Hydrochlorothiazide is a thiazide diuretic (water pill). Metoprolol is a beta-blocker.

Lopressor HCT is a combination medicine used to treat high blood pressure (hypertension).

Lopressor HCT may also be used for purposes not listed in this medication guide.

You should not use Lopressor HCT if you have a serious heart condition such as "sick sinus syndrome" or "AV block" (unless you have a pacemaker), slow heartbeats that have caused you to faint, or if your heart cannot pump blood properly.

You should not use Lopressor HCT if you are unable to urinate.

Do not stop using this medicine suddenly, even if you feel fine. Stopping suddenly may cause serious or life-threatening heart problems. Follow your doctor's instructions about tapering your dose.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

You may take Lopressor HCT with (or immediately after food) or without food.

Some things can cause your blood pressure to get too low. This includes vomiting, diarrhea, or heavy sweating. Call your doctor if you are sick with vomiting or diarrhea.

Your blood pressure will need to be checked often. You may also need frequent blood tests.

If you are diabetic, check your blood sugar carefully. Taking Lopressor HCT can make it harder for you to tell when you have low blood sugar. Do not change your medication dose or schedule without your doctor's advice.

If you need surgery, tell the surgeon ahead of time that you are using Lopressor HCT.

Keep using Lopressor HCT as directed, even if you feel well. High blood pressure often has no symptoms. You may need to use blood pressure medicine for the rest of your life.

Do not stop using Lopressor HCT suddenly, even if you feel fine. Stopping suddenly may cause serious or life-threatening heart problems. Follow your doctor's instructions about tapering your dose.

Store at room temperature away from moisture and heat.

You should not use this medicine if you are allergic to hydrochlorothiazide or metoprolol, or if you have:

• a serious heart condition such as "sick sinus syndrome" or "AV block" (unless you have a pacemaker), or if your heart cannot pump blood properly;

• slow heartbeats that have caused you to faint;

• severe or uncontrolled heart failure;

• an allergy to sulfa drugs; or

• if you are unable to urinate.

Tell your doctor if you have ever had:

• congestive heart failure;

• slow heartbeats;

• blood circulation problems;

• asthma or other breathing disorder;

• peripheral vascular disease such as Raynaud's syndrome;

• diabetes;

• a thyroid disorder;

• kidney disease (or if you are on dialysis);

• pheochromocytoma (tumor of the adrenal gland);

• glaucoma;

• lupus;

• gout; or

• high cholesterol or triglycerides.

Tell your doctor if you are pregnant or breastfeeding.

Lopressor HCT is not approved for use by anyone younger than 18 years old.

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include fast or slow heart rate, trouble breathing, or fainting.

Avoid driving or hazardous activity until you know how Lopressor HCT will affect you. Your reactions could be impaired. Avoid getting up too fast from a sitting or lying position, or you may feel dizzy.

Drinking alcohol with this medicine can cause side effects.

Avoid becoming overheated or dehydrated during exercise and in hot weather. Follow your doctor's instructions about the type and amount of liquids you should drink. In some cases, drinking too much liquid can be as unsafe as not drinking enough.

Hydrochlorothiazide may increase your risk of skin cancer. Avoid sunlight or tanning beds. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors. Your doctor may want you to have skin examinations on a regular basis.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Lopressor HCT may cause serious side effects. Call your doctor at once if you have:

• bronchospasm (wheezing, chest tightness, trouble breathing);

• slow heart rate, weak pulse, fainting, slow breathing (breathing may stop);

• blurred vision, tunnel vision, eye pain, or seeing halos around lights;

• low potassium level--leg cramps, constipation, irregular heartbeats, fluttering in your chest, increased thirst or urination, numbness or tingling, muscle weakness or limp feeling; or

• low sodium level --headache, confusion, slurred speech, severe weakness, vomiting, loss of coordination, feeling unsteady.

Common side effects of Lopressor HCT may include:

• tired feeling; or

• stuffy nose, sore throat.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Tell your doctor about all your other medicines, especially:

• cholestyramine, colestipol;

• clonidine;

• digoxin;

• diltiazem, verapamil;

• epinephrine (Epi-Pen);

• lithium;

• an MAO inhibitor--isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, tranylcypromine, and others; or

• an NSAID (nonsteroidal anti-inflammatory drug)--aspirin, ibuprofen (Advil, Motrin), naproxen (Aleve), celecoxib, diclofenac, indomethacin, meloxicam, and others.

This list is not complete. Other drugs may affect Lopressor HCT, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.