FDA-filed SPL labeling · retrieved through openFDA

Atenolol / Chlorthalidone

Atenolol/chlorthalidone is a combination beta-blocker and diuretic tablet used to treat high blood pressure.

Brand name Tenoretic
Drug classes ⓘ Beta-adrenergic Blocker
Rx Form 1 Route Oral
Dr. Brian Staiger, PharmD, BCPS
Reviewed by Last reviewed Aug 31, 2026
🧬 Where this information comes from Click to expand

The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 11 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →

At a glance
Linked label effectiveApr 13, 2026
Clinical labels in scope ⓘ11
AvailabilityRx
Earliest approval/marketing year ⓘ1992
FDA-listed product records ⓘ54
Boxed warningNone found in compared labels
How we combine label and product data →
✓No current FDA shortage listed · checked Sep 22, 2026
⭐ Atenolol / Chlorthalidone at a glance The quick version — the full detail is in the Patient Information Guide below.
💊
HelloPharmacist Editorial Team Bottom Line
Atenolol/chlorthalidone is a once-daily combination tablet used to treat high blood pressure when two medicines working together are needed. Never stop it suddenly — especially if you have heart disease — and keep your doctor informed about any changes in how you feel. Managing blood pressure well with this medication significantly reduces your risk of stroke and heart attack.
How we write & review this content — our editorial policy →

📖 Atenolol / Chlorthalidone: Patient Information Guide

A plain-language walkthrough of Atenolol / Chlorthalidone — what it treats, how it works, how it’s taken, side effects, warnings and interactions. Tap any section to expand it.

🎯What it's used for▾

Atenolol/chlorthalidone tablets treat high blood pressure (hypertension) and help reduce the risk of serious cardiovascular complications.

  • Atenolol And Chlorthalidone tablets are indicated to treat hypertension and lower blood pressure, reducing the risk of stroke and heart attack.
  • Tenoretic tablets are indicated to treat hypertension and lower blood pressure, reducing the risk of stroke and heart attack.
  • Both products are fixed-dose combination tablets and are not for initial (first-ever) treatment of high blood pressure — they are used when the specific combination dose has already been established as right for the patient.
  • In patients with more severe high blood pressure, either product may be used alongside additional blood pressure medicines such as vasodilators, as directed by a prescriber.
⚙️How it works▾

Atenolol is a cardioselective (heart-focused) beta-blocker — it preferentially blocks beta-1 receptors in the heart, slowing heart rate and reducing cardiac output, which lowers blood pressure. Chlorthalidone is a thiazide-type diuretic that removes excess fluid and sodium through the kidneys, further reducing blood pressure. The two mechanisms work together, and their blood-pressure-lowering effects are additive.

At higher doses, atenolol's selectivity for the heart is not absolute — it can also affect beta-2 receptors in the lungs and blood vessels, which is why caution is needed in people with asthma or breathing problems. The antihypertensive effect of atenolol does not appear to diminish with long-term use.

💊How it's taken▾

Both Atenolol And Chlorthalidone tablets and Tenoretic tablets are taken by mouth once daily. Dosing must be individualized by your prescriber — do not adjust it on your own. Patients with significantly reduced kidney function may require a lower dose or less frequent dosing, as atenolol is cleared mainly by the kidneys.

  • Take at the same time each day as directed by your doctor.
  • Do not stop taking it abruptly — always consult your prescriber before stopping.
  • If another blood pressure medicine is added, it is typically started at half the usual dose to prevent blood pressure from dropping too quickly.
🤒Side effects — in detail▾

Most people tolerate this medication well; side effects tend to be mild and temporary.

  • Slow heart rate (bradycardia)
  • Cold hands or feet
  • Dizziness or lightheadedness
  • Tiredness or fatigue
  • Nausea or diarrhea
  • Low blood pressure when standing (postural hypotension)
  • Shortness of breath or wheezing
  • Depression or vivid dreams

More serious but less common effects reported after marketing include hallucinations, significant low blood pressure with fainting, reversible hair loss, blood count changes (such as low platelets), and signs of a lupus-like reaction. Call your doctor promptly if you notice any of these.

⚠️Warnings & precautions▾
  • Do not stop suddenly: Abrupt withdrawal — especially in patients with coronary artery disease — can trigger worsening chest pain or heart attack. Always taper under medical supervision.
  • Heart failure risk: Beta-blockers can worsen cardiac function over time. At the first sign of worsening heart failure symptoms (breathlessness, swelling), contact your doctor immediately.
  • Diabetes and low blood sugar: This drug can mask the fast heartbeat that usually warns you of low blood sugar. Extra monitoring is essential if you have diabetes, are fasting, or are having surgery.
  • Breathing problems: Patients with asthma or other bronchospastic lung disease should generally not use beta-blockers. Use only if no other option exists, and with very close monitoring.
  • Pregnancy: Atenolol can harm a developing baby, including causing growth restriction. If you are pregnant or planning to become pregnant, discuss this with your doctor right away.
  • Kidney and liver disease: The drug can accumulate in kidney disease, and electrolyte shifts can be dangerous in liver disease. Dose adjustment and close monitoring are required.
  • Electrolyte imbalance: This combination can lower potassium and raise uric acid levels, and may trigger gout or worsen blood sugar control.
🔀What it interacts with▾

This medication can interact with several common drugs — always tell your prescriber and pharmacist everything you take.

  • Other blood pressure medicines: Additive lowering of blood pressure; combination may cause blood pressure to drop too much.
  • Verapamil or diltiazem (calcium channel blockers): Can significantly slow the heart rate and worsen heart block — especially dangerous in patients with existing conduction problems.
  • Disopyramide: Can cause severe slow heart rate, heart block, or heart failure when combined with beta-blockers.
  • Amiodarone: Adds to the heart-rate-slowing effect of beta-blockers.
  • Reserpine and other catecholamine-depleting drugs: Can cause very low blood pressure or very slow heart rate.
  • Lithium: Diuretics reduce lithium removal from the body, raising lithium levels to potentially toxic levels.
  • NSAIDs (e.g., indomethacin): May blunt the blood-pressure-lowering effect of this medication.
  • Clonidine: Stopping clonidine while taking a beta-blocker can cause a dangerous rebound spike in blood pressure; careful coordination of stopping is required.
  • Digoxin: Combined use increases the risk of a dangerously slow heart rate.

This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.

📋Before taking it▾
  • Do not take if you have sinus bradycardia (very slow heart rate), significant heart block (greater than first degree), cardiogenic shock, overt heart failure, or no urine output (anuria).
  • Do not take if you are allergic to this product or to sulfonamide-derived drugs.
  • Tell your doctor if you have asthma, COPD, or any lung disease — beta-blockers are generally avoided in bronchospastic conditions.
  • Tell your doctor if you have kidney disease — the atenolol component is cleared by the kidneys and may require dose reduction.
  • Tell your doctor if you have liver disease — fluid and electrolyte imbalances can be especially risky.
  • Tell your doctor if you have diabetes — the drug can hide low blood sugar warning signs and may change your insulin requirements.
  • Tell your doctor if you have a thyroid disorder — abrupt withdrawal can precipitate a thyroid crisis (thyroid storm).
  • Tell your doctor if you have a history of severe allergic reactions — beta-blockers may make those reactions harder to treat with epinephrine.
  • Tell your doctor if you have untreated pheochromocytoma (a type of adrenal tumor) — this drug must not be used in that setting.
  • Pregnancy: Atenolol can cause fetal harm; newborns of mothers taking atenolol may have low blood sugar or slow heart rate. Discuss pregnancy plans or a current pregnancy with your doctor immediately.
  • Breastfeeding: Use with caution; infants may be at risk for low blood sugar and slow heart rate.
🚑If you take too much▾

Taking too much of this medication can cause a very slow heart rate, low blood pressure, difficulty breathing, wheezing, low blood sugar, and in serious cases, heart failure or loss of consciousness. Chlorthalidone overdose may cause nausea, weakness, dizziness, and electrolyte imbalances.

If you suspect an overdose, get emergency medical help immediately. Atenolol can be removed from the bloodstream by hemodialysis (kidney dialysis machine). Treatment is directed by medical professionals based on symptoms.

📡Pharmacodynamics — effects in the body▾

Atenolol slows heart rate and reduces the heart's output of blood, lowering blood pressure both at rest and during exercise. Its beta-blocking effect begins within one hour of a dose, peaks at about 2 to 4 hours, and lasts at least 24 hours — supporting once-daily dosing. Chlorthalidone acts as a diuretic, reducing fluid volume and blood pressure; together, the two drugs produce blood-pressure reductions that are approximately additive.

🔬Pharmacokinetics — how your body processes it▾

About half of an oral atenolol dose is absorbed from the gut; the rest passes out in the stool unchanged. Blood levels peak 2 to 4 hours after taking a tablet. Atenolol is not significantly broken down by the liver — it is cleared mainly by the kidneys, with a half-life of roughly 6 to 7 hours. In patients with significant kidney impairment, atenolol clears more slowly and can accumulate, so dose adjustments are needed when kidney function is substantially reduced.

📦How to store it▾

Store at 20°C to 25°C (68°F to 77°F) . Dispense in well-closed, light-resistant containers.

📄 Written from Atenolol / Chlorthalidone’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Every point is grounded in that labeling — nothing is invented. How we use AI →

🩺 Pharmacist Counseling Corner

Quick, plain-English answers to the questions patients ask most about Atenolol / Chlorthalidone — the kind of thing our pharmacy team would talk through with you at the counter.

What exactly is this medication for? ▾
This tablet combines two medicines — atenolol and chlorthalidone — to lower your blood pressure. Controlling high blood pressure is important because it significantly reduces your chances of having a stroke or heart attack. It's not typically the first blood pressure medicine you'd start on, but it's used once your doctor has figured out that this specific combination is the right fit for you.
Can I just stop taking it if I feel fine or if I'm having side effects? ▾
Please don't stop taking this medication suddenly without talking to your doctor first. Stopping abruptly — especially if you have any underlying heart disease — can cause a rebound effect that may trigger chest pain or even a heart attack. If you're having side effects that bother you, call your doctor and they'll guide you on how to safely taper or switch.
I have diabetes — is there anything I need to watch for with this medication? ▾
Yes, and this is really important. Atenolol can mask one of the main warning signs of low blood sugar — a racing heart. So if your blood sugar drops, you might not feel the usual rapid heartbeat that tips you off. Monitor your blood sugar more closely, and be especially careful if you're fasting, skipping meals, or having any illness that affects your eating. Let your doctor know if you notice any unusual low blood sugar episodes.
What side effects are most common and which ones should make me call my doctor? ▾
The most common things people notice are feeling tired, dizzy, or having cold hands and feet. A slow heart rate is also possible. These are usually mild. You should call your doctor right away if you develop new or worsening shortness of breath or swelling (which could signal heart problems), if you faint, or if you notice an irregular heartbeat, significant muscle weakness, or a skin rash with joint pain. If you're having trouble breathing or wheezing, contact your doctor promptly.
Are there any medicines or supplements I should avoid while taking this? ▾
A few important ones: calcium channel blockers like verapamil or diltiazem can combine with atenolol to slow your heart rate dangerously. Heart rhythm drugs like amiodarone or disopyramide carry similar risks. If you take lithium, this medication can raise lithium levels in your blood to a toxic range. Anti-inflammatory pain relievers like ibuprofen or indomethacin may reduce how well this medication lowers your blood pressure. Always tell every doctor and pharmacist you see that you're on this combination.
Is it safe to take this if I'm pregnant or trying to get pregnant? ▾
This is something to discuss with your doctor right away. Atenolol has been linked to harm to the developing baby, including smaller birth size when taken during the second trimester. If you're pregnant, planning to become pregnant, or are breastfeeding, your doctor needs to weigh the risks carefully and may recommend a different medication. Newborns of mothers taking atenolol may also experience low blood sugar and a slow heart rate, so close monitoring after delivery is important.
Is Atenolol / Chlorthalidone available over the counter? ▾
Atenolol / Chlorthalidone is dispensed by prescription according to its FDA labeling, so it isn't sold over the counter. Your prescriber and pharmacist will determine if it's appropriate for you.
When was Atenolol / Chlorthalidone first available? ▾
Atenolol / Chlorthalidone has been available in the United States since at least 1992, based on FDA approval history (Drugs@FDA) and product marketing records.
Who makes Atenolol / Chlorthalidone? ▾
Atenolol / Chlorthalidone is supplied by 14 manufacturers listed in the FDA NDC Directory, including Actavis Pharma, Inc., Marlex Pharmaceuticals, Inc, Northstar Rx LLC..

💬 Answers drafted from Atenolol / Chlorthalidone’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Grounded in that labeling — nothing is made up. How we use AI →

🧰 Keep exploring

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💊 How Atenolol / Chlorthalidone comes

Atenolol / Chlorthalidone is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.

Tablet

By mouth
Brands Tenoretic
How this form is used
What it may be used for
  • Atenolol And Chlorthalidone tablets are used to treat high blood pressure (hypertension)
  • Tenoretic tablets are used to treat high blood pressure (hypertension)
  • Both products help lower the risk of stroke and heart attack by reducing blood pressure
  • This fixed-dose combination is not for starting blood pressure treatment — it is used when the combination dose matches what a patient already needs
Important instructions
  • Atenolol And Chlorthalidone tablets are taken by mouth once a day; dosage must be individualized by your prescriber
  • Tenoretic tablets are taken by mouth once a day; your doctor will determine the right strength for you
  • Patients with significant kidney impairment may need a reduced dose or less frequent dosing — your prescriber will guide this
  • Do not stop taking this tablet suddenly without your doctor's approval
Available strengths 3 strengths
25 mg / 50 mg 50 mg / 25 mg 100 mg / 25 mg
54 FDA-listed product records ⓘ

📊 Atenolol / Chlorthalidone across the U.S. market

How Atenolol / Chlorthalidone appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.

1
Dose forms ⓘ
14
Manufacturers
2
Brand names
54
FDA-listed product records ⓘ
1992
First marketed ⓘ
Actavis Pharma, Inc.19%
Marlex Pharmaceuticals, Inc11%
Northstar Rx LLC.11%
Remedyrepack Inc.9%
Unichem Pharmaceuticals (USA), Inc.7%
Almatica Pharma LLC7%
Other makers35%

Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.

📈 How widely Atenolol / Chlorthalidone is used

A general measure of how commonly Atenolol / Chlorthalidone is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.

Think of this as a proxy for how widely Atenolol / Chlorthalidone is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.

42,330
Medicaid prescriptions filled (Q1–Q4 2025)
$943,671 gross Medicaid reimbursement (before mandatory rebates — net cost is lower)

How commonly is Atenolol / Chlorthalidone prescribed? Of the 1,596 medications we measure, Atenolol / Chlorthalidone ranks #666 by Medicaid prescriptions — more than 58% of them.

Where Atenolol / Chlorthalidone ranks among the drugs we measure · Q1–Q4 2025 · neighbors ±5
Total prescriptions — #666 of 1,596
#661 Ofatumumab Injection (... 43,282 Rx #662 Albendazole 43,095 Rx #663 Dapsone 42,610 Rx #664 Tezepelumab Injection 42,607 Rx #665 Dornase Alfa 42,474 Rx #666 Atenolol / Chlorthalid... 42,330 Rx #667 Ivabradine 42,299 Rx #668 Prucalopride 42,108 Rx #669 Gadoterate Meglumine 42,002 Rx #670 Linezolid 41,650 Rx #671 Trospium 41,279 Rx

Utilization by Atenolol / Chlorthalidone product

Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.

The 50 mg / 25 mg oral tablet is the most-dispensed Atenolol / Chlorthalidone product — about 70% of these Medicaid prescriptions.

atenolol 50 MG / chlorthalidone 25 MG Oral Tablet Most dispensed

29,475 Medicaid prescriptions (Q1–Q4 2025) 70% of Atenolol / Chlorthalidone prescriptions shown $621,445 gross reimbursement (before rebates) ≈ $21 per prescription (gross)

Summed across the 5 of 21 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 197383

atenolol 100 MG / chlorthalidone 25 MG Oral Tablet

12,855 Medicaid prescriptions (Q1–Q4 2025) 30% of Atenolol / Chlorthalidone prescriptions shown $322,226 gross reimbursement (before rebates) ≈ $25 per prescription (gross)

Summed across the 5 of 20 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 197382

Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.

Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Atenolol / Chlorthalidone, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 10 of 41 listed Atenolol / Chlorthalidone NDCs with Medicaid activity.

🔍 Compare Atenolol / Chlorthalidone products

A representative set of FDA-listed product records for Atenolol / Chlorthalidone — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)

Showing 54 of 54 products — FDA National Drug Code Directory. See every product, package size and price: browse all 54 Atenolol / Chlorthalidone NDCs →

RxNorm Concept Web — From Ingredient to Every Form and Strength

This page starts with one exact multiple-ingredient concept (MIN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). A product with a different ingredient combination belongs on a different page.

Multiple ingredients (MIN) Atenolol / Chlorthalidone RxCUI 151195 1 dose form · 3 strengths

Look up RxCUI 151195 in the RxCUI Atlas →

RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.

🏷️ Sold under these brand names

Tenoretic

🏭 Manufacturers & labelers

Actavis Pharma, Inc. 10 Marlex Pharmaceuticals, Inc 6 Northstar Rx LLC. 6 Remedyrepack Inc. 5 Unichem Pharmaceuticals (USA), Inc. 4 Almatica Pharma LLC 4 Zydus Pharmaceuticals USA Inc. 4 Zydus Lifesciences Limited 4 PD-Rx Pharmaceuticals, Inc. 3 Novitium Pharma LLC 2 ANI Pharmaceuticals, Inc. 2 Upsher-Smith Laboratories, LLC 2 NuCare Pharmaceuticals, Inc. 1 Preferred Pharmaceuticals Inc. 1

RxNorm drug class

Atenolol / Chlorthalidone belongs to the beta-Adrenergic Blocker class.

Pharmacologic class beta-Adrenergic Blocker
Drug family (ATC) Beta blocking agents, selective, Beta blocking agents and calcium channel blockers
How it works Adrenergic beta-Antagonists

Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.

🔬 Where this comes from

Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.

📄
FDA-filed drug labels (SPL) Uses, dosing, warnings & side effects from SPL records retrieved through openFDA; the linked representative set can be verified on DailyMed. ✓ Linked label effective Apr 13, 2026
🏭
Forms, brands & labelersAggregated from ingredient-matched FDA National Drug Code Directory product records for Atenolol / Chlorthalidone.
📈
Real-world reportsThe FDA Adverse Event Reporting System (FAERS), served through openFDA.
🚨
Recalls & shortagesopenFDA drug-enforcement reports and the FDA drug-shortage database.
🧾 Clinical label set — FDA-filed SPL labels retained for Atenolol / Chlorthalidone after exact ingredient or ingredient-combination matching and applicable route/form matching
Clinical labels in scope
11
NDC products indexed
54
Distinct labelers/manufacturers represented
14
Linked representative label ⓘ
Upsher-Smith Laboratories, LLC
Linked label effective
Apr 13, 2026
Composite sections available
17
Linked SPL Set ID
992e66b7-525a-4bf8-bce7-6b29cb120378
Linked SPL Document ID
5719b54f-0775-4524-9904-0663b2ae0995
Open the linked representative label on DailyMed ↗

How we combine label and product data

HelloPharmacist combines public FDA and NLM records; we don’t author the underlying clinical facts. We identified 11 FDA-filed SPL label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. The representative label is the starting point for the displayed reference monograph; the 12 largest stored in-scope SPL records, which may include that representative, are compared section by section, and the longest available version of each section is retained. Forms, routes, brands, labelers, product-listed strengths, and product-record counts are aggregated separately from ingredient-matched FDA NDC Directory records; package records listed above are associated with the linked SPL; and the normalized concept hierarchy comes from NLM RxNorm.

For canonical ingredient pages, bounded product-attributed indication and administration excerpts may be added to the AI evidence, and the generator is instructed to preserve available product, brand, route, and form qualifiers instead of treating one label as universal. Where a section is identified as AI-written, its plain-language text is generated from bounded label evidence. New draft drug pages remain in the admin review queue before first publication. Upsher-Smith Laboratories, LLC is the representative DailyMed label linked for verification and dates; it is not the sole source used for the page.

This is general education, not medical advice — always consult your doctor or pharmacist about your medications and any medical condition. For the exact wording of the linked representative label, view that label on DailyMed; some displayed composite sections may come from other in-scope SPL labels. Learn how we use AI and our data sources & update cadence.