Efficacy and safety of comfrey root extract ointment in the treatment of acute upper or lower back pain: results of a double-blind, randomised, placebo controlled, multicentre trial
ABSTRACT The objective was to show the superiority of comfrey root extract ointment to placebo ointment in patients with acute upper or lower back pain.
The study was conducted as a double-blind, multicentre, randomised clinical trial with parallel group design over a period of 5 days (SD 1). The patients (n = 120, mean age 36.9 years) were treated with verum or placebo ointment three times a day, 4 g ointment per application. The trial included four visits.
The primary efficacy variable was the area under the curve (AUC) of the visual analogue scale (VAS) on active standardised movement values at visits 1 to 4. The secondary efficacy variables were back pain at rest using assessment by the patient on VAS, pressure algometry (pain-time curve; AUC over 5 days), global assessment of efficacy by the patient and the investigator, consumption of analgesic medication and functional impairment measured using the Oswestry disability index.
There was a significant treatment difference between comfrey extract and placebo regarding the primary variable. In the course of the trial the pain intensity on active standardised movement decreased on average (median) approximately 95.2% in the verum group and 37.8% in the placebo group.
The results of this clinical trial were clear-cut and consistent across all primary and secondary efficacy variables. Comfrey root extract showed a remarkably potent and clinically relevant effect in reducing acute back pain. For the first time a fast-acting effect of the ointment (1 h) was also witnessed.
- SourceAvailable from: Christiane Staiger[Show abstract] [Hide abstract]
ABSTRACT: This randomised, multicentre, double-blind, three-arm, placebo-controlled trial compared a topical combination of 35% comfrey root extract plus 1.2% methyl nicotinate versus a single preparation of methyl nicotinate or placebo cream for relief of acute upper or low back pain. 379 patients were randomly assigned to three groups (combination, n = 163; methyl nicotinate, n = 164; placebo, n = 52). They applied a 12 cm layer of cream three times daily for 5 days. The primary efficacy variable was the area under the curve (AUC) of the visual analogue scale (VAS) on active standardised movement values at visits 1 to 4. Secondary measures included back pain at rest, pressure algometry, consumption of analgesic medication, functional impairment measured with Oswestry Disability Index, and global assessment of response. The AUC of the VAS on active standardised movement was markedly smaller in the combination treatment group than in the methyl nicotinate and in the placebo group (ANOVA: p < 0.0001). The combination demonstrated superiority to the two other treatment arms, while methyl nicotinate displayed a considerable effect as well. Copyright © 2012 John Wiley & Sons, Ltd.Phytotherapy Research 06/2013; 27(6). DOI:10.1002/ptr.4790 · 2.40 Impact Factor
Article: Comfrey: A Clinical Overview[Show abstract] [Hide abstract]
ABSTRACT: Comfrey has a centuries-old tradition as a medicinal plant. Today, multiple randomized controlled trials have demonstrated the efficacy and safety of comfrey preparations for the topical treatment of pain, inflammation and swelling of muscles and joints in degenerative arthritis, acute myalgia in the back, sprains, contusions and strains after sports injuries and accidents, also in children aged 3 or 4 and over. This paper provides information on clinical trials and non-interventional studies published on comfrey to date and further literature, substantiating the fact that topical comfrey preparations are a valuable therapy option for the treatment of painful muscle and joint complaints. Copyright © 2012 John Wiley & Sons, Ltd.Phytotherapy Research 04/2012; 26(10):1441-8. DOI:10.1002/ptr.4612 · 2.40 Impact Factor
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ABSTRACT: The present work evaluates wound healing activity of leaves extracts of Symphytum officinale L. (comfrey) incorporated in three pharmaceutical formulations. Wound healing activity of comfrey was determined by qualitative and quantitative histological analysis of open wound in rat model, using allantoin as positive control. Three topical formulations, carbomer gel, glycero-alcoholic solution and O/W emulsion (soft lotion) were compared. The histological analysis of the healing process shows significant differences in treatment, particularly on its intensity and rate. The results indicate that emulsion containing both extracts, commercial and prepared, induced the largest and furthest repair of damaged tissue. This could be evidenced from day 3 to 28 by increase in collagen deposition from 40% to 240% and reduction on cellular inflammatory infiltrate from 3% to 46%. However, 8% prepared extract in emulsion presented the best efficacy. This work clearly demonstrates that comfrey leaves have a wound healing activity. The O/W emulsion showed to be the vehicle most effective to induce healing activity, particularly with extracts obtained from comfrey leaves collected in Minas Gerais state in Brazil. It shows the best efficacy to control the inflammatory process and to induce collagen deposition at 8% concentration.Pharmazie 04/2012; 67(4):355-60. DOI:10.1691/ph.2012.1563 · 1.00 Impact Factor