What the label lists and what reports show
Pentoxifylline side effects
Pentoxifylline's FDA label lists its adverse reactions in its own words. FAERS holds 4,297 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is fatigue (458 reports).
- Generic listed
Check it at the source: the pentoxifylline FDA label on DailyMed (effective May 15, 2026, Rising Pharma Holdings, Inc.); the FDA FAERS public dashboard.
What does the label list?
From the label: adverse reactionsClinical trials were conducted using either extended-release pentoxifylline tablets for up to 60 weeks or immediate-release pentoxifylline capsules for up to 24 weeks. Dosage ranges in the tablet studies were 400 mg bid to tid and in the capsule studies, 200 mg to 400 mg tid. The table summarizes the incidence (in percent) of adverse reactions considered drug related, as well as the numbers of patients who received extended-release pentoxifylline tablets, immediate-release pentoxifylline capsules, or the corresponding placebos. The incidence of adverse reactions was higher in the capsule studies (where dose related increases were seen in digestive and nervous system side effects) than in the tablet studies. Studies with the capsule include domestic experience, whereas studies with the extended-release tablets were conducted outside the U.S. …
INCIDENCE (%) OF SIDE EFFECTS
This table is printed in the PENTOXIFYLLINE label published by Major Pharmaceuticals of September 22, 2025; the label quoted above does not print one.
| (Number of Patients at Risk) | Pentoxifylline (321) | Placebo (128) | Pentoxifylline (177) | Placebo (138) |
|---|---|---|---|---|
| Discontinued for Side Effect | 3.1 | 0 | 9.6 | 7.2 |
| Angina/Chest Pain | 0.3 | - | 1.1 | 2.2 |
| Belching/Flatus/Bloating | 0.6 | - | 9.0 | 3.6 |
| 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 |
| Dizziness | 1.9 | 3.1 | 11.9 | 4.3 |
| Headache | 1.2 | 1.6 | 6.2 | 5.8 |
| Tremor | 0.3 | 0.8 | - | - |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
Source: FDA drug label, Rising Pharma Holdings, Inc., effective May 15, 2026 (SPL set cd840a2c-2a0e-4b2b-84ff-a0406bb6fa37), via openFDA; the full label on DailyMed
What do FAERS reports show?
4,297 reports list pentoxifylline among the medicines taken, each a report of something that happened, not proof the medicine caused it; 746 are coded as a death and 1,650 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 23 reactions below, 8 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Pentoxifylline: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions