Hemorheological Agent (Methylxanthine) Pregnancy: There is no information on the use of pentoxifylline in pregnancy, but no untoward effects have been found in animal studies. Pentoxifylline should not be administered during pregnancy. It passes into breast milk in minute quantities; because insufficient experience has been gained, the possible risks and benefits must be weighed before administration to breastfeeding mothers.

Pentoxifylline

Brand names: Trental

Pentoxifylline is an oral xanthine-derivative haemorheological agent used to improve symptoms of peripheral arterial disease such as intermittent claudication.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 400 mg (one modified-release tablet) three times daily as the recommended initial dose; two tablets daily (800 mg) may prove sufficient in some patients, particularly for maintenance therapy

Route: Oral — tablets should be taken with or immediately after meals, and swallowed whole with plenty of water

Frequency: Three times daily (initial); twice daily may suffice for maintenance in some patients

Source is the UK SPC for 'Pentoxifylline 400 mg Modified-release tablet' (eMC product 100292). The SPC states no maximum dose. Elderly: no special dosage requirements. Paediatric: 'Pentoxifylline is not suitable for use in children.' Hepatic: in patients with severely impaired liver function the dosage may need to be reduced (§4.4). Use with caution in hypotension or severe coronary artery disease — a transient hypotensive effect is possible and in isolated cases might reduce coronary artery perfusion. Discontinue immediately at the first signs of an anaphylactic/anaphylactoid reaction. §4.5 was truncated at source fetch, so the interaction list is partial. The US label fetched as cross-check gives the same 400 mg three times a day with meals, adds that treatment should be continued for at least 8 weeks, and that dose-related digestive/CNS side effects should prompt reduction to one tablet twice a day (800 mg/day) before discontinuation — not carried into the dose field, which follows the UK SPC.

Dose adjustments

Renal

In patients with impairment of renal function (creatinine clearance below 30 mL/min) a dose reduction by approximately 30% to 50% may be necessary, guided by individual tolerance (§4.2). §4.4 adds that in patients with creatinine clearance less than 30 mL/min it may be necessary to reduce the daily dose to one or two tablets to avoid accumulation.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to pentoxifylline, to other methylxanthines, or to any of the excipients
Cerebral haemorrhage
Extensive retinal haemorrhage
Acute myocardial infarction
Severe cardiac arrhythmias

Side effects

Dizziness, headache; aseptic meningitis (predominantly in patients with underlying connective tissue disorders)
Gastrointestinal disorder, epigastric discomfort, abdominal distension, nausea, vomiting, diarrhoea, constipation, hypersalivation
Pruritus, erythema, urticaria, hot flush, rash
Haemorrhage and hypotension
Thrombocytopenia, leukopenia/neutropenia; transaminases increased; arrhythmia, tachycardia, angina pectoris; anaphylactic/anaphylactoid reactions and angioedema

Interactions

Insulin and oral hypoglycaemic agents — high doses of pentoxifylline injection have in rare cases intensified the hypoglycaemic action; patients on medication for diabetes mellitus should be carefully monitored
Anti-vitamin K anticoagulants — post-marketing cases of increased anticoagulant activity; monitor anticoagulant activity when pentoxifylline is introduced or the dose changed
Antihypertensive agents — pentoxifylline may potentiate the effect and the dose of the antihypertensive may need to be reduced
Ketorolac — should not be given concomitantly; increased risk of bleeding and/or prolongation of prothrombin time
Theophylline — concomitant administration may increase theophylline levels in some patients, with intensification of theophylline adverse effects
Ciprofloxacin — may increase the serum concentration of pentoxifylline in some patients, intensifying adverse reactions
Platelet aggregation inhibitors (e.g. clopidogrel, eptifibatide, tirofiban, epoprostenol) — potential additive effect and increased risk of bleeding

Clinical monograph

How it works

It improves the flexibility of red blood cells and reduces blood viscosity and platelet aggregation, thereby enhancing microcirculatory blood flow to ischaemic tissue.

Prescribing in practice

It increases bleeding risk and should be used cautiously with anticoagulants and antiplatelet agents and avoided in active bleeding such as recent cerebral or retinal haemorrhage.
It is a symptomatic treatment that supplements, but does not replace, exercise therapy and cardiovascular risk-factor control.
Use caution in significant renal or hepatic impairment and in severe cardiac arrhythmias or hypotension.

Monitoring

Review symptomatic benefit such as walking distance and watch for bleeding, gastrointestinal upset and dizziness.

Counselling the patient

Take with or after food to reduce stomach upset and swallow modified-release tablets whole.
Report any unusual bleeding or bruising.

Evidence & guidelines

Used for intermittent claudication on the basis of haemorheological trial data, with modest symptomatic benefit recognised in vascular practice.

Reference: Cochrane review 2012; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Pathways