Generic name: Pentoxifylline.

Trental is a blood-viscosity reducer. It reduces blood thickness and increases the ability of red blood cells to modify their shape. 

Quick Facts About Trental


Used to allow blood to flow more freely, thereby relieving painful leg cramps (intermittent claudication). Also used to treat dementia; strokes; circulatory and nerve disorders caused by diabetes; and Raynaud’s syndrome (blood vessel disorder in which exposure to cold causes white fingers and toes). Also prescribed to treat impotence and increase sperm motility in infertile men.

Trental Dosage

Swallow tablet whole; do not break, crush, or chew. Take exactly as prescribed.

  • Usual adult dose: one 400-milligram controlled-release tablet taken 3 times per day with meals. Effects are seen within 2 to 4 weeks; therapy usually does not last for more than 8 weeks. If you experience side effects related to the stomach or central nervous system, doctor will reduce dose, or stop medication if side effects persist.
  • Usual child dose: not generally prescribed for children.
  • Missed dose: take as soon as possible, unless almost time for next dose. In that case, do not take missed dose; go back to regular schedule. Do not double doses.

Trental Side Effects

Overdose symptoms:

Overdose symptoms usually appear within 4 to 5 hours and may last 12 hours. Overdose symptoms: agitation, convulsions, fever, flushing, loss of consciousness, low blood pressure, sleepiness. If you suspect an overdose, immediately seek medical attention.

Side effects: abdominal discomfort allergic reaction (swelling of face, lips, tongue, throat arms, legs, sore throat, fever and chills, difficulty swallowing, chest pain); anxiety; bad taste in the mouth; blind spot in vision; blurred vision; brittle fingernails; chest pain (sometimes crushing); confusion; conjunctivitis (pinkeye); constipation; depression; difficult or labored breathing; dizziness; dry mouth or thirst; earache; excessive salivation; flu-like symptoms; fluid retention; general feeling of bodily discomfort; headache; hives; indigestion; inflammation of the gallbladder; irregular heartbeat; itching; laryngitis; loss of appetite; low blood pressure; nosebleeds; rash; seizures; sore throat or swollen neck glands; stuffy nose; tremor; vomiting, weight change.

No known less common or rare Trental side effects.


Inform your doctor before combining Trental with:

blood thinners such as Coumadin, clot inhibitors such as Persantine, ulcer medications such as Tagamet.

No known food/other substance interactions. 

Special Cautions

If pregnant or planning to become pregnant, inform your doctor immediately. Appears in breast milk; could affect a nursing infant.

No special precautions apply to seniors.

Not generally prescribed for children.

  • Do not take if you have recently had a stroke or bleeding in the retina of the eye, or if sensitive to or allergic to Trental, caffeine, theophylline, or theobromine.
  • Doctor should periodically test your blood if you are taking a blood thinner, have recently had surgery, have a peptic ulcer or other disorder that involves bleeding.
  • Trental is not a substitute for physical therapy or surgery.
  • On occasion, cases of crushing chest pain, low blood pressure, and irregular heartbeat have been experienced by people with heart disease and brain disorders.

Note: provides accurate and independent information prescription pills, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. If you have questions about  dosage, or Trental side effects, please contact your healthcare provider