Polidocanol Other names: Lauromacrogol 400

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

Application of a compression bandage following sclerotherapy of varices compresses the damaged vein walls so that excessive thrombus formation and recanalisation of the initially formed parietal thrombus are prevented. This gives rise to the desired transformation into fibrous tissue and hence sclerosis.

In addition, polidocanol has a local anaesthetic effect and locally and reversibly suppresses the excitability of the terminal sensory organs (receptors) as well as the conduction capacity of the sensory nerve fibres.

Six healthy subjects received an injection of 37 mg ¹⁴C-polidocanol as a strongly diluted solution into the great saphenous vein. The concentration-time course of polidocanol in plasma was biphasic – with a terminal elimination half-life of polidocanol and its labelled metabolites of 4.09 h. The AUC_∞ was 3.16 μg x h/ml and the total clearance 11.68 l/h. 89% of the administered dose were eliminated from the blood within the first 12 hours.

In another study, the plasma concentrations of parent polidocanol molecules were determined in 6 patients with varices (diameter >3 mm) after treatment with polidocanol 3%. The plasma half-life was 0.94 -1.27 h and the AUC_∞ 6.19-10.90 μg x h/ml. The mean total clearance was 12.4 l/h and the distribution volume 17.9 l.

In animal experiments, polidocanol has a relatively low acute toxicity. Safety pharmacological studies showed negative chronotropic, inotropic and dromotropic effects, with a blood pressure drop. Additional proarrhythmic effects were seen when other local anaesthetics were given concomitantly. After repeated administration of polidocanol, some animals of all species investigated showed histological alterations in the intestine, adrenal gland and liver, and rabbits additionally in the kidneys.

Polidocanol caused haematuria in all species investigated. At doses of 4 mg/kg body weight/day and higher, male rats showed an increase in liver weight after daily application on 7 consecutive days and an increase in ALAT (GPT) and ASAT (GOT) activity at doses of 14 mg/kg/day and higher.