Trental causes changes in your blood that help improve blood flow. This also helps your blood carry oxygen to your tissues and organs.

Trental is used to improve blood flow and reduce certain symptoms of a condition called intermittent claudication (IN-ter-MIT-ent KLOD-ih-KAY-tion). This medicine is not a cure for this condition.

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

You should not use Trental if you have recently had any type of bleeding in your brain or the retina of your eye.

Follow all directions on your prescription label. Do not take Trental in larger or smaller amounts or for longer than recommended.

Trental is usually taken 3 times each day, with meals. Follow your doctor's instructions.

While using Trental, you may need frequent blood tests.

Do not crush, chew, or break an extended-release tablet. Swallow it whole.

It may take up to 4 weeks before your symptoms improve. Keep using the medicine as directed and tell your doctor if your symptoms do not improve after 8 weeks of treatment.

Store at room temperature away from moisture, heat, and light.

You should not use this medicine if you are allergic to Trental, or if you are allergic to caffeine or theophylline (Elixophyllin, Theo-24, Theo-Dur, Slo-Bid, Theochron, Theolair, Uniphyl, and others).

You also should not use Trental if you have recently had any type of bleeding in your brain or the retina of your eyes.

To make sure Trental is safe for you, tell your doctor if you have:

• coronary artery disease (hardened arteries);

• liver or kidney disease;

• heart disease;

• a history of bleeding in your brain or inside your eyes;

• history of heart attack or stroke;

• a stomach or intestinal ulcer;

• if you have recently had surgery;

• if you are also using theophylline; or

• if you use medicine to treat or prevent blod clots.

It is not known whether Trental will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medicine.

Pentoxifylline can pass into breast milk and may harm a nursing baby. You should not breast-feed while you are using pentoxifylline.

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

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

Overdose symptoms may include severe drowsiness, agitation, fever, flushing (warmth, redness, or tingly feeling), fainting, or seizure.

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Stop taking Trental and get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

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

• chest pain;

• pounding heartbeats or fluttering in your chest;

• red or pink urine;

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

• signs of stomach bleeding--bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds.

Common side effects of Trental may include:

• dizziness, headache;

• nausea, vomiting;

• diarrhea, gas; or

• bloating, 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.

If you also take a blood thinner such as warfarin (Coumadin, Jantoven), you may need more frequent "INR" or prothrombin time tests to measure your blood-clotting time.

Other drugs may interact with pentoxifylline, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.