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Sclerosant Pregnancy: §4.6, verbatim: 'Safety for use in pregnancy has not been established. Studies in animals showed reproductive toxicity, but no teratogenic potential. Treatment should be postponed until after childbirth. Aethoxysklerol should be used only when clearly needed for symptomatic relief and when the potential benefits outweigh the potential hazards to the fetus.' BREAST-FEEDING: 'It is not known whether lauromacrogol 400 is excreted in human milk. Caution should be exercised when used in nursing mothers. If sclerotherapy is necessary during breast-feeding, it is advisable to suspend breast-feeding for 2-3 days.' FERTILITY: 'It is not known whether lauromacrogol 400 affects fertility.'

Lauromacrogol 400 (polidocanol)

Brand names: Fibro-Vein, Sclerovein

Lauromacrogol 400 (polidocanol) is a sclerosant used to treat varicose veins, smaller varicosities and telangiectasia.

Adult dose

Dose: Sclerotherapy of varicose veins — concentration is chosen by vein type and diameter, and volume is given per puncture. TELANGIECTASIAS (spider veins): 0.1-0.2 ml of 2.5 mg/ml or 5 mg/ml per puncture. CENTRAL VEINS OF TELANGIECTASIAS: 0.1-0.2 ml of 2.5 mg/ml, 5 mg/ml or 10 mg/ml per puncture. RETICULAR VEINS: 0.1-0.3 ml of 10 mg/ml per puncture. SMALL VARICOSE VEINS: 0.1-0.3 ml of liquid 10 mg/ml per puncture; as 10 mg/ml microfoam, up to 4-6 ml per puncture for tributary (collateral) varices and up to 2-4 ml per puncture for perforating veins. MEDIUM-SIZED VARICOSE VEINS: several injections of up to 2 ml of liquid 20 mg/ml or 30 mg/ml per injection; as 20 mg/ml microfoam, up to 2 ml per puncture for perforating or tributary varices; as 20 mg/ml or 30 mg/ml microfoam for saphenous veins, up to 4 ml per puncture for the small saphenous and up to 6 ml for the great saphenous. LARGE VARICOSE VEINS: several injections of up to 2 ml of liquid 30 mg/ml per injection; as 30 mg/ml microfoam for saphenous veins, up to 4 ml per puncture for the small saphenous and up to 6 ml for the great saphenous.
Route: Intravenous injection into the target vein (sclerotherapy), as liquid or as sclerosing microfoam. 'All injections must be given intravenously; the position of the needle should be checked (e.g. by aspiration of blood).' Specialist use only: 'Aethoxysklerol should only be administered by healthcare professionals experienced in sclerotherapy and the required preparation techniques.' Direct puncture and injection into non-visible veins should be guided by duplex ultrasound; the needle should not be smaller than 25G. Single-use parenteral product — once opened, use immediately and discard any unused portion.
Frequency: Per treatment session. 'Depending on the degree and extent of the varicose veins, several treatments may be required.' The microfoam ceiling is expressed 'per session and day'.
Max: Maximum 10 ml of microfoam per session and day (§4.2, verbatim: 'When applying as a sclerosing microfoam, it is recommended not to exceed the total dose of 10 ml microfoam (the sum of the liquid and air components) per session and day - irrespective of the patient's body weight and concentration of lauromacrogol 400.'). A SECOND, BODY-WEIGHT-DEPENDENT daily ceiling on lauromacrogol 400 itself also applies to every presentation; because it is weight-dependent it cannot be reduced to a fixed number here and is quoted verbatim, with the SPC's own worked example and volume equivalents, in the notes field — read it before treating.
WEIGHT-BASED DAILY CEILING (§4.2, verbatim — applies to liquid and microfoam alike): 'Generally, the dose of 2 mg lauromacrogol 400 per kg body weight per day should not be exceeded. For a patient weighing 70 kg, a total of up to 140 mg lauromacrogol 400 can be injected.' The SPC then gives the volumes containing that 140 mg: 56 ml of 2.5 mg/ml, 28 ml of 5 mg/ml, 14 ml of 10 mg/ml, 7 ml of 20 mg/ml, or 4.6 ml of 30 mg/ml. The medium-sized and large varicose-vein regimens are each qualified 'without exceeding the maximum daily dose'. || CHOOSING THE CONCENTRATION (§4.2, verbatim): 'Different concentrations of Aethoxysklerol are required, depending on the type and size of the varicose veins to be treated. If several concentrations are stated for a certain type of vein, the diameter of the vein and the patient's individual situation should be considered. In case of doubt the lower concentration should be chosen.' The SPC's concentration/vein-type table lists 2.5, 5, 10, 20 and 30 mg/ml. || NEVER INTRA-ARTERIAL (§4.4, verbatim): 'Sclerosants must never be injected intra-arterially because this can cause severe necrosis which may necessitate amputation. A vascular surgeon must be called in immediately if any such incident occurs. In certain body regions such as in the foot or malleolar region, the risk of inadvertent intra-arterial injection may be increased. Therefore, in these regions only small amounts should be used in low concentrations with particular care.' Also: 'Adverse effects, including tissue necrosis, may occur following extravasation, therefore it is important to exercise extreme care in intravenous needle placement and use the minimal effective volume at each injection site.' || TECHNIQUE (§4.2): injections are usually carried out in a leg placed horizontally; for microfoam the leg can be horizontal or elevated approximately 30-45 degrees; for telangiectasias very fine needles (e.g. insulin needles) are used, the puncture carried out tangentially and the injection given slowly. || COMPRESSION (§4.2, verbatim): 'Once the injection site has been covered, a tight compression bandage or elastic stocking should be applied. After that, the patient should walk for 30 minutes, preferably within reach of the practice. After sclerotherapy with liquid Aethoxysklerol, compression is applied immediately. After sclerotherapy with microfoam the patient's leg is initially immobilised for 2-5 minutes. Valsalva's manoeuvre and muscle activation should be avoided during this time. Compression should not be applied immediately but 5 to 10 minutes after injection. Compression should be applied for a few days up to several weeks, depending on the extent and severity of the varicose veins.' || ELDERLY (§4.2): 'No specific dose recommendations apply.'

Dose adjustments

Renal

§4.2, verbatim (hepatic and renal impairment are addressed together): 'No pharmacokinetic studies have been performed in patients with hepatic or renal impairment. The use of sclerotherapy should be cautious and assessed in patients with moderate hepatic or renal impairment, in whom the treatment benefit clearly outweighs the risk. Aethoxysklerol is not recommended for use in patients with severe hepatic or renal impairment.' No numerical dose reduction is given.

Hepatic

§4.2, verbatim (same combined statement): 'No pharmacokinetic studies have been performed in patients with hepatic or renal impairment. The use of sclerotherapy should be cautious and assessed in patients with moderate hepatic or renal impairment, in whom the treatment benefit clearly outweighs the risk. Aethoxysklerol is not recommended for use in patients with severe hepatic or renal impairment.' No numerical dose reduction is given.

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via the eMC — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Known hypersensitivity to lauromacrogol 400 or to any of the excipients (§4.3)
  • Uncontrolled systemic diseases — such as diabetes mellitus, toxic hyperthyroidism, tuberculosis, asthma, neoplasm, systemic infections, blood dyscrasias, acute respiratory or skin diseases (§4.3)
  • Immobility — inability to walk due to any cause, i.e. the patient is immobile (§4.3)
  • Severe arterial occlusive disease (Fontaine stages III and IV) (§4.3)
  • Thromboembolic diseases (§4.3)
  • High risk of thrombosis — e.g. known hereditary thrombophilia, or patients with multiple risk factors such as use of hormonal contraceptives or hormone replacement therapy, obesity, smoking, and extended periods of immobility (§4.3)
  • MICROFOAM ONLY, an additional contraindication (§4.3): known symptomatic right-to-left shunt, e.g. symptomatic patent foramen ovale (PFO)
  • Not a contraindication but an absolute technique rule (§4.4): 'Sclerosants must never be injected intra-arterially because this can cause severe necrosis which may necessitate amputation.'
  • Not a contraindication but a stop rule (§4.4): 'Sclerotherapy should not be undertaken if significant valvular incompetence is suspected following the evaluation.'
  • Not licensed in children — §4.2: 'There is no relevant use of Aethoxysklerol in the paediatric population in children or adolescents for the indication of sclerotherapy of varicose veins of the lower extremities.'

Side effects

  • Most common overall (§4.8, verbatim): 'short-term injection site pain, injection site intravaricose blood clots and temporary skin discolouration after treatment' — temporary in most cases
  • Most serious reported (§4.8, verbatim): 'anaphylactic shock, pulmonary embolism, cerebrovascular accident, stress cardiomyopathy (Tako Tsubo) and cardiac arrest'
  • Common (§4.8): neovascularisation, haematoma; skin hyperpigmentation, ecchymosis; injection site pain (short-term), injection site thrombosis (local intravaricose blood clots)
  • Uncommon (§4.8): superficial thrombophlebitis, phlebitis; allergic dermatitis, contact urticaria, skin reaction, erythema; necrosis of skin and tissues, induration, swelling; nerve injury
  • Rare (§4.8): deep vein thrombosis; pain in extremity; migraine when using sclerosing microfoam
  • Very rare (§4.8): anaphylactic shock, angioedema, generalised urticaria, asthmatic attack; cerebrovascular accident (stroke, TIA), hemiparesis, headache, migraine, local paraesthesia, oral hypoaesthesia, loss of consciousness, confusional state, aphasia, ataxia, dizziness; cardiac arrest, palpitations, stress cardiomyopathy (Tako Tsubo); pulmonary embolism, vasovagal syncope, circulatory collapse, vasculitis; dyspnoea, chest discomfort, cough; dysgeusia, nausea, vomiting; hypertrichosis in the area of sclerotherapy; pyrexia, hot flush, asthenia, malaise; abnormal blood pressure, abnormal heart rate (tachycardia, bradycardia)
  • Visual impairment / visual disturbance — very rare, but 'rare' when using sclerosing microfoam (§4.8)
  • Paravenous (extravascular) injection (§4.8, verbatim): 'Local adverse reactions (e.g. necrosis), especially of the skin and of the underlying tissue (and, in rare cases, of the nerves), were observed when treating varicose veins in the leg after inadvertent injection into the surrounding tissue (paravenous injection). The risk increases with increasing Aethoxysklerol concentrations and volumes.'

Monitoring

  • Needle position at every injection (§4.2, verbatim): 'All injections must be given intravenously; the position of the needle should be checked (e.g. by aspiration of blood).'
  • Pre-procedure evaluation (§4.4, verbatim): 'Before treatment, the healthcare professional should investigate patient's risk factors and inform them about the risks of the technique. A thorough pre-procedure evaluation for valvular competency should be carried out as appropriate. Sclerotherapy should not be undertaken if significant valvular incompetence is suspected following the evaluation.'
  • Follow-up for DVT (§4.4, verbatim): 'The healthcare professional should see the patient again in the weeks after treatment to perform a clinical efficacy and safety evaluation. Patients should have post-treatment follow-up of sufficient duration to assess for the development of deep vein thrombosis. Adequate post-treatment compression may decrease the incidence of deep vein thrombosis.'
  • Immediately after microfoam injection (§4.2/§4.4): the leg is immobilised for 2-5 minutes and Valsalva manoeuvre and muscle activation are avoided; in patients with asymptomatic but known patent foramen ovale, use smaller volumes and avoid Valsalva in the minutes after injection
  • Patients who have had visual or neurological symptoms (e.g. migraine) after previous microfoam sclerotherapy (§4.4): 'the patients should lie down for a longer time and avoid Vaslava manoeuvre in the minutes after injection. Use smaller volumes in these patients.'
  • Visual inspection of the solution before use (§4.2): 'Solutions that contain particulate matter should not be used.'
  • Patients on anticoagulation (§4.4): 'Anticoagulation is not a contraindication to sclerotherapy. In general, special care should be taken in patients using anticoagulation medication.'

Clinical monograph

How it works

Injected into the vein it damages the endothelium, triggering localised thrombosis and fibrosis that obliterates the vessel lumen.

Prescribing in practice

  • Anaphylaxis and accidental intra-arterial injection causing tissue necrosis are recognised serious hazards; ensure resuscitation facilities and correct technique.
  • It is contraindicated in acute deep vein thrombosis and in patients confined to bed; administration should be by an experienced operator.
  • It is also available as a foam preparation for larger veins, which alters its distribution and efficacy.

Monitoring

Observe the patient for allergic reaction after injection and review the treated limb for thrombophlebitis or skin changes.

Counselling the patient

  • Wear compression as directed after treatment and stay mobile.
  • Report leg swelling, breathlessness or chest pain urgently as these may indicate a clot.

Evidence & guidelines

Sclerotherapy with polidocanol is an established option for varicose veins and telangiectasia, reflected in NICE guidance on varicose vein management (CG168).

Reference: NICE CG168; 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).

Related

Curated clinical cross-links plus same-class fallbacks.

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