| Study |
Methods |
Participants |
Interventions |
Outcomes |
Notes |
| Frerick et al 32 |
RCT with two groups; period: 3 wk |
Three hundred twenty subjects with chronic nonspecific LBP divided equally between capsicum plaster group and placebo group. |
Topical plaster containing an ethanolic extract of cayenne pepper standardized to 22 μg/cm2 of capsaicinoids or placebo plaster. |
Outcomes: Arhus LBP rating scale, global assessment of efficacy by patient and investigator, global assessment of safety by patient and investigator. |
Adverse events: local drug reactions in 12 (7.5%) capsicum subjects and 5 (3.1%) placebo subjects. |
| Ginsberg and Fa-maey33 |
RCT with 40 patients assigned to 1 of 2 groups; period, 14 days. |
Forty patients with acute mechanical LBP were assigned to either the Rado-Salil (a capsicum containing cream) group (n = 20) or a placebo group (n = 20). Each patient was also given 45 paracetamol 250-mg tablets. No other analgesic, anti-inflammatory drug or physical treatment was allowed during the 12-wk period. Method of patient selection: clinical examination, standard radiological examination of the lumbar spine, routine laboratory tests. |
Rado-Salil ointment (containing 17.64 mg ethysalicylate, 26.47 mg methylsalicylate, 8.82 mg glycosalicylate, 8.82 mg salicylic acid, 4.41 mg camphor, 55.14 mg menthol and 15.44 mg capsicum oleoresin per 1 g) in the form of a 40 g stick applied as needed or a placebo (containing only the excipient with 3 times the amount of lavendula and bergamot essences) matched for appearance. |
Outcomes: pain evaluation on a 10-cm linear scale, duration of confinement to bed, muscular reflex contracture evaluation by the physician on a scale of 0–4, and spine mobility by determination of Schober's index, the finger-to-floor distance, the degree of lumbar extension, global appreciation of treatment by patient and physician. |
Adverse events: pruritus, one in placebo, one in Rado-Salil group. Local erythema and burning, 3 in the Rado-Salil group. |
| Keitel et al 16 |
RCT with two groups. No report of randomization method; period: 1 plaster per day at maximum pain site for 4–12 hr for 3 wk |
Patients were randomly allocated to a placebo plaster group (n = 77) and a capsicum plaster group (n = 77). A total of 132 patients completed the study with data being available for the intention-to-treat (ITT) analysis on 150 patients (P = 0.002). Twenty-two exclusions occurred due to premature discontinuation of the treatment (n = 19) failure to meet the inclusion criteria (n = 2) or unauthorized concurrent treatment (n = 1). Inclusion criteria: subjective back pain rating of 5 or more on an 11-grade visual analog scale (VAS) as well as a duration of back pain for a minimum of 3 mos at enrollment. Exclusion criteria: alcohol abuse, drug dependence, forms of specific back pain, concomitant systemic inflammatory rheumatic condition, no concurrent therapy for back pain. |
Topical plaster type application of Capsicum frutescens (cayenne) containing 12 mg of capsaicinoids per plaster. Matched placebo plaster. |
Primary outcome measure: Arhus low back rating scale. Secondary outcome measures: Global assessment of efficacy and tolerance by physician and patient. |
Adverse events: Twenty-four adverse events were reported (C = 15; P = 9). Most of these were warmth and itching locally. The C group had five cases of severe adverse events (inflammatory contact eczema, urticaria, minute hemorrhagic spots, and fasciculation or dermatitis) and the P group had two such cases (fasciculation or allergic dermatosis). A total of 16 patients withdrew because of adverse events (C = 10; P = 6). Also, 95.9% of the C group and 48.7% of the P group experienced sensations of warmth locally. Pruritus was mentioned in 45.9% of the C group and 31.6% of the P group. |
| Stam et al 20 |
RCT with two groups (no placebo). Randomization was performed using RCODE software (version 3.4) in blocks of 4; period: 7 days |
One hundred sixty-one subjects who were randomly allocated to either group. Six subjects were lost to follow-up (SLR = 2; CCC = 4). Twenty-one subjects met all per protocol criteria. Inclusion criteria: 18–65 years old, acute attack of LBP within previous 72 h, free from back pain during the previous 3 mos, at least moderately painful limitation of movement on physical examination. Exclusion criteria: radicular symptoms, pain above T12, rheumatoid arthritis, ankylosing spondylitis, known hypersensitivity to treatment compounds, use of analgesics other than paracetamol during the treatment period, use of NSAIDs during the treatment period, receiving other treatment for acute LBP, pregnancy, more than 96 h elapsed since onset of pain, including washout for analgesic and/or NSAIDs. |
Spiroflor SLR homeopathic gel (SLR) group (n = 83) or a CCC FNA, the capsici oleoresin gel, (CCC) group (n = 78). Each of the gels was applied at 3 g per day. |
Primary outcome: reduction in VAS scores for pain (100-mm scale) and the proportion of treatment success (a VAS reduction of ≥ 80%). Secondary outcome measures: Proportion of subjects using paracetamol, number of nights with disturbed sleep, duration of absence from work and overall assessments of treatment efficacy/usefulness by the general practitioners and patients. |
Adverse events: Approximately 12% of SLR and 26% of the CCC group experienced an adverse event. Adverse drug reactions were reported by 4% of the SLR group and 24% of the CCC group. A total of four adverse drug reactions in the CCC group and none in the SLR group were considered ''severe''. A total of eight patients in CCC group and 0 in the SLR group withdrew due to adverse drug reactions. |
| Chrubasik et al 17 |
RCT with two groups. Patients were placed in groups by random number allocation; period: 4 wk |
Patients were allocated to a Harpagophytum (H) group (n = 59) and a placebo (P) group (n = 59); 109 completed the trial (H, N = 54; P, N = 55). Inclusion criteria: 18–75 years old, ≥6 mos of LBP not attributable to identifiable causes, suffering from acute increases in pain, and expecting to require ≥4 wk of symptomatic treatment. Exclusion criteria: participation in other clinical studies concurrently or in past 30 days, pregnancy, lactation, insufficient contraception, difficulties with language or cooperation, known allergy to proposed trial medication, history of drug or alcohol abuse, requirement of psychotherapeutic agents, or a serious organic illness affecting any of the organ systems. |
Oral form of Harpagophytum procubens (devil's claw) standardized to a dosage of 50 mg harpagoside per day or 2400 mg of the crude extract. Matched placebo. |
Primary: cumulative requirement for Tramadol (an oral opiate-based analgesic) over the last 3 wk of the study period. Secondary: Number of pain-free patients based on a 5-point visual rating scale and the Arhus LBP index. |
Adverse events: four adverse effects occurred in the Harpagophytum group with only two of these potentially being due to the treatment (i.e., repeated coughs and tachycardia). Ten adverse events occurred in the placebo group. |
| Chrubasik et al 29 |
RCT with three groups; period: 4 wk |
Patients allocated to Harpagophytum at 600 mg (n = 65), or 1200 mg (n = 66) or matched placebo (n = 66). Inclusion criteria: 18–75 years of age, 6 mos of nonspecific LBP, a current exacerbation of their complaint that was affecting both rest and movement and giving rise to pain >5 on a 1–10 VAS and was expected to require ≥4 wk of symptomatic treatment. Exclusion criteria: current or recent participation in any other clinical study, serious organic illness affecting any organ system, a history of drug or alcohol abuse or requirement for psychotherapeutic agents, pregnancy (actual or possible), or lactation, known allergy to any the proposed trial medications, difficulties with language or anticipated cooperation. |
Harpagophytum extract WS 1531 600 mg (50 mg harpagoside), 1200 mg (100 mg harpagoside). |
Primary outcome: proportion of pain-free patients without Tramadol for ≥5 days during the last week of treatment. Secondary outcomes: Arhus index, percentage requiring Tramadol, verbal pain ratings. |
Adverse events: Eight adverse events occurred in the Harpagophytum groups, all being mild gastrointestinal upset (four in each dose group). One adverse event was reported in the placebo group. |
| Chrubasik et al 28 |
RCT with three groups. No report of randomization method; period: 4 wk |
Patients were recruited from the Haifa area in Israel between May and November. Two hundred ten patients were randomized into three groups (n = 70 in each group); 191 completed the trial (placebo, n = 59; 120 mg, n = 67; 240 mg, n = 65). Inclusion criteria: 18–75 years of age, ≥6 mos of intermittent LBP that was not attributable to identifiable causes, a current exacerbation of their complaint at rest and with movement that caused pain of ≥5 of 10 on a VAS and that was expected to require ≥4 wk of treatment. Exclusion criteria: participation in other clinical studies concurrently or in past 30 days, pregnancy, lactation, insufficient contraception, difficulties with language or cooperation, known allergy to proposed trial medication, history of drug or alcohol abuse, requirement of psychotherapeutic agents. |
Extract of dry willow bark (Salix alba): 120 mg salicin, 240 mg salicin. Matched placebo. |
Primary outcome: proportion of patients who responded to treatment by being pain free without Tramadol for ≥5 days during the last week of treatment. Secondary outcome: Arhus LBP index scores |
Adverse events: one adverse reaction (exanthem, swollen eyes, pruritus) could be attributed to the 120-mg willow bark extract group. Two patients in the 240-mg group reported short-lasting adverse events (dizziness attributed to Tramadol, dizziness and fatigue). These patients dropped out for seemingly unrelated reasons. Six adverse events were reported in the placebo group, including three attributable to Tramadol (dizziness/headache, dizziness/vomiting/diarrhea, dry mouth) and the three others reported mild abdominal pain, two of whom dropped out on the first day of the trial. |
| Chrubasik et al 30 |
Open RCT with two groups comparing an herbal medicine (Salix alba) with a synthetic anti-rheumatic (rofecoxib); period: 4 wk |
Two groups (n = 114 per group). Inclusion criteria: age 18–80 yrs, ≥6 mos nonspecific LBP. Exclusion criteria: recent trauma, a history of cancer or risk factors for spinal infection, unexplained weight loss or recent fever or chills, pain exacerbated by being supine or severe nocturnal pain, perineal anesthesia, recent onset of bladder dysfunction or severe progressive neurological deficit in the lower extremity, recent participation in other clinical trial, serious organic illness affecting any organ system, a history of drug or alcohol abuse or requirement for psychotherapeutic drugs, pregnancy or lactation, known allergy to salicylates, difficulties with language or expected cooperation. |
A proprietary extract of Salix alba called Assalix at four capsules per day providing a total of 240 mg of salicin per day, or a single 12.5-mg tablet of rofecoxib per day. |
Pain on a VAS, modified Arhus index, its pain component and the total pain index, physician- and patient-rated success and the acceptability of the treatment on a verbal scale (very good, good, moderate, poor). |
Adverse events: twenty-three in the Salix alba group (13 of gastrointestinal origin, 5 cutaneous allergy, remaining undefined) and 27 in the rofecoxib group (17 GI effects, 1 asthma, rest undefined). GI adverse events were judged as more severe and caused more withdrawals in the rofecoxib group. |
| Chrubasik et al 31 |
RCT with two groups; period: 6 wk |
Subjects allocated to Harpagophytum procumbens (n = 44) group or rofecoxib (n = 44) group. Inclusion criteria: age 45–75 yrs, ≥6 mos of nonspecific LBP, current exacerbation of complaints for 8 wk that was affecting both rest and movement, causing pain of ≥5 of 10 on a VAS and judged to require symptomatic treatment for 6 wk. Exclusion criteria: red flags for LBP, participation in any other clinical study within the last 30 days, serious organic illness affecting any organ system, a history of drug or alcohol abuse or requirement of psychotherapeutic drugs, pregnancy or lactation, known allergies to trial medication, and anticipated difficulties with language or cooperation. |
H. procumbens in a proprietary aqueous extract called Doloteffin (standardized to contain 60 mg harpagoside) or 12.5 mg rofecoxib (Vioxx) per day. |
Primary outcome: Proportion of patients who recorded ''no pain'' without using Tramadol for ≥5 days in the final week or treatment. Secondary and other outcomes: Proportion of patients in whom the averaged daily pain scores in the 6th wk had decreased by 20%–50% of the average in the first week; the percentage change from baseline of a modified Arhus LBP index; the percentage change from baseline on the Health Assessment Questionnaire; Tramadol requirement. |
Adverse effects: fourteen participants in each group. GI: 8 in the devil's claw group, 9 in the Vioxx group that tended to be more severe. Two serious adverse events occurred in the devil's claw group but were judged as being unrelated to the study medication. Circulatory and laboratory variables were not affected by either treatment. |
| Krivoy et al 18 |
Thirty-five subjects randomized to two groups and a further 16 acted as controls; period: 4 wk |
Nineteen subjects in the Salix alba group, 16 in a placebo group, and 16 in an acetylsalicylate group. Inclusion criteria: acute exacerbations of chronic LBP, stable ischemic heart disease. Exclusion criteria: NSAID use. |
786.48 mg twice per day of an ethanol extract of the bark of Salix daphnoides (240-mg salicin content per day), matched placebo, or 100 mg acetylsalicylate. |
Primary outcome: Platelet aggregation. |
Adverse events: none reported. |
| Chrubasik et al 34 |
RCT with two groups. Participants were placed in groups by computerized randomization list; period: 3 wk |
Two hundred and eighty-two participants were allocated to Finalgon CPD Wärmecreme (a capsicumcontaining cream) (n = 140), or matched placebo (n = 141). Inclusion criteria: 18–65 yrs old, Caucasian, chronic pain of the soft tissues of the musculoskeletal apparatus, subjective pain at enrollment ≥5 (VAS 0–10; 0, no pain; 10, intolerable pain), ability and expressed willingness of the patient to follow the investigator's instructions, i.e., meeting the prerequisites of the study, applying study medication according to the dosage regimen and filling in the questionnaires at the control visits, and granting of written informed consent. Exclusion criteria: severe comorbidity, addiction to alcohol or other drugs, pregnancy and lactation, insufficient contraceptive protection, participation in another clinical trial within the last 4 wk, concomitant psychiatric disorders, a surgical procedure required in the immediate future, inability of the patient to understand the nature, importance and consequences of the study, muscle rupture, vertebral disk prolapse, spondylolisthesis, spinal canal stenosis, known or clinically proven instability of the spine, spinal fractures, tumors, infections, inflammatory joint conditions, seronegative spondyloarthropathies, osteoporosis as the cause of pain, chronic skin diseases, known hypersensitivity to capsaicin or other ingredients of the cream, anxiety or depressive conditions, ≥11 points of anxiety or depression scores (Hamilton Anxiety Depression Scale). |
'Finalgon CPD Wärmecreme' of which 100 g contained 2.2–2.6 g soft extract of Capsici fructus acer corresponding to 53 mg capsaicin (0.05%), applied as a thin layer thrice daily over a 3 wk period. |
Primary outcome: Treatment response, defined as pain sum score reduction ≥30%. Secondary outcomes: Median relative pain sum score improvement, average pain in the last 24 h, worst pain in the last 3 days, average pain in the last 3 days, pain intensity at the moment of maximum pain relief, the delay between the application of cream and the onset of maximum effect, the duration of analgesia, efficacy as determined by the investigator (excellent, good, adequate, unsatisfactory) and patient (free of complaints, symptoms improved, unchanged, worsened). |
Adverse effects: three patients in the treatment group experienced adverse effects and none in the placebo group. Events included unpleasant local heat sensation in two participants and pruritus in one participant. |
| da Silva et al 35 |
RCT with two groups; period: 15 days |
Twenty participants allocated to Brazilian arnica gel (n = 10) or placebo gel (n = 10). Inclusion criteria: No specific criteria listed. Patient recruitment was based on spontaneous demand for treating lumbago within the academic community at UVV/ES and was accompanied by the physiotherapy clinic. All participants went through a screening process coordinated by the physiotherapist responsible for the orthopedics, traumatology, and rheumatology sector of the clinic. After screening, participants were submitted to medical evaluations to diagnose the nature of their lumbago before being allowed to participate in the research program. Exclusion criteria: age under 18 yrs except with permission of parent or legal guardian, people who were not otherwise in good physical and/or mental condition, who did not pass the screening process, who were eliminated as a result of diagnoses made by the physiotherapy sector, and pregnant women. |
Concentrated plant extract (5%) from aerial vegetative and reproductive parts of S. chilensis Meyen, diluted in propylene glycol and added at a proportion of 5% (w/v) in carbomer gel, corresponding to active substances in 5 g of dry raw material. Ten grams of the placebo or arnica gels was manually and uniformly applied on the area of the lesion twice daily. |
Primary outcome: Change in perception of pain by VAS. Secondary outcome: Lumbar flexibility, as determined by the modified Schober method. |
Adverse effects: none reported. |
| Giannetti et al 36 |
RCT with two groups; period: 5 days |
Patients allocated to Kytta-Salbe (a cream containing Comfrey root extract) (n = 60) or a matched placebo cream (n = 60). Inclusion criteria: Age 18–60 yrs, good general condition, written informed consent, acute back pain (either upper or lower back pain) not in combination, sensitivity to algometric pressure on the site contralateral to the painful trigger point ≥2.5 N/cm2, basic value of the pressure algometry on the trigger point shall not exceed 50% of the respective value of the site contralateral to the painful trigger point. Exclusion criteria: upper or lower back pain attributable to any identifiable cause, any recent trauma, any recent strains of the back muscles documented by clinical evaluation and anamnesis, chronic back pain, diabetes mellitus, risk factors for spinal infection, recent onset of bladder dysfunction or severe or progressive neurological deficit in the low extremity (as a possible indication of prolapsed disc), concomitant use of any anti-inflammatory drugs, heparinoids or analgesics, including herbal preparations (glucocorticosteroids, NSAIDs, etc.) for the same indication or other indications (e.g., rheumatoid arthritis), analgesics or NSAIDs applied by any route of administration within 10 days of study entry or corticoid drugs applied by any route of administration within 60 days of study entry, any other concomitant treatment or medication that interferes with the conduct of the trial, known intolerance or hypersensitivity (allergy) to trial treatments, including known toxic reactions, local skin infections that do not allow the application of the test ointment, participation in a clinical trial within the previous 30 days before enrollment in the trial, participation in this study before or simultaneous participation in another clinical trial, pregnancy or lactation period, women with childbearing potential without an effective contraceptive method, abuse of alcohol, medicaments or illicit drugs, any patient not considered suitable for enrollment by investigator, legal incapacity or limited legal capacity to give informed consent |
Kytta-Salbe f. 100 g contains 35 g 99% PA reduced Rad symphyti fluid extract. Four grams were applied topically, administered 3 times a day at intervals of approximately 8 h and continued for 5 days. |
Primary outcome: AUC of the VAS values on active standardized movement. Secondary outcomes: AUC of back pain at rest by VAS, AUC over 5 days of pressure algometry values, global assessment of efficacy by the patients, global assessment of efficacy by the investigators. |
Adverse effects: four participants in the treatment group and three in the placebo group experienced adverse effects. In the treatment group, two participants experienced headaches and one participant experienced pruritus. In the control group, participants experienced eczema, cold, nausea, and rhinitis. |
| Yip and Tse37 |
Unblinded RCT with two groups; period: 3 wk |
Sixty-one patients were allocated to acupressure with lavender oil (n = 32) or conventional treatment (n = 29). Inclusion criteria: ≥18 years with nonspecific subacute LBP for most days in the last 4 wk; who had not received acupuncture, physiotherapy, or manipulative therapy in the past week; who could understand the explanation of the study, complete the interview and comprehend the instructions. Nonspecific sub-acute LBP was defined as pain on most days in the last 4 wk, in the area between the lower coastal margins and the gluteal folds without known specific cause, such as a spinal deformity. Exclusion criteria: LBP caused by specific entities, such as infection, metastases, neoplasm osteoporosis, fractures, spine deformity, or prolapsed intervertebral disc; had undergone surgery or had dislocation, fracture, neurological deficits, spinal disease, varicose vein, blood dyscrasia, cancer or systemic disorders; were pregnant; were allergic to natural lavender aromatic oil; had a wound at any of the acupoints at the back or on the lower limb; or had had a surgical intervention within the last 3 mos. |
Acupoint stimulation with a digital electronic muscle stimulator for 10 min, followed by acupressure massage, consisting of the application of a light to medium finger press with 3% aromatic natural lavender oil with grape seed oil as the base on 8 fixed acupoints for 2 min each. Treatment lasted 35–40 min and occurred 8 times over a 3-wk period. |
Primary outcome: Pain intensity rating on VAS. Secondary outcomes: Range of motion of lateral spine flexion, quantified by lateral fingertip-to-ground distance, walking time for 15 meters, interference with daily activities measured by the modified Aberdeen LBP scale. |
Adverse effects: Reported no adverse effects. |
