should never be taken to make up for a missed one.

Atechlor has been associated with the following clinically significant drug interactions:

Side effects of Atechlor arise from both the beta-blocker and diuretic components.

Patients should seek prompt medical advice for symptoms such as very slow heartbeat, fainting, significant swelling, difficulty breathing, or signs of severe electrolyte disturbance (severe muscle weakness, confusion, irregular heartbeat).

Atechlor should be used in pregnancy only if clearly needed and if the potential benefit justifies the potential risk to the fetus; a physician must be consulted before use. Beta-blockers such as the atenolol component have been associated with fetal growth restriction, bradycardia, and hypoglycemia in the newborn when used in later pregnancy, and thiazide diuretics such as chlorthalidone can cause fetal or neonatal jaundice, thrombocytopenia, and reduced placental perfusion. Atechlor is generally not recommended during pregnancy, particularly in the second and third trimesters, unless no safer alternative is suitable.

Both atenolol and chlorthalidone pass into breast milk. Atechlor should be used during breastfeeding only under medical supervision, with the infant monitored for signs of beta-blockade (poor feeding, slow heart rate) if the mother continues therapy; consult a physician before breastfeeding while taking this medicine.

The following precautions apply when using Atechlor:

• Abrupt discontinuation: Do not stop Atechlor suddenly, especially in patients with ischemic heart disease, as this may precipitate rebound angina, myocardial infarction, or ventricular arrhythmia due to the beta-blocker component. The dose should be tapered gradually over one to two weeks.
• Electrolyte and fluid balance: The chlorthalidone component can cause hypokalemia, hyponatremia, hypomagnesemia, and hypercalcemia. Periodic monitoring of serum electrolytes is recommended, particularly in patients on digitalis or at risk of arrhythmia.
• Diabetes mellitus: The atenolol component may mask signs of hypoglycemia such as tachycardia, and the chlorthalidone component may worsen glycemic control; blood glucose should be monitored closely.
• Bronchospastic disease: Although atenolol is relatively beta-1 selective, this selectivity is not absolute; Atechlor should be used with caution in patients with a history of asthma or chronic obstructive pulmonary disease, at the lowest effective dose.
• Gout and hyperuricemia: The chlorthalidone component can raise serum uric acid and may precipitate acute gout in susceptible patients.
• Renal and hepatic impairment: Use with caution; thiazide-type diuretics may be ineffective in severe renal impairment, and dose adjustment of the atenolol component may be needed in renal insufficiency.
• Peripheral vascular disease: Beta-blockers such as the atenolol component may aggravate symptoms of peripheral arterial circulatory disorders.
• Anesthesia and surgery: The continued beta-blockade from the atenolol component reduces the risk of arrhythmias during anesthesia but the anesthetist should be informed that the patient is taking Atechlor.
• Thyrotoxicosis: Beta-blockade may mask signs of hyperthyroidism such as tachycardia; abrupt withdrawal may precipitate thyroid storm.

Overdose of Atechlor may cause pronounced bradycardia, hypotension, acute cardiac failure, bronchospasm, and significant fluid and electrolyte depletion (dehydration, hypokalemia, hyponatremia). Symptoms of overdose require immediate medical attention — a physician, hospital emergency department, or poison control center should be contacted right away.

Management is supportive and symptomatic and should only be carried out under medical supervision, and may include gastric decontamination if performed soon after ingestion, cardiac monitoring, and treatment of bradycardia, hypotension, bronchospasm, or electrolyte disturbances as clinically indicated. Do not attempt to manage a suspected overdose of Atechlor at home.

Store at room temperature (below 30°C), away from light and moisture. Keep out of reach of children.

• Renal impairment: Use Atechlor with caution. In severe renal impairment (creatinine clearance below approximately 35 mL/min/1.73m²), thiazide-type diuretics like the chlorthalidone component may be ineffective, and dosing intervals for the atenolol component may need to be extended with close monitoring.
• Hepatic impairment: Limited data are available; use with caution and monitor for adverse effects.
• Elderly patients: May be more sensitive to blood-pressure-lowering and electrolyte effects; start at the lower dose and monitor renal function and electrolytes.
• Diabetic patients: Use with caution as the atenolol component can mask hypoglycemia symptoms and the chlorthalidone component can worsen glycemic control; monitor blood glucose regularly.
• Pediatric patients: Safety and effectiveness of Atechlor have not been established in children; its use is not recommended in this population.

Atechlor is typically used as long-term, ongoing therapy for chronic hypertension, since blood pressure control needs to be sustained rather than treated for a fixed short course. The duration of treatment should be determined by a physician based on blood pressure response, tolerability, and overall cardiovascular risk, with periodic follow-up to reassess the need for continued therapy or dose adjustment. Atechlor should never be discontinued abruptly without medical advice.

Atenolol + Chlorthalidone is a fixed-dose combination of a beta-1 selective adrenergic blocking agent (beta-blocker) and a thiazide-like diuretic, classified overall as a combination antihypertensive agent.

Atenolol + Chlorthalidone lowers blood pressure through the combined action of its two components. The atenolol component selectively blocks beta-1 adrenergic receptors, primarily in the heart, reducing heart rate, cardiac contractility, cardiac output, and renin secretion. The chlorthalidone component inhibits sodium and chloride reabsorption in the distal convoluted tubule of the nephron, promoting diuresis and natriuresis, which reduces plasma volume. The combined effect of reduced cardiac output and reduced circulating volume produces a greater antihypertensive effect than either component alone.

D

The safety and effectiveness of Atechlor in pediatric patients have not been established. Atechlor is therefore not recommended for use in children, and alternative antihypertensive therapy with an established pediatric safety profile should be considered when treatment is needed in this age group.