This medicine may cause you to have an unusual feeling of tiredness when you begin to take it. You may also notice an increase in the amount of urine or in your frequency of urination. After taking the medicine for a while, these effects should lessen. To keep the increase in urine from affecting your sleep:

• If you are to take a single dose a day, take it in the morning after breakfast.
• If you are to take more than one dose a day, take the last dose no later than 6 p.m., unless otherwise directed by your doctor.

However, it is best to plan your dose or doses according to a schedule that will least affect your personal activities and sleep. Ask your health care professional to help you plan the best time to take this medicine.

In addition to the use of the medicine your doctor has prescribed, treatment for your high blood pressure may include weight control and care in the types of foods you eat, especially foods high in sodium. Your doctor will tell you which of these are most important for you. You should check with your doctor before changing your diet.

Many patients who have high blood pressure will not notice any signs of the problem. In fact, many may feel normal. It is very important that you take your medicine exactly as directed and that you keep your appointments with your doctor even if you feel well.

Remember that this medicine will not cure your high blood pressure but it does help control it. Therefore, you must continue to take it as directed if you expect to lower your blood pressure and keep it down. You may have to take high blood pressure medicine for the rest of your life . If high blood pressure is not treated, it can cause serious problems such as heart failure, blood vessel disease, stroke, or kidney disease.

To help you remember to take your medicine, try to get into the habit of taking it at the same time each day.

Dosing

The dose of hydralazine and hydrochlorothiazide combination will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average dose of hydralazine and hydrochlorothiazide combination. If your dose is different, do not change it unless your doctor tells you to do so.

The number of capsules that you take depends on the strength of the medicine.

• For oral dosage forms (capsules):
  • For high blood pressure:
    • Adults 1 capsule two times a day.
    • Children Dose must be determined by your doctor.

Missed dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

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 hydralazine and hydrochlorothiazide, the following should be considered:

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

Pregnancy When hydrochlorothiazide is used during pregnancy, it may cause side effects including jaundice, blood problems, and low potassium in the newborn infant.

Studies with hydralazine have not been done in humans. However, blood problems have been reported in infants of mothers who took hydralazine during pregnancy. In addition, studies in mice have shown that hydralazine causes birth defects (cleft palate, defects in head and face bones); these birth defects may also occur in rabbits, but do not occur in rats.

Breast-feeding Hydrochlorothiazide passes into breast milk. However, neither hydralazine nor hydrochlorothiazide has been reported to cause problems in nursing babies.

Children Although there is no specific information comparing use of this medicine in children with use in other age groups, this medicine is not expected to cause different side effects or problems in children than it does in adults. However, extra caution may be necessary in infants with jaundice, because thiazide diuretics can make this condition worse.

Older adults Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults. Although there is no specific information comparing use of hydralazine and hydrochlorothiazide combination in the elderly with use in other age groups, this medicine is not expected to cause different side effects or problems in older people than it does in younger adults. However, dizziness or lightheadedness or symptoms of too much potassium loss may be more likely to occur in the elderly, who are usually more sensitive to the effects of this medicine. Also, this medicine may reduce tolerance to cold temperatures in elderly patients.

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 hydralazine and hydrochlorothiazide, it is especially important that your health care professional know if you are taking any of the following:

• Cholestyramine or
• Colestipol Use with hydrochlorothiazide may prevent it from working properly; take this combination medicine at least 1 hour before or 4 hours after cholestyramine or colestipol

• Diazoxide (e.g., Proglycem) Effect on blood pressure may be increased

• Digitalis glycosides (heart medicine) Hydrochlorothiazide 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

• Diabetes mellitus (sugar diabetes) Hydrochlorothiazide may change the amount of diabetes medicine needed

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

• Heart or blood vessel disease or
• Stroke (recent) Lowering blood pressure may make problems resulting from these conditions worse

• Kidney disease Hydrochlorothiazide may worsen this condition. Also, the blood pressure lowering effects may be increased because of slower removal of hydralazine from the body

• Liver disease If hydrochlorothiazide causes loss of too much water from the body, liver disease can become much worse

• Lupus erythematosus (history of) Hydrochlorothiazide may worsen the condition