Dynacirc is a calcium channel blocker that is used to treat hypertension (high blood pressure).

Dynacirc is sometimes used together with a diuretic or "water pill."

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

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

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.

Your blood pressure will need to be checked often. It may take 2 to 4 weeks before your blood pressure improves.

Keep using this medicine 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.

Store at room temperature away from moisture, heat, and light. Keep the bottle tightly closed when not in use.

Use all your blood pressure medications as directed and read all medication guides you receive. Do not change your dose or stop taking your medicine without your doctor's advice.

You should not use Dynacirc if you are allergic to it.

Tell your doctor if you have ever had:

• congestive heart failure;

• liver disease; or

• kidney disease.

Older adults may be more sensitive to the effects of Dynacirc.

It is not known whether Dynacirc will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

You should not breast-feed while using Dynacirc.

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 heartbeats, severe dizziness, and warmth or tingling in your arms and legs.

Avoid getting up too fast from a sitting or lying position, or you may feel dizzy.

Avoid driving or hazardous activity until you know how Dynacirc will affect you. Your reactions could be impaired.

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

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

• a light-headed feeling, like you might pass out;

• pounding heartbeats or fluttering in your chest;

• flushing (warmth, redness, or tingly feeling);

• tiredness; or

• heart problems--swelling, rapid weight gain, feeling short of breath.

Common side effects of Dynacirc may include:

• flushing;

• headache, dizziness;

• swelling;

• fast heartbeats; or

• upset stomach.

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:

• cimetidine (Tagamet);

• fentanyl; or

• rifampin.

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