The table indicates that in the tablet studies few patients discontinued because of adverse effects.

TRENTAL has been marketed in Europe and elsewhere since 1972. In addition to the above symptoms, the following have been reported spontaneously since marketing or occurred in other clinical trials with an incidence of less than 1%; the causal relationship was uncertain:

A few rare events have been reported spontaneously worldwide since marketing in 1972. Although they occurred under circumstances in which a causal relationship with pentoxifylline could not be established, they are listed to serve as information for physicians. Cardiovascular — angina, arrhythmia, tachycardia, anaphylactoid reactions. Digestive — hepatitis, jaundice, increased liver enzymes; and Hemic and Lymphatic — decreased serum fibrinogen, pancytopenia, aplastic anemia, leukemia, purpura, thrombocytopenia.

INCIDENCE (%) OF SIDE EFFECTS  Extended-Release Tablets Immediate-Release Capsules
 Commercially Available Used only for Controlled Clinical Trials
 TRENTAL Placebo TRENTAL Placebo
(Numbers of Patients at Risk) (321) (128) (177) (138)
Discontinued for Side Effect 3.1 0 9.6 7.2
CARDIOVASCULAR SYSTEM     
Angina/Chest Pain 0.3 - 1.1 2.2
Arrhythmia/Palpitation - - 1.7 0.7
Flushing - - 2.3 0.7
DIGESTIVE SYSTEM     
Abdominal Discomfort - - 4.0 1.4
Belching/Flatus/Bloating 0.6 - 9.0 3.6
Diarrhea - - 3.4 2.9
Dyspepsia 2.8 4.7 9.6 2.9
Nausea 2.2 0.8 28.8 8.7
Vomiting 1.2 - 4.5 0.7
NERVOUS SYSTEM     
Agitation/Nervousness - - 1.7 0.7
Dizziness 1.9 3.1 11.9 4.3
Drowsiness - - 1.1 5.8
Headache 1.2 1.6 6.2 5.8
Insomnia - - 2.3 2.2
Tremor 0.3 0.8 - -
Blurred Vision - - 2.3 1.4

Overdosage with TRENTAL has been reported in pediatric patients and adults. Symptoms appear to be dose related. A report from a poison control center on 44 patients taking overdoses of enteric-coated pentoxifylline tablets noted that symptoms usually occurred 4–5 hours after ingestion and lasted about 12 hours. The highest amount ingested was 80 mg/kg; flushing, hypotension, convulsions, somnolence, loss of consciousness, fever, and agitation occurred. All patients recovered. In addition to symptomatic treatment and gastric lavage, special attention must be given to supporting respiration, maintaining systemic blood pressure, and controlling convulsions. Activated charcoal has been used to absorb pentoxifylline in patients who have overdosed.

The usual dosage of TRENTAL in extended-release tablet form is one tablet (400 mg) three times a day with meals.

While the effect of TRENTAL may be seen within 2 to 4 weeks, it is recommended that treatment be continued for at least 8 weeks. Efficacy has been demonstrated in double-blind clinical studies of 6 months duration.

Digestive and central nervous system side effects are dose related. If patients develop these effects it is recommended that the dosage be lowered to one tablet twice a day (800 mg/day). If side effects persist at this lower dosage, the administration of TRENTAL should be discontinued.

TRENTAL (pentoxifylline) is available for oral administration as 400-mg pink film-coated oblong tablets imprinted Trent