Why is this medication prescribed?

Chlorthalidone is prescribed primarily as a diuretic medication. Here’s why it’s used and how it should be taken:

• Hypertension (High Blood Pressure): Chlorthalidone is commonly prescribed to treat high blood pressure. As a diuretic, chlorthalidone helps the kidneys eliminate excess salt and water from the body, which reduces blood volume and helps lower blood pressure.
• Edema (Fluid Retention): It can also be used to treat edema (fluid retention) associated with various conditions such as congestive heart failure, liver cirrhosis, and kidney disorders.

How should this medicine be used?

Here are the general guidelines for using Chlorthalidone:

• Dosage: The typical starting dose for hypertension is usually 12.5 to 25 mg once daily. The dose can be adjusted by your doctor based on your response to the medication.
• Administration: Chlorthalidone is usually taken orally, with or without food. It is important to take it exactly as prescribed by your doctor.
• Timing: It is often recommended to take chlorthalidone in the morning to prevent frequent urination during the night.
• Follow-up: Your doctor may monitor your blood pressure and electrolyte levels regularly while you are taking chlorthalidone to ensure it is working effectively and not causing any adverse effects.
• Duration: Continue taking chlorthalidone even if you feel well. Stopping suddenly could worsen your condition. If you have concerns about side effects or other issues, discuss them with your doctor before making any changes to your medication regimen.

It’s important to note that chlorthalidone, like any medication, can have side effects and interactions with other drugs. Always follow your doctor’s instructions carefully and inform them of any other medications or supplements you are taking.

Other uses for this medicine

In addition to its primary use as a diuretic for treating hypertension and edema, chlorthalidone may also be prescribed for:

• Nephrolithiasis (Kidney Stones): It can help prevent the formation of calcium-containing kidney stones by increasing urine volume and reducing calcium excretion.
• Diabetes Insipidus: Chlorthalidone may be used to treat nephrogenic diabetes insipidus, a condition where the kidneys are unable to conserve water.
• Osteoporosis: There is some evidence suggesting that thiazide diuretics like chlorthalidone may help prevent bone loss and reduce the risk of osteoporotic fractures in older adults.

What special precautions should I follow?

When taking chlorthalidone, it’s important to be aware of the following precautions:

• Electrolyte Imbalance: Chlorthalidone can cause electrolyte imbalances, particularly low levels of potassium (hypokalemia), sodium (hyponatremia), and magnesium. Your doctor may monitor your electrolyte levels periodically.
• Kidney Function: Since chlorthalidone affects kidney function, it should be used cautiously in patients with impaired kidney function. Your doctor may adjust the dosage accordingly.
• Gout: Chlorthalidone may increase uric acid levels in the blood, which can exacerbate gout or increase the risk of gout attacks in susceptible individuals.
• Diabetes: Chlorthalidone can affect blood sugar levels and may require adjustments in the dosage of antidiabetic medications.
• Pregnancy and Breastfeeding: Chlorthalidone should be used with caution during pregnancy, especially in the second and third trimesters, as it may cause fetal harm. It is not recommended for use while breastfeeding.
• Allergic Reactions: Inform your doctor if you have a history of allergic reactions to sulfa drugs, as chlorthalidone belongs to the thiazide diuretic class, which is chemically related to sulfonamides.
• Interactions: Chlorthalidone can interact with other medications, including nonsteroidal anti-inflammatory drugs (NSAIDs), lithium, corticosteroids, and certain antidiabetic drugs. Always inform your doctor about all medications and supplements you are taking to avoid potential interactions.
• Dehydration: Diuretics like chlorthalidone can cause excessive fluid loss, leading to dehydration. Make sure to drink plenty of fluids unless instructed otherwise by your doctor.

It’s crucial to follow your doctor’s instructions carefully and report any unusual symptoms or side effects while taking chlorthalidone. Regular check-ups and monitoring of blood pressure and electrolytes are typically recommended to ensure the medication is working effectively and safely.

What special dietary instructions should I follow?

• Potassium-Rich Foods: Chlorthalidone can lower potassium levels in the body. Your doctor may recommend consuming potassium-rich foods such as bananas, oranges, potatoes, and spinach to help maintain normal potassium levels. However, avoid potassium supplements unless advised by your doctor.
• Salt Intake: Since chlorthalidone is used to reduce fluid retention and lower blood pressure, it may be beneficial to limit your salt (sodium) intake. This can help enhance the medication’s effectiveness in managing hypertension and edema.

What should I do if I forget a dose?

If you miss a dose of chlorthalidone, take it as soon as you remember. However, if it is almost time for your next scheduled dose, skip the missed dose and continue with your regular dosing schedule. Do not double up on doses to make up for a missed one.

What side effects can this medication cause?

Chlorthalidone, like any medication, can cause side effects. Some common and less serious side effects include:

• Electrolyte Imbalance: This can lead to symptoms such as muscle cramps, weakness, irregular heartbeat, or excessive thirst.
• Dizziness or Lightheadedness: Especially when standing up quickly, due to changes in blood pressure.
• Increased Sensitivity to Sunlight: Making you more prone to sunburn.
• Gastrointestinal Issues: Including nausea, vomiting, diarrhea, or stomach cramps.
• Headache: Mild to moderate headaches are possible.
• Increased Blood Glucose Levels: Particularly in individuals with diabetes.
• Impotence: In some cases, chlorthalidone may affect sexual function.
• Rash or Skin Reactions: Rarely, allergic reactions or skin rash may occur.
• Changes in Blood Uric Acid Levels: This could exacerbate gout in susceptible individuals.
• Low Blood Pressure (Hypotension): Especially if the dosage is too high or if there’s a sudden drop in blood pressure.

Less common but more serious side effects that require immediate medical attention include:

• Severe Allergic Reaction: Symptoms may include rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, or trouble breathing.
• Severe Dehydration: Signs might include extreme thirst, very dry mouth, or decreased urination.
• Kidney Problems: Symptoms can include changes in the amount of urine, painful urination, or blood in the urine.
• Liver Problems: Such as yellowing of the eyes/skin (jaundice) or persistent nausea/vomiting.
• Pancreatitis: Symptoms include severe abdominal/stomach pain, persistent nausea/vomiting, or loss of appetite.

If you experience any serious side effects or any unusual symptoms while taking chlorthalidone, it’s important to seek immediate medical attention. Always discuss any concerns or side effects with your healthcare provider to ensure proper management and adjustment of your treatment plan if needed.

What should I know about storage and disposal of this medication?

Storage and Disposal of Chlorthalidone:

• Storage: Store chlorthalidone tablets at room temperature, away from light and moisture. Avoid storing it in the bathroom. Keep it out of reach of children and pets.
• Disposal: Dispose of unused or expired chlorthalidone tablets safely. You can ask your pharmacist about the best way to dispose of medications that are no longer needed or have expired.

In case of emergency/overdose

If you suspect an overdose of chlorthalidone, seek immediate medical attention or contact a poison control center (such as 1-800-222-1222 in the United States). Overdose symptoms may include:

• Excessive dehydration (extreme thirst, very dry mouth)
• Severe dizziness or fainting
• Muscle cramps or weakness
• Irregular heartbeat
• Confusion or severe drowsiness
• Seizures

What other information should I know?

• Regular Monitoring: Your doctor may periodically check your blood pressure, kidney function, and electrolyte levels (potassium, sodium, etc.) while you are taking chlorthalidone.
• Avoid Alcohol: Alcohol consumption may enhance certain side effects of chlorthalidone such as dizziness or lightheadedness. It’s generally advisable to limit alcohol intake or avoid it altogether while taking this medication.
• Medical and Dental Procedures: Inform healthcare providers, including dentists, that you are taking chlorthalidone before undergoing any surgical or dental procedures. It may be necessary to temporarily adjust your medication regimen.
• Pregnancy and Breastfeeding: If you are pregnant or planning to become pregnant, discuss the risks and benefits of using chlorthalidone with your doctor. It is generally not recommended during pregnancy, especially in the second and third trimesters. Avoid breastfeeding while taking chlorthalidone, as it may pass into breast milk and harm the nursing infant.
• Driving and Machinery: Chlorthalidone may cause dizziness or drowsiness. Be cautious when driving or operating machinery until you know how this medication affects you.
• Routine Follow-up: Keep all scheduled appointments with your healthcare provider to monitor your response to chlorthalidone and to detect any potential side effects early.

Always follow your doctor’s instructions and advice regarding the use of chlorthalidone and report any concerns or unusual symptoms promptly. This medication can be effective in managing certain conditions but requires careful monitoring and adherence to safety precautions.