Sclerotherapy for spider veins: what the FDA label covers, side effects and the risks

Sclerotherapy injects a solution into small leg veins so they close. The FDA-approved Asclera label, for the sclerosing agent polidocanol, covers uncomplicated spider veins, which it defines as varicose veins up to 1 mm across, and uncomplicated reticular veins, 1 to 3 mm across, in the legs.¹

Here is what the label says, the side effects seen in its trial and the warnings. It gives no dose and no technique. Whether to have it is for you and a clinician.

What the label covers

Polidocanol is a sclerosing agent. The label says Asclera is for intravenous use only, and that it hasn't been studied in varicose veins more than 3 mm across.¹ The label doesn't cover larger varicose veins. Sotradecol and Varithena are separate products with their own labels.

Side effects seen in the trial

The label reports the EASI study, in which 180 people received Asclera, 105 received a comparison agent, sodium tetradecyl sulfate 1%, and 53 received placebo. Bruising at the injection site (hematoma) was reported by 42% on Asclera against 19% on placebo, irritation by 41% and 30%, discoloration by 38% and 4%, pain by 24% and 9%, itching by 19% and 4%, and warmth by 16% and 6%. Neovascularisation, the growth of new small vessels, was 8% against 4%, and injection site thrombosis 6% against none. All of these were injection site reactions and most were mild.¹

Ultrasound exams one week and 12 weeks after treatment didn't show deep vein thrombosis in any group in that study.¹

Warnings

The label says severe allergic reactions have been reported after polidocanol, including anaphylaxis, some fatal, and that they are more frequent with larger volumes.¹ It warns that polidocanol can cause venous thrombosis and pulmonary embolism, a clot that travels to the lungs, and that people with reduced mobility, a history of deep vein thrombosis or pulmonary embolism, recent major surgery or prolonged hospitalization, or pregnancy are at increased risk.¹

It also reports stroke, transient ischemic attack, heart attack and impaired heart function close in time to polidocanol, possibly from air in foamed product or from clots, and says the safety of foam made with room air hasn't been established. Injecting into an artery, or leaking outside the vein, can cause tissue ischemia and necrosis, meaning loss of blood supply and tissue death.¹

The label says the drug must not be used by people with a known allergy to polidocanol or an acute thromboembolic disease.¹ On pregnancy, it says case reports haven't identified a drug-associated risk, but that there is minimal benefit in treating these veins during pregnancy, because veins that develop during pregnancy may spontaneously regress afterward.¹ Safety and effectiveness in children haven't been established.¹

What to ask

Which licensed professionals may inject depends on your state. See our guide to who may inject.

Here is what to bring to a consultation.

Cost

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Common questions