Methyldopa and Thiazide Diuretics (Systemic)

Before Using This Medicine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For methyldopa and thiazide diuretics, the following should be considered:

Allergies - Tell your doctor if you have ever had any unusual or allergic reaction to methyldopa, sulfonamides (sulfa drugs), bumetanide, furosemide, indapamide, acetazolamide, dichlorphenamide, methazolamide, or thiazide diuretics (water pills). Also tell your health care professional if you are allergic to any other substances, such as foods, sulfites or other preservatives, or dyes.

Pregnancy - Studies in humans have not shown that methyldopa causes birth defects or other problems. However, when thiazide diuretics are used during pregnancy, they may cause side effects including jaundice, blood problems, and low potassium in the newborn infant. Thiazide diuretics have not been shown to cause birth defects.

Breast-feeding - This medicine passes into breast milk. Thiazide diuretics may decrease the flow of breast milk. Therefore, you should avoid use of thiazide diuretics during the first month of breast-feeding.

Children - Although there is no specific information comparing use of this medicine in children with use in other age groups, it is not expected to cause different side effects or problems in children than it does in adults.

Older adults - Dizziness or light-headedness, drowsiness, or signs of too much potassium loss may be more likely to occur in the elderly, who are more sensitive to the effects of methyldopa and thiazide diuretics.

Other medicines - Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking methyldopa and thiazide diuretics, it is especially important that your health care professional know if you are taking any of the following:

• Digitalis glycosides (heart medicine) - Thiazide diuretics may cause low potassium in the blood, which can lead to symptoms of digitalis toxicity

• Lithium (e.g., Lithane) - Risk of lithium overdose, even at usual doses, may be increased

• Monoamine oxidase (MAO) inhibitor activity (isocarboxazid [e.g., Marplan], phenelzine [e.g., Nardil], procarbazine [e.g., Matulane], selegiline [e.g., Eldepryl], tranylcypromine [e.g., Parnate]) - Taking methyldopa while you are taking or within 2 weeks of taking MAO inhibitors may cause nervousness; headache, severe high blood pressure, and hallucinations have been reported

Other medical problems - The presence of other medical problems may affect the use of methyldopa and thiazide diuretics. Make sure you tell your doctor if you have any other medical problems, especially:

• Angina (chest pain) - Methyldopa may worsen the condition

• Diabetes mellitus (sugar diabetes) - Thiazide diuretics may change the amount of diabetes medicine needed

• Gout (history of) - Thiazide diuretics may increase the amount of uric acid in the blood, which can lead to gout

• High cholesterol - Thiazide diuretics may raise cholesterol levels

• Kidney disease - Effects of methyldopa and thiazide diuretics may be increased because of slower removal from the body. If severe, thiazide diuretics may not work

• Liver disease - Effects of methyldopa may be increased because of slower removal from the body. If thiazide diuretics cause loss of too much water from the body, liver disease can become much worse

• Lupus erythematosus (history of) - Thiazide diuretics may worsen the condition

• Mental depression (history of) - Methyldopa can cause mental depression

• Pancreatitis (inflammation of the pancreas)

• Parkinson's disease - Methyldopa may worsen the condition

• Pheochromocytoma - Methyldopa may interfere with tests for the condition; in addition, there have been reports of increased blood pressure

• If you have taken methyldopa in the past and developed liver problems