Chlorthalidone, Oral klor-THAL-ih-dohn

What are other names for this medicine?

Type of medicine: thiazide diuretic

Generic and brand names: chlorthalidone, oral; Thalitone

What is this medicine used for?

This medicine is a diuretic used to treat high blood pressure, fluid retention, and heart failure. It may be used alone or along with other medicines. Diuretics or "water pills" increase the loss of water and salt through the urine. This medicine may be used for other conditions as determined by your healthcare provider.

What should my healthcare provider know before I take this medicine?

Before taking this medicine, tell your healthcare provider if you have ever had:

• an allergic reaction to any medicine
• asthma
• diabetes
• glaucoma
• gout
• high cholesterol or triglyceride levels in the blood
• imbalances such as too much or too little calcium, magnesium, potassium, or sodium in your blood
• liver or kidney disease
• systemic lupus erythematosus (SLE)

Females of childbearing age: Tell your healthcare provider if you are pregnant or plan to become pregnant. Do not breast-feed while taking this medicine without your health care provider’s approval.

How do I take it?

Check the label on the medicine for directions about your specific dose. Take this medicine exactly as your healthcare provider prescribes. Take it regularly, even if you feel well. Do not stop taking this medicine without your healthcare provider's approval.

This medicine increases the frequency of urination. If you take 1 dose per day, take it in the morning. If you take more than 1 dose per day, take the last dose of the day before 6 PM to avoid interrupting your sleep at night.

Taking this medicine with food or milk may lessen the chance the drug will upset your stomach.

What if I miss a dose?

If you miss a dose, take it as soon as you remember unless it is almost time for the next scheduled dose. In that case, skip the missed dose and take the next one as directed. Do not take double doses. If you are not sure of what to do if you miss a dose, or if you miss more than one dose, contact your healthcare provider.

What if I overdose?

If you or anyone else has intentionally taken too much of this medicine, call 911 or go to the emergency room right away. If you pass out, have seizures, weakness or confusion, or have trouble breathing, call 911. If you think that you or anyone else may have taken too much of this medicine, call the poison control center. Do this even if there are no signs of discomfort or poisoning. The poison control center number is 800-222-1222.

Symptoms of an acute overdose may include: nausea, weakness, dizziness, lightheadedness, drowsiness, fainting, dry mouth, increased urination, vomiting, diarrhea, confusion, irregular heartbeat.

What should I watch out for?

This medicine may drive potassium (a vital mineral) from your body. Your healthcare provider may prescribe a potassium-rich diet or a potassium supplement for you to take every day.

This medicine may increase the risk of dehydration. Contact your healthcare provider if you develop severe vomiting or diarrhea while you are taking this medicine. Be careful when exercising, especially in hot weather.

You may need to have blood tests regularly to see how this medicine affects you. Keep all appointments for these tests.

This medicine may cause eye problems that could lead to vision loss. Contact your healthcare provider right away if you have eye pain or a decrease in vision.

This medicine may make you feel tired or dizzy when you first start taking it. Do not drive or operate machinery unless you are fully alert.

This medicine may make your skin more sensitive to the sun and may cause you to sunburn more easily. While you are taking this medicine, avoid long exposure to the sun. While you are in the sun, wear protective clothing and a sunscreen lotion that is SPF15 or higher until you know how you will react to the sun. Do not use a sunlamp. If you get a severe sunburn, contact your healthcare provider right away.

You may feel dizzy or faint when you get up quickly after sitting or lying down. Getting up slowly may help. Also, drinking alcohol may make it worse. Do not drink alcohol unless your healthcare provider approves.

If you need emergency care, surgery, or dental work, tell the healthcare provider or dentist you are taking this medicine.

Diabetics: This medicine may affect your blood sugar level and change the amount of insulin or other diabetes medicines you may need. Talk to your healthcare provider about this.

What are the possible side effects?

Along with its needed effects, your medicine may cause some unwanted side effects. Some side effects may be very serious. Some side effects may go away as your body adjusts to the medicine. Tell your healthcare provider if you have any side effects that continue or get worse.

Life-threatening (Report these to your healthcare provider right away. If you cannot reach your healthcare provider right away, get emergency medical care or call 911 for help): Allergic reaction (hives; itching; rash; trouble breathing; tightness in your chest; swelling of your lips, tongue, and throat).

Serious (report these to your healthcare provider right away): Severe stomach pain, nausea, severe vomiting or diarrhea; severe skin rash, redness, blisters or peeling; eye pain, decrease or changes in vision, muscle pains or cramps, dry mouth, extreme thirst, weakness, black tarry stools, cough or hoarseness, fever, joint pain, lower back or side pain, unusual bleeding or bruising, yellow eyes or skin, irregular or fast heartbeat, shortness of breath, decreased or trouble urinating, severe dizziness or fainting, unusual restlessness or confusion, seizures.

Other: Dizziness, blurred vision, stomach upset, mild diarrhea, sensitivity to sun, loss of appetite, change in sexual desire or ability.

What products might interact with this medicine?

When you take this medicine with other medicines, it can change the way this or any of the other medicines work. Nonprescription medicines, vitamins, natural remedies, and certain foods may also interact. Using these products together might cause harmful side effects. Talk to your healthcare provider if you are taking:

• ACE inhibitors such as benazepril (Lotensin), captopril, enalapril (Vasotec), lisinopril (Prinivil, Zestril), fosinopril, quinapril (Accupril), and ramipril (Altace)
• alcohol
• alpha blockers such as doxazosin (Cardura) and prazosin (Minipress)
• angiotensin receptor II blockers such as candesartan (Atacand), irbesartan (Avapro), losartan (Cozaar), olmesartan (Benicar), telmisartan (Micardis), and valsartan (Diovan)
• aspirin and other salicylates
• barbiturates such as butabarbital (Butisol), pentobarbital (Nembutal), phenobarbital, and secobarbital (Seconal)
• beta blockers such as atenolol (Tenormin), bisoprolol (Zebeta), carvedilol (Coreg), labetalol (Trandate), metoprolol (Lopressor, Toprol XL), pindolol, and propranolol (Inderal)
• calcium channel blockers such as diltiazem (Cardizem, Tiazac), felodipine, isradipine (DynaCirc CR), nicardipine (Cardene), nifedipine (Adalat CC, Procardia), and verapamil (Calan, Covera-HS, Isoptin SR, Verelan)
• calcium supplements such as calcium carbonate (Tums), calcium gluconate, calcium lactate, calcium chloride, Cal-Plus, Caltrate 600, Os-cal, Oyster Shell Calcium 500, Citracal, Neo-Calglucon, and Posture
• carbamazepine (Tegretol, Carbatrol)
• carbonic anhydrase inhibitors such as acetazolamide (Diamox) and methazolamide (Neptazane)
• cholesterol medicines such as cholestyramine (Questran) and colestipol (Colestid)
• clonidine (Catapres)
• corticosteroids such as betamethasone (Celestone), cortisone, dexamethasone, fludrocortisone (Florinef), hydrocortisone (Cortef), methylprednisolone (Medrol), prednisone, prednisolone, and triamcinolone (Aristospan, Kenalog)
• heart medicines such as amiodarone (Cordarone, Pacerone), digoxin (Lanoxin), and dofetilide (Tikosyn)
• insulin and medicines taken by mouth for diabetes such as chlorpropamide, glimepiride (Amaryl), glipizide (Glucotrol), glyburide (DiaBeta, Glynase PresTab), and tolbutamide
• lithium (Lithobid)
• medicines to treat gout such as allopurinol (Aloprim, Zyloprim), colchicine, and probenecid
• methyldopa
• narcotic pain medicines such as codeine, hydrocodone (Lortab, Norco, Vicodin), morphine, oxycodone (OxyContin), and oxycodone/acetaminophen (Percocet, Tylox)
• natural remedies such as dong quai, ginseng, hawthorn, horse chestnut, natural licorice, St. John’s wort, and yohimbe
• nonsteroidal anti-inflammatory drugs (NSAIDs) such as celecoxib (Celebrex), diclofenac (Voltaren, Cataflam), diflunisal, etodolac, ibuprofen (Motrin, Advil), indomethacin (Indocin), ketoprofen, ketorolac (Toradol), nabumetone (Relafen), naproxen (Naprosyn, Aleve), oxaprozin (Daypro), piroxicam (Feldene), and sulindac (Clinoril)
• other diuretics such as amiloride, bumetanide, ethacrynic acid (Edecrin), furosemide (Lasix), spironolactone (Aldactone), torsemide (Demadex), and triamterene (Dyrenium)

If you are not sure if your medicines might interact, ask your pharmacist or healthcare provider. Keep a list of all your medicines with you. List all the prescription medicines, nonprescription medicines, supplements, natural remedies, and vitamins that you take. Be sure that you tell all healthcare providers who treat you about all the products you are taking.

How should I store this medicine?

Store this medicine at room temperature. Keep the container tightly closed. Protect it from heat, high humidity, and bright light.

This advisory includes selected information only and may not include all side effects of this medicine or interactions with other medicines. Ask your healthcare provider or pharmacist for more information or if you have any questions.

Ask your pharmacist for the best way to dispose of outdated medicine or medicine you have not used. Do not throw medicine in the trash.

Keep all medicines out of the reach of children.

Do not share medicines with other people.