Information, Symptoms, Treatments and Resources



This medication is used to treat high blood pressure. Lowering high blood pressure helps prevent strokes, heart attacks, and kidney problems. Chlorthalidone is a "water pill" (diuretic) that causes your body to get rid of extra salt and water. This increases the amount of urine you make. This medication also reduces extra fluid in the body (edema) caused by conditions such as congestive heart failure, liver disease, and kidney disease. Getting rid of extra water helps to reduce fluid in the lungs so that you can breathe easier. It also helps to decrease swelling of the arms, legs, and stomach/abdomen.

Side Effects

Dizziness, lightheadedness, headache, blurred vision, loss of appetite, stomach upset, diarrhea, or constipation may occur as your body adjusts to the medication. You may also experience decreased sexual ability or increased sensitivity to the sun. If any of these effects persist or worsen, notify your doctor or pharmacist promptly. Remember that your doctor has prescribed this medication because he or she 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. This medication may cause a loss of too much body water (dehydration) and salt/minerals. Tell your doctor immediately if you have any of these unlikely but serious symptoms of dehydration or mineral loss: very dry mouth, thirst, muscle cramps, weakness, fast/irregular heartbeat, nausea, vomiting, severe dizziness, unusual drowsiness, unusual decrease in the amount of urine, fainting, confusion, seizures. Tell your doctor immediately if any of these unlikely but serious side effects occur: numbness/tingling of the arms/legs, joint pain (e.g., big toe pain). Tell your doctor immediately if any of these rare but very serious side effects occur: signs of infection (e.g., fever, persistent sore throat), easy bruising/bleeding, stomach/abdominal pain, persistent nausea/vomiting, unusual/persistent tiredness, yellowing eyes/skin, dark urine, unusual change in the amount of urine (not including the normal increase in urine when you first start this drug). A very serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction may include: 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. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.
The information contained in the First DataBank databases is intended to supplement the knowledge of physicians, pharmacists, and other healthcare professionals regarding drug therapy problems and patient counselling information. This information is advisory only and is not intended to replace sound clinical judgment in the delivery of healthcare services. First DataBank disclaims all warranties, whether expressed or implied, including any warranty as to the quality, accuracy, and suitability of this information for any purpose.