Managing Chlorthalidone and Potassium Levels (Plus 4 More Pharmacist-Backed Tips)
Key takeaways:
Chlorthalidone (Thalitone) is a water pill that treats high blood pressure and fluid retention. It can cause low potassium levels, so it’s a good idea to include potassium-rich foods in your diet while you’re taking it.
It’s best to take chlorthalidone in the morning with food to reduce side effects. Your healthcare team may recommend a specific diet to help manage your symptoms. Be sure to choose foods that fall within your plan to help chlorthalidone work its best.
Chlorthalidone can make your skin more sensitive to sunlight. Use sunscreen and wear sun-protective clothing when you’re outside, and avoid tanning beds while you’re taking it. Let your healthcare team know if you have a sulfa allergy. This can also cause a skin reaction to chlorthalidone in rare cases.
Thalitone and chlorthalidone aren’t interchangeable. Thalitone is only available as a brand-name medication. But chlorthalidone is available as a lower-cost generic. GoodRx can help make your prescription for either medication more affordable.
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Table of contents
Chlorthalidone is a diuretic (“water pill”) that treats high blood pressure and excess fluid in the body (edema). Chlorthalidone is also the active ingredient in Thalitone, a brand-name medication that treats the same conditions.
Generic chlorthalidone and Thalitone aren’t interchangeable, and they have different recommended dosages. But they work the same way in the body. Some general tips can help you get the most from your chlorthalidone-based medication.
Here, we’ll discuss five tips for taking chlorthalidone, including how to manage chlorthalidone’s effect on potassium levels. We’ll refer to chlorthalidone throughout this article, but these tips also apply if you’re taking Thalitone.
1. You may need more potassium while you’re taking chlorthalidone
Chlorthalidone works by helping your kidneys get rid of extra water and sodium (salt) from your body. This helps treat edema and lowers your blood pressure. But it can also affect the balance of your other electrolytes, including potassium. As a result, your potassium levels can drop while you’re taking chlorthalidone. This is more likely with higher doses of chlorthalidone or if you’re also taking another diuretic with this side effect.
Low potassium levels (hypokalemia) may not cause symptoms for some people. But if your levels drop too low, it can cause muscle cramps, constipation, and weakness. It can also make you feel dizzy or lightheaded. Your prescriber will likely check your potassium levels while you’re taking chlorthalidone. But be sure to let them know if these symptoms appear.
Your prescriber may recommend eating more potassium-rich foods while you’re taking chlorthalidone. Examples include avocados, squash, and potatoes. If your potassium levels drop too low, they may prescribe a potassium supplement, such as potassium chloride (Klor-Con), to keep your levels up. You may also need a magnesium supplement, as low magnesium can contribute to low potassium levels. But you shouldn’t take any supplements on your own unless your prescriber recommends them.
2. It’s best to take chlorthalidone in the morning
As with other water pills, chlorthalidone can make you pee more often than usual. So it’s best to take it in the morning. Taking chlorthalidone later in the day can lead to bathroom trips at night when you’d rather be sleeping.
Keep in mind that your kidneys need plenty of fluid to work properly. Be sure to stay hydrated — don’t avoid fluids in an effort to pee less often. If your bathroom trips are frequent enough to disrupt your daily life, let your prescriber know. They may want to change your dose or medication to help manage it.
3. It’s best to take chlorthalidone with food
Chlorthalidone can cause nausea and an upset stomach for some people. Taking it with food can help lower the chance of these side effects. Scheduling your daily dose for after breakfast can help you remember to take it in the morning, too.
How do chlorthalidone and hydrochlorothiazide compare? Learn how these two thiazide diuretics compare and which is preferred for high blood pressure.
What are chlorthalidone’s side effects? Here’s what side effects to keep an eye out for while you’re taking chlorthalidone and when to contact a healthcare professional.
What does high blood pressure feel like? Read these first-hand accounts to get a sense of what high blood pressure feels like and tips to successfully manage it.
Keep in mind that if you have high blood pressure or edema, your prescriber may suggest dietary changes to improve your health. One example is the DASH diet, which stands for Dietary Approaches to Stop Hypertension. A general low-sodium diet is another option. These changes may seem tricky at first. But paying attention to what you’re eating can help chlorthalidone work better to manage your symptoms.
4. You’ll need extra protection from the sun while taking chlorthalidone
Chlorthalidone can make your skin more sensitive to the sun. Reactions can vary from person to person. You may sunburn easier than usual or experience an itchy, blistering rash. Sun-related skin reactions can also raise your risk of skin cancer.
The following tips can help protect your skin while you’re taking chlorthalidone:
Avoid direct sunlight. When you’re outside, stay in the shade as much as possible. Or make your own shady spot with an umbrella or folding chair with a shade cover. Avoid tanning beds.
Use sunscreen. Apply a broad-spectrum sunscreen with SPF 30 or higher. Choose a product that protects against both UVA and UVB rays, and reapply it every few hours.
Wear protective clothing. Opt for long sleeves and a wide-brimmed hat. And don’t forget your sunglasses. Consider looking for clothing labeled as UV protective.
If you develop a severe sunburn or skin rash while taking chlorthalidone, let your prescriber know.
5. Let your prescriber know if you have a sulfa allergy before taking chlorthalidone
If you have a sulfa allergy, your immune system reacts to a portion of a medication known as a sulfonamide. In most cases, these reactions happen with sulfa antibiotics, such as Bactrim (sulfamethoxazole / trimethoprim).
Other medications, including chlorthalidone, also contain sulfonamides. According to research, it’s unlikely that you’ll have a reaction to chlorthalidone if you have a sulfa allergy. But it’s still a possibility. So be sure to let your healthcare team know about your allergies before you start taking chlorthalidone. They may prefer a different medication for you, or they may just have you keep a close eye out for any symptoms of an allergic reaction.
If you develop hives; have trouble breathing; or notice swelling of your tongue, mouth, or throat after taking chlorthalidone, call 911 or seek emergency care right away.
Tips for saving on chlorthalidone
Thalitone is only available as a brand-name medication. GoodRx can help you save up to 20% off the cost of a month’s supply of Thalitone with a free discount.
Chlorthalidone is available as a lower-cost generic. GoodRx can help you save over 60% off the average retail price. Generic chlorthalidone’s price is as low as $9.00 at certain pharmacies with a free discount from GoodRx.
The bottom line
Chlorthalidone is a diuretic (“water pill”) that treats high blood pressure and excess fluid (edema). Thalitone is a brand-name version of chlorthalidone. The two medications aren’t interchangeable, but the same tips apply for both.
Taking chlorthalidone in the morning can help reduce nighttime trips to the bathroom. Chlorthalidone can lower your potassium levels, so adding potassium-rich foods to your diet is a good idea while you’re taking it. Taking it with food can also help reduce nausea, so planning your daily dose for after breakfast works well for most people. Just be sure to choose foods that fall within the dietary guidelines that your healthcare team recommends.
Chlorthalidone can make your skin more sensitive to the sun. It’s important to wear sunscreen and protective clothing when you’re outside. If you’re allergic to sulfa drugs, there’s a chance you may react to chlorthalidone. Be sure to let your healthcare team know about your allergies before you start taking it.
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References
Casper Pharma LLC. (2019). Thalitone - chlorthalidone tablet [package insert].
Chou-Long, H., et al. (2007). Mechanism of hypokalemia in magnesium deficiency. Journal of the American Society of Nephrology.
Giles, A., et al. (2019). Sulfonamide allergies. Pharmacy.
Kerndt, C. C., et al. (2024). Chlorthalidone. StatPearls.
Lozzi, F., et al. (2020). Latest evidence regarding the effects of photosensitive drugs on the skin: Pathogenetic mechanisms and clinical manifestations. Pharmaceutics.
National Heart, Lung, and Blood Institute. (2021). DASH eating plan. National Institutes of Health.
National Kidney Foundation. (2024). Healthy hydration and your kidneys.
Oakley, A. M., et al. (2023). Photosensitivity. StatPearls.
Sica, D. A., et al. (2011). Thiazide and loop diuretics. The Journal of Clinical Hypertension.
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