Haemorrheological agent (xanthine derivative) Pregnancy: Pentoxifylline should not be administered during pregnancy - there is no information on use in pregnancy, although no untoward effects have been found in animal studies. Pentoxifylline passes into breast milk in minute quantities; the possible risks and benefits must be weighed before administration to breast-feeding mothers. (US labelling assigns Pregnancy Category C.)

Pentoxifylline (Oxpentifylline)

Brand names: Trental

Pentoxifylline (oxpentifylline) is a methylxanthine derivative that has been used to relieve symptoms of peripheral arterial disease with 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)

Route: Oral - taken with or immediately after meals, swallowed whole with plenty of water

Frequency: Three times daily

Source: UK SPC (eMC) section 4.2 for Pentoxifylline 400 mg Modified-release tablet (https://www.medicines.org.uk/emc/product/100292/smpc). VERBATIM: 'The recommended initial dose is 1 tablet (400 mg) three times daily; two tablets daily may prove sufficient in some patients, particularly for maintenance therapy.' Elderly: no special dosage requirements. Hepatic impairment: in patients with severely impaired liver function the dosage may need to be reduced (section 4.4). Particularly careful monitoring is required in patients with hypotension or severe coronary artery disease (a transient hypotensive effect is possible and might, in isolated cases, reduce coronary artery perfusion), in impaired renal function, and in patients also taking anti-vitamin K agents, platelet aggregation inhibitors, antidiabetic agents, ciprofloxacin or theophylline. Paediatric: the SPC states pentoxifylline is not suitable for use in children. US labelling agrees on 400 mg three times a day with meals and adds: if digestive or central nervous system side effects develop, lower the dosage to one tablet twice a day (800 mg/day) and discontinue if side effects persist; treatment should be continued for at least 8 weeks; in severe renal impairment (creatinine clearance below 30 mL/min) reduce the dose to 400 mg once a day; dosing information cannot be provided for hepatic impairment.

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. Section 4.4 adds that in patients with a creatinine clearance of 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 the active substance, to other methylxanthines, or to any of the excipients
Cerebral haemorrhage
Extensive retinal haemorrhage
Acute myocardial infarction
Severe cardiac arrhythmias

Side effects

Dizziness and headache
Gastrointestinal disorder, epigastric discomfort, abdominal distension, nausea, vomiting, diarrhoea, constipation
Pruritus, erythema, urticaria, hot flush, rash
Haemorrhage (very rare bleeding events e.g. skin, mucosa, gastrointestinal, genitourinary) and hypotension
Arrhythmia, tachycardia and angina pectoris; anaphylactic/anaphylactoid reactions and angioedema also reported (frequencies unknown)

Interactions

Anti-vitamin K anticoagulants - post-marketing cases of increased anticoagulant activity; monitor anticoagulant activity when pentoxifylline is introduced or the dose is changed
Platelet aggregation inhibitors (e.g. clopidogrel, eptifibatide, tirofiban, epoprostenol) - potential additive effect and increased risk of bleeding
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, with intensification of adverse reactions
Insulin and oral hypoglycaemic agents - high doses of pentoxifylline injection have in rare cases intensified the hypoglycaemic action; monitor patients treated for diabetes mellitus carefully
Antihypertensive agents - pentoxifylline may potentiate their effect and the dosage of the antihypertensive may need to be reduced

Clinical monograph

How it works

It improves red blood cell deformability and reduces blood viscosity and platelet aggregation, which may enhance microcirculatory blood flow.

Prescribing in practice

It is contraindicated after recent haemorrhage, including cerebral or retinal bleeding, because of its effects on blood flow and platelets.
Use with caution in hypotension, severe cardiac arrhythmia and in renal or hepatic impairment.
Modified-release tablets should be swallowed whole.

Monitoring

Monitor blood pressure and review for symptomatic benefit, particularly in patients with cardiovascular or renal disease.

Counselling the patient

Swallow modified-release tablets whole with water and do not crush them.
Report dizziness, palpitations or any signs of bleeding.
Continue exercise and address risk factors such as smoking.

Evidence & guidelines

Evidence of benefit in intermittent claudication is modest, and NICE recommends supervised exercise and risk-factor management as first-line care.

Reference: NICE NG19 PAD Guidelines; 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