Medical Editor: John P. Cunha, DO, FACOEP Last updated on RxList: 2/3/2023

Drug Summary

What Is Asclera?

Asclera (polidocanol injection) is a sclerosing agent used to treat small uncomplicated spider veins and varicose veins in the legs. Asclera will not treat varicose veins that are larger than 3 millimeters (about one-eighth of an inch) in diameter. Asclera is not a cure for varicose veins and the effects of this medication may not be permanent.

What Are Side Effects of Asclera?

Asclera may cause serious side effects including:

  • hives, 
  • difficulty breathing, 
  • swelling of your face, lips, tongue, or throat, 
  • sneezing, 
  • runny nose
  • severe pain, burning, or other irritation in your leg, 
  • discoloration or skin changes were an injection was given, 
  • sudden severe headache, 
  • confusion, 
  • problems with vision, speech, or balance, 
  • pain, swelling, warmth, or redness in one or both legs, 
  • severe numbness, 
  • trouble breathing, 
  • bounding heartbeats, 
  • fluttering in your chest, 
  • confusion, and
  • lightheadedness

Get medical help right away, if you have any of the symptoms listed above.

Common side effects of Asclera include:

  • mild numbness or tingling,
  • headache,
  • dizziness,
  • increased hair growth on the treated leg, or
  • injection site reactions (swelling, pain, warmth, itching, bruising, irritation, discoloration, and clotting)

Seek medical care or call 911 at once if you have the following serious side effects:

  • Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
  • Serious heart symptoms such as fast, irregular, or pounding heartbeats; fluttering in your chest; shortness of breath; and sudden dizziness, lightheadedness, or passing out;
  • Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors.

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

Dosage for Asclera

The dose of Asclera for spider veins (varicose veins ≤ 1 mm in diameter), is 0.5%. For reticular veins (varicose veins 1 to 3 mm in diameter), use Asclera 1%. Use 0.1 to 0.3 mL per injection and no more than 10 mL per session.

What Drugs, Substances, or Supplements Interact with Asclera?

Asclera During Pregnancy and Breastfeeding

Asclera may interact with other drugs. Tell your doctor all medications and supplements you use. During pregnancy, Asclera should be used only if prescribed. It is unknown if this drug passes into breast milk. Consult your doctor before breastfeeding.

Additional Information

Our Asclera (polidocanol injection) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

Drug Description


Asclera is a sterile, nonpyrogenic, and colorless to faintly greenish-yellow solution of polidocanol for intravenous use as a sclerosing agent.

The active ingredient, polidocanol is a non-ionic detergent, consisting of two components, a polar hydrophilic (dodecyl alcohol) and an apolar hydrophobic (polyethylene oxide) chain. Polidocanol has the following structural formula:

Asclera (polidocanol) - Structural Formula  - Illustration

C12H25(OCH2CH2)nOH Polyethylene glycol monododecyl ether Mean extent of polymerization (n) : Approximately 9 Mean molecular weight : Approximately 600

Each mL contains 5 mg (0.5%) or 10 mg (1.0%) polidocanol in water for injection with 5% (v/v) ethanol at pH 6.5-8.0; disodium hydrogen phosphate dihydrate, potassium dihydrogen phosphate are added for pH adjustment.

Indications & Dosage


Asclera® (polidocanol) is indicated to sclerose uncomplicated spider veins (varicose veins ≤1 mm in diameter) and uncomplicated reticular veins (varicose veins 1 to 3 mm in diameter) in the lower extremity. Asclera has not been studied in varicose veins more than 3 mm in diameter.


For intravenous use only. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. Do not use if particulate matter is seen or if the contents of the vial are discolored or if the vial is damaged in any way.

For spider veins (varicose veins ≤1 mm in diameter), use Asclera 0.5%. For reticular veins (varicose veins 1 to 3 mm in diameter), use Asclera 1%. Use 0.1 to 0.3 mL per injection and no more than 10 mL per session.

Use a syringe (glass or plastic) with a fine needle (typically, 26- or 30-gauge). Insert the needle tangentially into the vein and inject the solution slowly while the needle is still in the vein. Apply only gentle pressure during injection to prevent vein rupture. After the needle has been removed and the injection site has been covered, apply compression in the form of a stocking or bandage. After the treatment session, encourage the patient to walk for 15 to 20 minutes. Keep the patient under observation to detect any anaphylactic or allergic reaction [see WARNINGS AND PRECAUTIONS].

Maintain compression for 2 to 3 days after treatment of spider veins and for 5 to 7 days for reticular veins. For extensive varicosities, longer compression treatment with compression bandages or a gradient compression stocking of a higher compression class is recommended. Post-treatment compression is necessary to reduce the risk of deep vein thrombosis.

Repeat treatments may be necessary if the extent of the varicose veins requires more than 10 mL. These treatments should be separated by 1 to 2 weeks.

Small intravaricose thrombi that develop may be removed by microthrombectomy.


Dosage Forms And Strengths

Asclera is available as a 0.5% and 1% solution in 2 mL glass ampules.

Storage And Handling

Asclera is supplied in single-use, preservative free ampules in the following packages:

NDC 46783-121-52 Five 0.5% ampules (2 mL)
NDC 46783-221-52 Five 1.0% ampules (2 mL)

Each ampule is intended for immediate use in a single patient. Each unopened ampule is stable up to three years.

Store at 15-30°C; (59-86°F).

Manufactured by: Chemische Fabrik Kreussler & Co. GmbH 65203 Wiesbaden GERMANY. Revised: Sep 2019

Side Effects & Drug Interactions


Clinical Study Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

In 5 controlled randomized clinical trials, Asclera has been administered to 401 patients with small or very small varicose veins (reticular and spider veins) and compared with another sclerosing agent and with placebo. Patients were 18 to 70 years old. The patient population was predominately female and consisted of Caucasian and Asian patients.

Table 1 shows adverse events more common with Asclera or sodium tetradecyl sulfate (STS) 1% than with placebo by at least 3% in the placebocontrolled EASI study [see Clinical Studies]. All of these were injection site reactions and most were mild.

Table 1: Adverse Reactions in EASI-study

ASCLERA (180 patients)STS 1% (105 patients)Placebo (53 patients)
Injection site haematoma42%65%19%
Injection site irritation41%73%30%
Injection site discoloration38%74%4%
Injection site pain24%31%9%
Injection site pruritus19%27%4%
Injection site warmth16%21%6%
Injection site thrombosis6%1%0%

Ultrasound examinations at one week (±3 days) and 12 weeks (±2 weeks) after treatment did not reveal deep vein thrombosis in any treatment group.

Post-Marketing Safety Experience

The following adverse reactions have been reported during use of polidocanol in world-wide experience. Because these reactions are reported voluntarily from a population of uncertain size and without a control group, it is not possible to estimate their frequency reliably or to establish a causal relationship to drug exposure.

Immune system disorders: Anaphylactic shock, angioedema, urticaria generalized, asthma

Nervous system disorders: Cerebrovascular accident, migraine, paresthesia (local), loss of consciousness, confusional state, dizziness

Cardiac disorders: Cardiac arrest, palpitations

Vascular disorders: Deep vein thrombosis, pulmonary embolism, syncope vasovagal, circulatory collapse, vasculitis

Respiratory, thoracic and mediastinal disorders: Dyspnea

Skin and subcutaneous tissue disorders: Skin hyperpigmentation, dermatitis allergic, hypertrichosis (in the area of sclerotherapy)

General disorders and injection site conditions: Injection site necrosis, pyrexia, hot flush

Injury, poisoning and procedural complications: Nerve injury


No drug-drug interactions have been studied with Asclera.

Warnings & Precautions


Included as part of the "PRECAUTIONS" Section



Severe allergic reactions have been reported following polidocanol use, including anaphylactic reactions, some of them fatal. Severe reactions are more frequent with use of larger volumes (> 3 mL). Minimize the dose of polidocanol. Be prepared to treat anaphylaxis appropriately.

Severe adverse local effects, including tissue necrosis, may occur following extravasation; therefore, take care in intravenous needle placement and use the smallest effective volume at each injection.

After the injection session is completed, apply compression with a stocking or bandage, and have the patient walk for 15-20 minutes. Keep the patient under supervision during this period to treat any anaphylactic or allergic reaction [see DOSAGE AND ADMINISTRATION].

Venous Thrombosis And Pulmonary Embolism

Asclera can cause venous thrombosis and subsequent pulmonary embolism or other thrombotic events. Follow administration instructions closely and monitor for signs of venous thrombosis after treatment. Patients with reduced mobility, history of deep vein thrombosis or pulmonary embolism, or recent (within 3 months) major surgery, prolonged hospitalization or pregnancy are at increased risk for developing thrombosis.

Arterial Embolism

Stroke, transient ischemic attack, myocardial infarction, and impaired cardiac function have been reported in close temporal relationship with polidocanol administration. These events may be caused by air embolism when using the product foamed with room air (high nitrogen concentration) or thromboembolism. The safety and efficacy of polidocanol foamed with room air has not been established and its use should be avoided.

Tissue Ischemia And Necrosis

Intra-arterial injection or extravasation of polidocanol can cause severe necrosis, ischemia or gangrene. Take care in intravenous needle placement and use the smallest effective volume at each injection site. After the injection session is completed, apply compression with a stocking or bandage and have patients walk for 15-20 minutes. If intra-arterial injection of polidocanol occurs, consult a vascular surgeon immediately.

Nonclincal Toxicology

Carcinogenesis, Mutagenesis, Impairment Of Fertility

Long-term studies to evaluate carcinogenic potential have not been conducted with polidocanol. Polidocanol was negative in bacterial reverse mutation assays in Salmonella and E. coli, and in a micronucleus assay conducted in mice. Polidocanol induced numerical chromosomal aberrations in cultured newborn Chinese hamster lung fibroblasts in the absence of metabolic activation.

Polidocanol did not affect reproductive performance (fertility) of rats when administered intermittently at dosages up to 10 mg/kg (approximately equal to the maximum human dose on the basis of body surface area).

Use In Specific Populations


Risk Summary

The available data from case reports on use of polidocanol-containing products, including ASCLERA, in pregnant women have not identified any drugassociated risk for major birth defects, miscarriage, or adverse maternal or fetal outcomes. Although none of these risks have been identified, there is minimal benefit in treating uncomplicated spider veins and reticular veins in the lower extremity during pregnancy and lower extremity varicosities that develop during pregnancy as they may spontaneously regress postpartum. The animal reproduction studies were conducted in a manner to achieve systemic exposure, while the intended clinical use is local exposure at the injection site with minimal to no systemic exposure; therefore, these data are not relevant to the intended clinical use (see Data).

The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.


Animal Data

Developmental reproductive toxicity testing was performed in rats and rabbits with intravenous administration. Polidocanol induced maternal and fetal toxicity in rabbits, including reduced mean fetal weight and reduced fetal survival, when administered during gestation days 6-20 at doses of 4 and 10 mg/kg, but it did not cause skeletal or visceral abnormalities. No adverse maternal or fetal effects were observed in rabbits at a dose of 2 mg/kg. No evidence of teratogenicity or fetal toxicity was observed in rats dosed during gestation days 6-17 with doses up to 10 mg/kg. Polidocanol did not affect the ability of rats to deliver and rear pups when administered intermittently by intravenous injection from gestation day 17 to post-partum day 21 at doses up to 10 mg/kg.

These studies were conducted in a manner to achieve systemic exposure, while the intended clinical use is local exposure at the injection site with minimal to no systemic exposure; therefore, these data are not relevant to the intended clinical use.


Risk Summary

There are no data on the presence of polidocanol in human milk, the effects on the breastfed infant, or the effects on milk production. A lactating woman may consider interrupting breastfeeding and pumping and discarding breast milk up to 8 hours after ASCLERA administration in order to minimize exposure to a breastfed infant.

Pediatric Use

The safety and effectiveness of Asclera in pediatric patients have not been established.

Geriatric Use

Clinical studies of Asclera did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects.

Overdose & Contraindications


Overdose may result in a higher incidence of localized reactions such as necrosis.


Asclera is contraindicated for patients with known allergy to polidocanol and patients with acute thromboembolic diseases.

Clinical Pharmacology


Mechanism Of Action

The active ingredient of Asclera is polidocanol.

Polidocanol is a sclerosing agent that locally damages the endothelium of blood vessels. When injected intravenously, polidocanol induces endothelial damage. Platelets then aggregate at the site of damage and attach to the venous wall. Eventually, a dense network of platelets, cellular debris, and fibrin occludes the vessel. Finally, the occluded vein is replaced with connective fibrous tissue.


Polidocanol has a concentration- and volume-dependent damaging effect on the endothelium of blood vessels.


During the major effectiveness study (EASI-trial), scheduled blood samples were taken from a sub-group of 22 patients to measure plasma levels of polidocanol after Asclera treatment of spider and reticular veins. Low systemic blood levels of polidocanol were seen in some patients.

The mean t1/2 of polidocanol in 4 patients with evaluable data receiving 4.5 -18.0 mg was 1.5 h.

Clinical Studies

Asclera was evaluated in a multicenter, randomized, double-blind, placebo- and comparator-controlled trial (EASI-study) in patients with spider or reticular varicose veins. A total of 338 patients were treated with Asclera [0.5% for spider veins (n=94), 1% for reticular veins (n=86)], sodium tetradecyl sulfate (STS) 1% (n=105), or placebo (0.9% isotonic saline solution) (n=53) for either spider or reticular veins. Patients were predominately female, ranging in age from 19 to 70 years. All of them received an intravenous injection in the first treatment session; repeat injections were given three and six weeks later if the previous injection was evaluated as unsuccessful (defined as 1, 2 or 3 on a 5-point scale, see below). Patients returned at 12 and 26 weeks after the last injection for final assessments.

The primary effectiveness endpoint was improvement of veins judged by a blinded panel. Digital images of the selected treatment area were taken prior to injection, compared with those taken at 12 weeks post-treatment, and rated on a 5-point scale (1 = worse than before, 2 = same as before, 3 = moderate improvement, 4 = good improvement, 5 = complete treatment success); results are shown in Table 2.

Table 2: Improvement of veins in digital photographs after 12 weeks and 26 weeks

Treatment GroupPolidocanol (n=155)STS (n=105)Placebo (n=53)
Digital Photograph Scores at 12 weeks
Mean ± SD4.5* ± 0.74.5* ± 0.72.2 ± 0.7
Digital Photograph Scores at 26 weeks
Mean ± SD4.5* ± 0.74.5* ± 0.82.2 ± 0.7
*p <0.0001 compared to placebo (Wilcoxon-Mann-Whitney test)

The secondary efficacy criterion was the rate of treatment success, pre-defined as a score of 4 or 5 with patients scoring 1, 2, or 3 considered treatment failures; results are shown in Table 3.

Table 3: Treatment success rates at 12 weeks and 26 weeks

Treatment Success*Polidocanol (n=155)STS (n=105)Placebo (n=53)
At 12 weeks (Visit 4)
At 26 weeks (Visit 5)
*Treatment success: Yes= Grade 4 to 5, No= Grade 1 to 3; derived from median of evaluation;
p<0.0001 compared to placebo.

At 12 and 26 weeks, patients' judgement of the results was assessed by showing them the digital images of their treatment area taken at baseline and asking them to rate their satisfaction with their treatment using a verbal rating scale (1 = very unsatisfied; 2 = somewhat unsatisfied; 3 = slightly satisfied; 4 = satisfied and 5 = very satisfied); results are shown in Table 4.

Table 4: Patient satisfaction after 12 weeks and 26 weeks

Polidocanol (N=155)STS (N=105)Placebo (N=53)
Patient satisfaction with treatment after 12 weeks (Visit 4)
Satisfied or very satisfied87%*64%14%
Patient satisfaction with treatment after 26 weeks (Visit 5)
Satisfied or very satisfied84%*63%16%
*p <0.0001 compared to STS and placebo

Medication Guide


Advise the patient to wear compression stockings or support hose on the treated legs continuously for 2 to 3 days and for 2 to 3 weeks during the daytime. Compression stockings or support hose should be thigh or knee high depending upon the area treated in order to provide adequate coverage.

Advise the patient to walk for 15 to 20 minutes immediately after the procedure and daily for the next few days.

For two to three days following treatment, advise the patient to avoid heavy exercise, sunbathing, long plane flights, and hot baths or sauna.

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