HYDROCHLOROTHIAZIDE (hye droe klor oh THYE a zide) treats high blood pressure. It may also be used to reduce swelling related to heart, kidney, or liver disease. It helps your kidneys remove more fluid and salt from your blood through the urine. It belongs to a group of medications called diuretics.
What should I tell my care team before I take this medication?
They need to know if you have any of these conditions:
An unusual or allergic reaction to hydrochlorothiazide, sulfa drugs, other medications, foods, dyes, or preservatives
Pregnant or trying to get pregnant
How should I use this medication?
Take this medication by mouth. Take it as directed on the prescription label at the same time every day. You can take it with or without food. If it upsets your stomach, take it with food. Keep taking it unless your care team tells you to stop.
Talk to your care team about the use of this medication in children. While it may be prescribed for children as young as newborns for selected conditions, precautions do apply.
What if I miss a dose?
If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.
What may interact with this medication?
Medications for blood pressure
Medications for diabetes
Medications that relax muscles for surgery
Steroid medications like prednisone or cortisone
What side effects may I notice from receiving this medication?
Side effects that you should report to your care team as soon as possible:
Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
Dehydration—increased thirst, dry mouth, feeling faint or lightheaded, headache, dark yellow or brown urine
Gout—severe pain, redness, warmth, or swelling in joints, such as the big toe
Kidney injury—decrease in the amount of urine, swelling of the ankles, hands, or feet
Low blood pressure—dizziness, feeling faint or lightheaded, blurry vision
Low potassium level—muscle pain or cramps, unusual weakness, fatigue, fast or irregular heartbeat, constipation
Sudden eye pain or change in vision such as blurred vision, seeing halos around lights, vision loss
Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):
Change in sex drive or performance
What should I watch for while using this medication?
Visit your health care provider for regular check-ups. Check your blood pressure as directed. Ask your health care provider what your blood pressure should be. Also, find out when you should contact him or her.
Do not treat yourself for coughs, colds, or pain while you are using this medication without asking your health care provider for advice. Some medications may increase your blood pressure.
You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medication affects you. Do not stand or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells. Alcohol can make you more drowsy and dizzy. Avoid alcoholic drinks.
Talk to your health care professional about your risk of skin cancer. You may be more at risk for skin cancer if you take this medication.
This medication can make you more sensitive to the sun. Keep out of the sun. If you cannot avoid being in the sun, wear protective clothing and use sunscreen. Do not use sun lamps or tanning beds/booths.
You may need to be on a special diet while taking this medication. Ask your health care provider. Also, find out how many glasses of fluids you need to drink each day.
Check with your health care provider if you get an attack of severe diarrhea, nausea and vomiting, or if you sweat a lot. The loss of too much body fluid can make it dangerous for you to take this medication.
This medication may increase blood sugar. Ask your healthcare provider if changes in diet or medications are needed if you have diabetes.
Where should I keep my medication?
Keep out of the reach of children and pets.
Store at room temperature between 20 and 25 degrees C (68 and 77 degrees F). Protect from light and moisture. Keep the container tightly closed. Do not freeze. Get rid of any unused medication after the expiration date.
To get rid of medications that are no longer needed or have expired:
Take the medication to a medication take-back program. Check with your pharmacy or law enforcement to find a location.
If you cannot return the medication, check the label or package insert to see if the medication should be thrown out in the garbage or flushed down the toilet. If you are not sure, ask your care team. If it is safe to put in the trash, empty the medication out of the container. Mix the medication with cat litter, dirt, coffee grounds, or other unwanted substance. Seal the mixture in a bag or container. Put it in the trash.
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.
This information is educational only and should not be construed as specific instructions for individual patients nor as a substitute for medical advice, diagnosis or treatment. Talk to your health care provider or pharmacist about the information and instructions. K Health assumes no liability for any use or reliance on this information.