Side Effects
Dizziness, lightheadedness, tiredness, nausea, and diarrhea may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.
To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.
This product may reduce blood flow to your hands and feet, causing them to feel cold. Smoking may worsen this effect. Dress warmly and avoid tobacco use.
Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
The chlorthalidone in this product may cause dehydration and electrolyte imbalance. Tell your doctor right away if you have any symptoms of dehydration or electrolyte imbalance, including: extreme thirst, very dry mouth, muscle cramps, weakness, fast/irregular heartbeat, confusion.
Tell your doctor right away if you have any serious side effects, including: very slow heartbeat, fainting, trouble breathing, signs of kidney problems (such as change in the amount of urine), toe/joint pain, mental/mood changes (such as depression, mood swings), blue fingers/toes, new or worsening symptoms of heart failure (such as shortness of breath, swelling ankles/feet, unusual tiredness, unusual/sudden weight gain).
Get medical help right away if you have any very serious side effects, including: decrease in vision, eye pain.
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US – Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada – Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
Uses
This medication is used to treat high blood pressure (hypertension). Lowering high blood pressure helps prevent strokes, heart attacks, and kidney problems. This product contains 2 medications: atenolol and chlorthalidone. Atenolol belongs to a class of drugs known as beta blockers. It works by blocking the action of certain natural chemicals in your body, such as epinephrine, on the heart and blood vessels. This effect lowers the heart rate, blood pressure, and strain on the heart. Chlorthalidone is a “water pill” (diuretic) and causes your body to get rid of extra salt and water. This effect may increase the amount of urine you make when you first start the medication. It also helps to relax the blood vessels so that blood can flow more easily.These medications are used together when 1 drug alone is not controlling your blood pressure. Your doctor may direct you to start taking the individual medications first, and then switch you over to this combination product if this is the best dose combination for you.
How to use Atenolol-Chlorthalidone
Take this medication by mouth with or without food as directed by your doctor, usually once daily. If you take this drug too close to bedtime, you may need to wake up to urinate. It is best to take this medication at least 4 hours before your bedtime. Consult your doctor or pharmacist if you have questions about your dosing schedule.
Apple juice and orange juice may prevent your body from fully absorbing atenolol. It is best to avoid drinking apple/orange juice within 4 hours of taking this medication, unless your doctor or pharmacist tells you otherwise.
The dosage is based on your medical condition and response to treatment.
Use this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day.
If you also take certain drugs to lower your cholesterol (bile acid-binding resins such as cholestyramine or colestipol), take this product at least 2 hours before or at least 4 hours after these medications.
It may take several weeks before you get the full benefit of this medication. Keep taking this medication even if you feel well. Most people with high blood pressure do not feel sick.
Tell your doctor if your condition does not improve or if it worsens (for example, your routine blood pressure readings remain high or increase).
Warnings
Do not stop taking this medication without consulting your doctor. Some conditions may become worse when you suddenly stop this drug. Some people who have suddenly stopped taking similar drugs have had chest pain, heart attack, and irregular heartbeat. If your doctor decides you should no longer use this drug, your doctor may direct you to gradually decrease your dose over 1 to 2 weeks.
When gradually stopping this medication, it is recommended that you temporarily limit physical activity to decrease strain on the heart. Get medical help right away if you develop chest pain/tightness/pressure, chest pain spreading to the jaw/neck/arm, unusual sweating, trouble breathing, or fast/irregular heartbeat.
Interactions
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor’s approval.
Some products that may interact with this drug include: dofetilide, fingolimod, lithium.
Some products have ingredients that could raise your heart rate or blood pressure. Tell your pharmacist what products you are using, and ask how to use them safely (especially cough-and-cold products, diet aids, or NSAIDs such as ibuprofen/naproxen).
This medication may interfere with certain lab tests (such as parathyroid, protein-bound iodide), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.
Precautions
Before taking this product, tell your doctor or pharmacist if you are allergic to atenolol or chlorthalidone; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: liver disease, kidney disease, certain types of heart rhythm problems (such as a slow heartbeat, second- or third-degree atrioventricular block), gout, lupus, breathing problems (such as asthma, chronic bronchitis, emphysema), blood circulation problems (such as Raynaud’s disease, peripheral vascular disease), untreated mineral imbalance (such as low potassium), serious allergic reactions including those needing treatment with epinephrine, a certain muscle/nerve disease (myasthenia gravis).
This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).
Too much sweating, diarrhea, or vomiting may cause dehydration and increase your risk of dizziness or lightheadedness. Report prolonged diarrhea or vomiting to your doctor. Be sure to drink enough fluids to prevent dehydration unless your doctor directs you otherwise.
Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
This medication may reduce the potassium levels in your blood. Ask your doctor about adding potassium to your diet. Your doctor may prescribe a potassium supplement.
This product may prevent the fast/pounding heartbeat you would usually feel when your blood sugar level falls too low (hypoglycemia). The risk is higher if you have diabetes, or are vomiting, fasting, or not eating regularly. Other symptoms of low blood sugar level, such as dizziness and sweating, are not affected by this drug.
If you have diabetes, this product may make it harder to control your blood sugar levels. Check your blood sugar levels regularly as directed by your doctor. Tell your doctor right away if you have symptoms of high blood sugar such as increased thirst/urination. Your doctor may need to adjust your diabetes medication, exercise program, or diet.
This medication may make you more sensitive to the sun. Limit your time in the sun. Avoid tanning booths and sunlamps. Use sunscreen and wear protective clothing when outdoors. Tell your doctor right away if you get sunburned or have skin blisters/redness.
Older adults may be more sensitive to the side effects of this drug, especially dizziness.
Tell your doctor if you are pregnant or plan to become pregnant. You should not become pregnant while using this medication. Atenolol may harm an unborn baby. If you become pregnant, talk to your doctor right away about the risks and benefits of this medication.
Atenolol and chlorthalidone pass into breast milk. Atenolol may harm a nursing infant. Consult your doctor before breast-feeding.