Hydrochlorothiazide, Oral

What are other names for this medicine?

Type of medicine: thiazide diuretic

Generic and brand names: hydrochlorothiazide, oral; Hydro-Par; Microzide; Oretic

What is this medicine used for?

This medicine is a diuretic used to treat high blood pressure, fluid retention, and congestive heart failure. Diuretics or "water pills" increase the loss of water and salt through the urine. This medicine may be used for other conditions as determined by your healthcare provider.

What should my healthcare provider know before I take this medicine?

Before taking this medicine, tell your healthcare provider if you have ever had:

• an allergic reaction to any medicine
• diabetes
• electrolyte imbalances such as too much or too little calcium, magnesium, potassium, or sodium in your blood
• gout
• high cholesterol or triglyceride levels in the blood
• liver or kidney disease
• systemic lupus erythematosus (SLE).

Females of childbearing age: Tell your healthcare provider if you are pregnant or plan to become pregnant. It is not known whether this medicine will harm an unborn baby. Do not breast-feed while taking this medicine without your healthcare provider's approval.

How do I take it?

Take this medicine exactly as your healthcare provider prescribes. Take it regularly, even if you feel well.

This medicine increases the frequency of urination. If you take 1 dose per day, take it in the morning. If you take more than 1 dose per day, take the last dose of the day before 6 PM to avoid interrupting your sleep at night.

Taking this medicine with food or milk may lessen the chance the drug will upset your stomach.

If you miss a dose, take it as soon as you remember unless it is almost time for the next scheduled dose. In that case, skip the missed dose and take the next one as directed. Do not take double doses. If you are not sure of what to do if you miss a dose, or if you miss more than one dose, contact your healthcare provider.

What should I watch out for?

This medicine may drive potassium (a vital mineral) from your body. Your healthcare provider may prescribe a potassium-rich diet or a potassium supplement for you to take every day.

You may need to have blood tests regularly to see how this medicine affects you. Keep all appointments for these tests.

This medicine may make you feel tired when you first start taking it. Do not drive or operate machinery unless you are fully alert.

This medicine may make your skin more sensitive to the sun and may cause you to sunburn more easily. While you are taking this medicine, avoid long exposure to the sun. While you are in the sun, wear protective clothing and a sunscreen lotion that is SPF15 or higher until you know how you will react to the sun. Do not use a sunlamp. If you get a severe sunburn, contact your healthcare provider right away.

You may feel dizzy or faint when you get up quickly after sitting or lying down. Getting up slowly may help. Also, drinking alcohol may make it worse. Do not drink alcohol unless your healthcare provider approves.

Diabetics: This medicine may affect your blood sugar level and change the amount of insulin or other diabetes medicines you may need. Talk to your healthcare provider about this.

What are the possible side effects?

Along with its needed effects, your medicine may cause some unwanted side effects. Some side effects may be very serious. Some side effects may go away as your body adjusts to the medicine. Tell your healthcare provider if you have any side effects that continue or get worse.

Life-threatening (Report these to your healthcare provider right away. If you cannot reach your healthcare provider right away, get emergency medical care or call 911 for help): Allergic reaction (hives; itching; rash; trouble breathing; tightness in your chest; swelling of your lips, tongue, and throat).

Serious (report these to your healthcare provider right away): Severe stomach pain, nausea, severe vomiting or diarrhea, rash, muscle cramps, dry mouth, extreme thirst, weakness, black tarry stools, cough or hoarseness, fever, joint pain, lower back or side pain, unusual bleeding or bruising, yellow eyes or skin, irregular heart beat, shortness of breath.

Other: Dizziness, blurred vision, stomach upset, mild diarrhea, sensitivity to sun, loss of appetite, change in sexual desire or ability.

What products might interact with this medicine?

When you take this medicine with other medicines, it can change the way this or any of the other medicines work. Nonprescription medicines, vitamins, natural remedies, and certain foods may also interact. Using these products together might cause harmful side effects. Talk to your healthcare provider if you are taking:

• ACE inhibitors such as enalapril (Vasotec), lisinopril (Prinivil, Zestril), fosinopril (Monopril), captopril (Capoten), quinapril (Accupril), ramipril (Altace), and benazepril (Lotensin)
• alcohol
• angiotensin receptor II blockers such as losartan (Cozaar), irbesartan (Avapro), candesartan (Atacand), and valsartan (Diovan)
• beta blockers such as atenolol (Tenormin), pindolol, metoprolol (Lopressor, Toprol XL), bisoprolol (Zebeta), carvedilol (Coreg), and propranolol (Inderal)
• calcium supplements such as calcium carbonate (Tums), calcium gluconate, calcium lactate, calcium chloride, Cal-Plus, Caltrate 600, Os-cal, Oyster Shell Calcium 500, Citracal, Neo-Calglucon, and Posture
• cholesterol medicines such as cholestyramine (Questran) and colestipol (Colestid)
• clonidine (Catapres)
• corticosteroids such as cortisone (Cortone), betamethasone (Celestone), dexamethasone, fludrocortisone (Florinef), hydrocortisone (Cortef, Hydrocortone, A-HydroCort), methylprednisolone (Medrol), prednisone (Meticorten, Orasone), prednisolone (Delta-Cortef), and triamcinolone (Aristocort, Kenacort)
• cyclosporine (Neoral, Gengraf, Sandimmune)
• digoxin (Lanoxin)
• insulin and medicines taken by mouth for diabetes such as tolbutamide, chlorpropamide (Diabinese), glipizide (Glucotrol), glyburide (PresTab, DiaBeta, Micronase, Glynase), and glimepiride (Amaryl)
• lithium (Lithobid, Eskalith)
• loop diuretics such as furosemide (Lasix), bumetanide (Bumex), ethacrynic acid (Edecrin), and torsemide (Demadex)
• medicines to treat gout such as probenecid (Benemid, Probalan), allopurinol (Aloprim, Zyloprim), and colchicine
• methyldopa (Aldomet)
• nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Motrin, Advil, Nuprin), indomethacin (Indocin), diflunisal (Dolobid), etodolac (Lodine), diclofenac (Voltaren, Cataflam), sulindac (Clinoril), and naproxen (Naprosyn, Aleve).

Keep a list of all your medicines (prescription, nonprescription, supplements, natural remedies, and vitamins) with you. Be sure that you tell all healthcare providers who treat you about all the products you are taking.

How should I store this medicine?

Store this medicine at room temperature. Keep the container tightly closed. Protect it from heat, high humidity, and bright light.

This advisory includes selected information only and may not include all side effects of this medicine or interactions with other medicines. Ask your healthcare provider or pharmacist for more information or if you have any questions.

Ask your pharmacist for the best way to dispose of outdated medicine or medicine you have not used. Do not throw medicine in the trash.

Keep all medicines out of the reach of children.

Do not share medicines with other people.