Efficacy and tolerance of a comfrey root extract (Extr. Rad. Symphyti) in the treatment of ankle distorsions: results of a multicenter, randomized, placebo-controlled, double-blind study.

Comfrey (Symphytum officinale L.) is a medicinal plant with anti-inflammatory, analgesic and tissue regenerating properties. In a double-blind, multicenter, randomized, placebo-controlled, group comparison study on patients suffering from unilateral acute ankle sprains (n = 142, mean age 31.8 years, 78.9% male), the percutaneous efficacy of an ointment of comfrey extract (Kytta-Salbe f, four treatments per day for 8 days) was confirmed decisively. Compared to placebo, the active treatment was clearly superior regarding the reduction of pain (tonometric measurement, p<0.0001, as the primary efficacy variable) and ankle edema (figure-of-eight method, p = 0.0001). Statistically significant differences between active treatment and placebo could also be shown for ankle mobility (neutral zero method), and global efficacy. Under active treatment, no adverse drug reactions were reported. The good local and global tolerance of the trial medication could also be confirmed. The study results are consistent with the known pre-clinical and clinical data concerning comfrey.

[Therapeutic characteristance and tolerance of topical comfrey preparations. Results of an observational study of patients]. / Therapeutische Eigenschaften und Verträglichkeit topischer Beinwellzubereitungen. Ergebnisse einer Beobachtungsstudie an Patienten.

AIM: To analyze the anti-inflammatory and analgetic properties of the topical comfrey, preparations Kytta-Salbe f, Kytta-Plasma f and Kytta-Balsam f applied to bruises, sprains and distortions and painful conditions of the muscles and joints. METHOD: A prospective open multicentric observational study complying with paragraph 67(6) of the AMG and involving 162 general practitioners. During the two-week period of observation, the patients received an average of one to three applications of the comfrey preparation per day. All 492 questionnaires were evaluated. Efficacy and tolerability were assessed by both physician and patient. RESULTS: Pain at rest and on movement, as also tenderness, improved in the overall observation group by an average of 45-47%. The duration of morning joint stiffness decreased from 20 minutes initially to 3 minutes. During the course of treatment with comfrey, more than two-thirds of the patients were able to reduce or even discontinue their intake of non-steroidal anti-inflammatory drugs and other specific concomitant medication. In most of the cases, both effectiveness and tolerability were assessed to be excellent or good. CONCLUSION: The results of the study confirm the effectiveness and tolerability of the topical comfrey preparation investigated in the treatment of bruises, sprains and distortions as well as painful conditions affecting muscles and joints.