Generic Name: Methyclothiazide

  • What is Methyclothiazide?

    Methyclothiazide belongs to a class of medications called diuretics (water pills); it is used alone or in combination with other medications to treat high blood pressure. Methyclothiazide is also used to treat edema (swelling) due to congestive heart failure (a condition in which the heart cannot pump enough blood throughout the body), cirrhosis (scarring of the liver), corticosteroid and estrogen therapy, or kidney problems.

  • What is the most important information I should know about Methyclothiazide?

    Changes in body electrolytes (chemicals that are important for the cells in your body to function, such as sodium and potassium) and body fluids can occur with methyclothiazide. Tell your doctor if you develop dry mouth, thirst, weakness, tiredness, drowsiness, restlessness, muscle pains or cramps, muscle tiredness, dizziness or fainting, low or no urine output, fast heartbeat, or nausea and vomiting.

    Methyclothiazide can cause low blood potassium levels, which can affect your heart and cause irregular heartbeat. Take potassium supplements or increase your intake of potassium-rich foods.

    Methyclothiazide can increase your blood sugar levels. If you have diabetes, check your blood sugar levels regularly. Ask your doctor before you change the dose of your diabetes medicine.

  • Who should not take Methyclothiazide?

    Do not take methyclothiazide if you are allergic to it, any of its ingredients, or sulfonamide medications (such as sulfamethoxazole). In addition, do not take methyclothiazide if you have low or no urine output.

  • What should I tell my doctor before I take the first dose of Methyclothiazide?

    Tell your doctor about all prescription, over-the-counter, and herbal medications you are taking before beginning treatment with methyclothiazide. Also, talk to your doctor about your complete medical history, especially if you have allergies or a history of sulfonamide allergy, asthma, kidney or liver problems, diabetes, gout (severe and painful inflammation of the joints), lupus (disease that affects the immune system), or are pregnant, plan to become pregnant, or are breastfeeding.

  • What is the usual dosage?

    The information below is based on the dosage guidelines your doctor uses. Depending on your condition and medical history, your doctor may prescribe a different regimen. Do not change the dosage or stop taking your medication without your doctor's approval.

    High Blood Pressure

    Adults: The recommended dose is 2.5-5 milligrams (mg) once a day.


    Adults: The recommended dose is 2.5-10 mg once a day.

  • How should I take Methyclothiazide?

    Take methyclothiazide exactly as prescribed by your doctor.

  • What should I avoid while taking Methyclothiazide?

    Do not drink alcohol while you are taking methyclothiazide.

  • What are possible food and drug interactions associated with Methyclothiazide?

    If methyclothiazide is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining methyclothiazide with the following: alcohol, barbiturates (such as phenobarbital), corticosteroids (such as prednisone), diabetes medicines (including insulin), lithium, narcotic painkillers (such as morphine), or other blood pressure medications.

  • What are the possible side effects of Methyclothiazide?

    Side effects cannot be anticipated. If any develop or change in intensity, tell your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking this drug.

    Side effects may include: allergic reactions, constipation, cramping, diarrhea, dizziness, electrolyte imbalance, fainting, fever, headache, jaundice (yellowing of your skin or whites of your eyes), low blood pressure, muscle spasms, nausea, numbness or tingling on your skin, pancreatitis (inflammation of the pancreas), rash, restlessness, stomach irritation, temporary blurred vision, vomiting, weakness

  • Can I receive Methyclothiazide if I am pregnant or breastfeeding?

    The effects of methyclothiazide during pregnancy are unknown. Methyclothiazide can be found in your breast milk if you take it while breastfeeding. Tell your doctor immediately if you are pregnant, plan to become pregnant, or are breastfeeding.

  • What should I do if I miss a dose of Methyclothiazide?

    If you miss a dose of methyclothiazide, take it as soon as you remember. However, if it is almost time for your next dose, skip the one you missed and return to your regular dosing schedule. Do not take two doses at once.

  • How should I store Methyclothiazide?

    Store at room temperature. Protect from light.