Lavender oil preparation Silexan is effective in mild-to-moderate major depression: a randomized, placebo- and reference-controlled trial.

Anxiety and depressive disorders have overlapping symptoms and share common neurobiological pathways. Antidepressant drugs have been demonstrated to be efficacious in anxiety as well. Vice versa, it may also be promising to investigate the efficacy of anxiolytic drugs such as silexan in major depressive disorder (MDD). Patients with a mild or moderate, single or recurrent episode of MDD and a total score of 19-34 points on the Montgomery Åsberg Depression Rating Scale (MADRS) were randomized to receive 1 × 80 mg/d silexan, 1 × 50 mg/d sertraline, or placebo double-blind, double-dummy for 56 days. The primary outcome measure was the MADRS total score change between baseline and treatment end. Treatment groups were compared using a treatment policy estimand. 498 subjects (silexan 170, sertraline 171, placebo 157) were treated and analyzed. After 8 weeks, silexan and sertraline were superior to placebo for MADRS total score reduction, with absolute differences to placebo of 2.17 (95% confidence interval: 0.58; 3.76) points and 2.59 (1.02; 4.17) points, respectively (p < 0.01). Moreover, silexan was superior to placebo for alleviation of functional impairment according to the Sheehan Disability Scale with a difference of 2.40 (1.04; 3.76) points (p < 0.001). Both treatments were well tolerated; eructation was the most frequent adverse effect of silexan. The study confirms the antidepressant efficacy of silexan in mild or moderate MDD, including significant improvements in the subjects' functional capacity. The results for sertraline confirm the assay sensitivity of the trial. Both drugs were well tolerated.Trial registrationEudraCT2020-000688-22 first entered on 12/08/2020.

Baseline symptom severity and efficacy of Silexan in patients with anxiety disorders: A symptom-based, patient-level analysis of randomized, placebo-controlled trials.

The influence of baseline severity on the efficacy of Silexan, a proprietary essential oil from Lavandula angustifolia, in anxiety disorders has not been investigated in a pooled dataset. We report on an individual patient data analysis of all five double-blind, randomized, placebo-controlled trials with Silexan in anxiety disorders. Eligible participants received Silexan 80 mg/d or placebo for 10 weeks. Analyses were based on the Hamilton Anxiety Rating Scale (HAMA), its psychic and somatic anxiety subscores, and the Clinical Global Impressions (CGI) scale. To correlate baseline severity with outcome, patients were segregated into mild, moderate, and severe cases. Altogether 1,172 patients (Silexan, n = 587; placebo, n = 585) were analyzed. For the HAMA total score, we found a significant association between the score at baseline and the treatment effect of Silexan versus placebo at week 10 (p < 0.001). HAMA items from the somatic domain scored lower at baseline and showed less improvement than items from the psychic domain, particularly in patients with mild or moderate baseline symptoms. For CGI item 2 (global improvement), significant efficacy favoring Silexan were observed in mild, moderate, and severe baseline symptom severity. Although significant improvements were found for all subsets, the more severe the initial symptoms, the greater the treatment effects documented by the HAMA. Overall this analysis confirms that Silexan is an effective treatment option in early or mild stages of anxiety disorder. Given its favorable safety profile, Silexan can thus fill a therapeutic gap in the treatment of (subsyndromal) anxiety disorders.

Efficacy of Silexan in patients with anxiety disorders: a meta-analysis of randomized, placebo-controlled trials.

INTRODUCTION: We report on a meta-analysis of Silexan, a proprietary active substance produced from Lavandula angustifolia, in subthreshold anxiety, mixed anxiety and depressive disorder (MADD), and generalized anxiety disorder (GAD). METHODS: The present analyses are based on all currently completed 5 double-blind, randomized, placebo-controlled trials investigating Silexan in adult out-patients who received Silexan 1 × 80 mg/day or placebo for ten weeks according to random assignment (n = 1213). Efficacy was assessed based on the Hamilton Anxiety Rating Scale (HAMA), several anxiety self-rating scales, the Clinical Global Impression (CGI) scale, and the Short Form-36 (SF-36) health status questionnaire. RESULTS: After ten weeks' treatment, Silexan was significantly superior to placebo in reducing the HAMA total score (including the psychic and somatic anxiety sub-scores) and self-rated anxiety. Based on a ≥ 50% HAMA total score reduction, the responder rate ratio was 1.34 favoring Silexan, and the rate ratio of subjects much or very much improved according to the CGI was 1.51. Silexan was also significantly superior in improving the physical and mental health summary scores of the SF-36. There were no significant between-group differences concerning the occurrence of adverse events (AEs), serious AEs, and premature withdrawal due to AEs. CONCLUSIONS: This meta-analysis demonstrates that Silexan exerts significant anxiolytic effects in subthreshold anxiety, GAD and MADD that were consistently reflected in investigator ratings and patient-reported outcomes, including improvement of health-related life-quality, while showing favorable tolerability and safety.

No Abuse Potential of Silexan in Healthy Recreational Drug Users: A Randomized Controlled Trial.

BACKGROUND: Silexan is a lavender essential oil with established anxiolytic and calming efficacy. Here we asked whether there is a potential for abuse in human patients. METHODS: We carried out a phase I abuse liability single-center, double-blind, 5-way crossover study in healthy users of recreational central nervous system depressants. They received single oral doses of 80 mg (therapeutic dose) and 640 mg Silexan, 2 mg and 4 mg lorazepam (active control) and placebo in randomized order, with 4- to 14-day washout periods between treatments. Pharmacodynamic measures included validated visual analogue scales assessing positive, negative, and sedative drug effects and balance of effects; a short form of the Addiction Research Center Inventory; and a drug similarity assessment. The primary outcome measure was the individual maximum value on the drug liking visual analogue scale during 24 hours post-dose. RESULTS: Forty participants were randomized and 34 were evaluable for pharmacodynamic outcomes. In intraindividual head-to-head comparisons of the drug liking visual analogue scale maximum value, both doses of Silexan were rated similar to placebo whereas differences were observed between Silexan and lorazepam and between placebo and lorazepam (P < .001). These data were supported by all secondary measures of positive drug effects and of balance of effects. Differences between placebo and both doses of Silexan were always negligible in magnitude. Moreover, Silexan showed no sedative effects and was not perceived to be similar to commonly used drugs that participants had used in the past. CONCLUSIONS: Silexan did not exhibit any abuse potential in a standard abuse potential detection screen study and is unlikely to be recreationally abused.

Beneficial effects of Silexan on sleep are mediated by its anxiolytic effect.

Disturbed sleep is among the most prevalent hyperarousal symptoms in anxiety disorders. Most drugs recommended for anxiety and insomnia have a sedating effect which is related to their beneficial effect on disturbed sleep. Silexan is a proprietary essential oil from Lavandula angustifolia. This drug has significant anxiolytic and sleep improving properties. Interestingly, these effects are not associated with sedation. Here we asked whether the positive effects on sleep are due to primary pharmacodynamic or secondary, disease related effects. We used the data from a double-blind, randomized study in which 212 patients were analyzed for efficacy after ten weeks' treatment with 80 mg/day Silexan or placebo. Anxiety and disturbed sleep were assessed using the Hamilton Anxiety Scale (HAMA) and the Pittsburgh Sleep Quality Index (PSQI), respectively. Regression-based mediation analysis was employed to estimate direct treatment effects and indirect effects mediated by anxiety control separately for each study group. Sobel's test was used to investigate the extent to which the mediator (HAMA change) contributes to the total effect of the independent variable (treatment) on the dependent variable (PSQI change). Compared to placebo, Silexan significantly reduced the total scores of the HAMA (p < 0.001) and of the PSQI (p = 0.002) after ten weeks, with clinically meaningful treatment group differences that were observed already after two and six weeks for HAMA and PSQI, respectively. Silexan had a statistically meaningful indirect effect on sleep (mediated by the effect on anxiety; p < 0.001) but no appreciable direct effect (p = 0.958). The ratio between the indirect and the total effect was determined to be 0.984, i. e., 98.4% of the total effect of Silexan on disturbed sleep were explained by the effect of Silexan on the symptoms of anxiety whereas 1.6% were attributable to a direct effect. The results indicate that Silexan exerts a secondary sleep improving effect almost exclusively through its anxiolytic action rather than by sedation. Findings are consistent with the drug's assumed mechanism of action.

Efficacy of Silexan in subthreshold anxiety: meta-analysis of randomised, placebo-controlled trials.

Subthreshold psychiatric disorders do not fully meet the diagnostic criteria of syndromal disorders but may be associated with comparable disability. To investigate the anxiolytic effect of Silexan, an active substance from lavender oil for oral administration, in patients with subthreshold anxiety, a meta-analysis that included all published trials with Silexan in this indication was performed. Three randomised, placebo-controlled trials in subthreshold anxiety disorders (anxiety disorder not otherwise specified, restlessness and agitation, mixed anxiety and depressive disorder) were included. Eligible participants with a baseline Hamilton Anxiety Rating Scale (HAMA) total score ≥ 18 points received 1 × 80 mg/day Silexan or placebo for 10 weeks. Outcomes included the HAMA, the Pittsburgh Sleep Quality Index, the Zung Self-rating Anxiety Scale, the Clinical Global Impressions questionnaire and the SF-36 health status inventory. Data were analysed using meta-analysis based on pooled raw data of individual patients (random effects models). A total of 697 patients were assessed for efficacy. Silexan was superior to placebo in reducing the HAMA total score during 10 weeks' treatment [mean value difference, 95% confidence interval: 3.83 (1.28; 6.37) points]. Superiority was comparably pronounced for psychic and somatic anxiety as well as for observer- and self-rated anxiety. Silexan had a beneficial effect on sleep (secondary to the anxiolytic effect) without causing sedation and improved the patients' health-related quality of life. Adverse event incidence in both treatment groups was comparable [risk ratio: 1.06 (0.85; 1.33)]. Silexan has a significant and clinically meaningful anxiolytic effect in subthreshold anxiety. The results cannot be generalised to other lavender oil products.

Silexan in generalized anxiety disorder: investigation of the therapeutic dosage range in a pooled data set.

Silexan, a special active substance produced from Lavandula angustifolia, is efficacious in subsyndromal anxiety at a dose of 80 mg/day, but its effective dosage in generalized anxiety disorder (GAD) has yet to be defined. In two double-blind, placebo-controlled trials, daily doses of 10, 40, 80, and 160 mg silexan were administered for 10 weeks. A total of 925 adults with GAD according to Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria and a Hamilton Anxiety Scale (HAMA) total score of at least 18 points were analyzed for efficacy. We assessed the change versus baseline for the HAMA and the Covi Anxiety Scale, the Clinical Global Impressions scale, the Sheehan Disability Scale, and the SF-36 health status questionnaire using analysis of variance and covariance. Silexan 160 mg/day was superior to placebo for all efficacy outcomes investigated, with responder rates exceeding 60% on the basis of HAMA and Clinical Global Impressions criteria. For the 80 mg/day dosage, superiority over placebo could be shown in one trial as well as in the pooled analysis. The risk of adverse events under silexan was similar to placebo for all dosages investigated. In GAD silexan 160 mg/day is efficacious whereas 80 mg/day may represent the lower end of the therapeutic range. Daily doses up to 160 mg were well tolerated.

Efficacy of Silexan in mixed anxiety-depression--A randomized, placebo-controlled trial.

Mixed anxiety and depressive disorder (MADD; ICD-10 F41.2) is a condition characterized by subsyndromal symptoms of anxiety and depression, neither of which are clearly predominant. Silexan has been demonstrated to be efficacious in subsyndromal and syndromal anxiety disorders and co-morbid depressive symptoms. In this study 318 adult out-patients with MADD according to ICD-10 criteria, a total score ≥18 points on the Hamilton Anxiety Rating Scale (HAMA), and at least moderately severe anxious and depressed mood were randomized and received 1×80mg Silexan or placebo in double-blind fashion for a scheduled period of 70 days. Primary outcome measures were the HAMA and Montgomery Åsberg Depression Rating Scale (MADRS) total score changes between baseline and treatment end. The HAMA total score decreased by 10.8±9.6 points for Silexan and by 8.4±8.9 points for placebo (treatment group difference: p<0.01, one-sided; ANCOVA with factors for treatment and centre and the baseline value as covariate), and total score decreases of 9.2±9.9 and 6.1±7.6 points, respectively, were observed for the MADRS (p<0.001). Compared to placebo, the patients treated with Silexan had a better over-all clinical outcome and showed more pronounced improvements of impaired daily living skills and health related quality of life. Eructation was the only adverse event with a substantially higher incidence under Silexan. The study thus demonstrates that Silexan is efficacious and safe in the treatment of MADD.

No interacting influence of lavender oil preparation silexan on oral contraception using an ethinyl estradiol/levonorgestrel combination.

PURPOSE: Silexan is an oral Lavender oil preparation with proven anxiolytic efficacy. Given the high prevalence of anxiety and restlessness in younger women, oral contraceptives and Silexan will likely be co-administered. METHODS: A double-blind, randomised, 2-period crossover study was performed to investigate the effects of Silexan on the pharmacokinetics and pharmacodynamics of Microgynon(®), a combination oral contraceptive containing ethinyl estradiol 0.03 mg (EE) and levonorgestrel 0.15 mg (LNG) in healthy, fertile, adult females. During 2 consecutive cycles of 28 days, oral contraception was given for 21 days combined with 1 × 160 mg/day Silexan or placebo. Plasma concentration-time profiles of EE and LNG were obtained on day 18 ± 1 up to 24 h after dosing. The primary outcome measure was the area under the concentration-time curve over a dosing interval of τ = 24 h (AUCτ) for EE and LNG plasma levels. An interaction with Silexan was formally excluded if the 90 % confidence interval for the AUCτ ratio during co-administration with Silexan or placebo was included within the range of 0.80-1.25. Secondary outcomes included EE and LNG peak concentration (C max) and time to C max (t max), follicle size, endometrial thickness, the Hoogland score, and serum levels of estradiol, progesterone, and sex hormone-binding globulin. RESULTS: A total of 24 women (mean age 27.3 years; mean body mass index 22.2 kg/m(2)) participated. The confidence intervals for the EE and LNG AUCτ and C max ratios fell within the pre-specified limits, indicating no interaction (point estimates [Silexan/placebo] AUCτ EE 0.97, LNG 0.94; C max EE 0.99, LNG 0.96). For LNG, t max was slightly delayed. No secondary outcome indicated any impairment of contraceptive efficacy. CONCLUSIONS: Co-administration of Silexan did not affect the efficacy of a combination oral contraceptive containing EE and LNG and was well tolerated.

Fixed-dose combination PRO 160/120 of sabal and urtica extracts improves nocturia in men with LUTS suggestive of BPH: re-evaluation of four controlled clinical studies.

PURPOSE: To determine the effects of the herbal fixed-dose combination PRO 160/120 (extracts from saw palmetto fruits and stinging nettle roots) on nocturnal voiding frequency, as measured by question 7 of the IPSS questionnaire, in patients with moderate-to-severe LUTS/BPH after 24 weeks of treatment compared to placebo, to the α-blocker tamsulosin, or to the 5α-reductase inhibitor finasteride. METHODS: The study is about post hoc evaluation of four published randomized, double-blind clinical trials on PRO 160/120, two compared with placebo, one with finasteride and one with tamsulosin. In addition, a pooled data analysis of the two placebo-controlled trials was conducted. RESULTS: We analyzed data from a total of 922 patients with a mean age of 66 years and a mean baseline nocturnal voiding frequency of 2.1. In the pooled analysis of placebo-controlled trials, nocturnal voids improved by 0.8 (29 %) with PRO 160/120 compared to 0.6 (18 %) with placebo (p = 0.015, Wilcoxon test, one-tailed). The 69 % responder rate to PRO 160/120 was significantly superior to the placebo response (52 %; p = 0.003, χ (2)-test, two-tailed). The majority of responders improved by 1 void/night. Absolute improvements and response rates were consistently higher with PRO 160/120 than with placebo over a range of baseline nocturnal voiding frequencies. There were no differences between PRO 160/120 and finasteride or tamsulosin regarding absolute improvement of nocturnal voids or responds rates. CONCLUSION: PRO 160/120 significantly improved nocturnal voiding frequency compared to placebo and similar to tamsulosin or finasteride.

Lavender oil preparation Silexan is effective in generalized anxiety disorder--a randomized, double-blind comparison to placebo and paroxetine.

The anxiolytic efficacy of the orally administered lavender oil preparation Silexan was investigated in generalized anxiety disorder (GAD) in comparison to placebo and paroxetine. In this randomized, double-blind, double-dummy trial 539 adults with GAD according to DSM-5 criteria and a Hamilton Anxiety Scale (HAMA) total score ⩾ 18 points participated and received 160 or 80 mg Silexan, 20 mg paroxetine, or placebo once daily for 10 wk. The primary efficacy endpoint was the HAMA total score reduction between baseline and treatment end. The HAMA total score decreased by 14.1 ± 9.3 points for Silexan 160 mg/d, 12.8 ± 8.7 points for Silexan 80 mg/d, 11.3 ± 8.0 points for paroxetine, and 9.5 ± 9.0 points for placebo (mean ± s.d.). Silexan 160 and 80 mg/d were superior to placebo in reducing the HAMA total score (p < 0.01) whereas paroxetine showed a trend towards significance (p = 0.10) in the full analysis set. The difference between paroxetine and placebo was more pronounced in the analysis of observed cases (HAMA total score reduction: p < 0.01). In the Silexan 160 mg/d group 73/121 patients (60.3%) showed a HAMA total score reduction ⩾ 50% of the baseline value and 56 (46.3%) had a total score <10 points at treatment end, compared to 70/135 (51.9%) and 45 (33.3%) for Silexan 80 mg/d, 57/132 (43.2%) and 45 (34.1%) for paroxetine, and 51/135 (37.8%) and 40 (29.6%) for placebo. In addition, Silexan showed a pronounced antidepressant effect and improved general mental health and health-related quality of life. Incidence densities of adverse events (AEs) were 0.006 AEs/d for Silexan 160 mg/d, 0.008 AEs/d for 80 mg/d, 0.011 AEs/d for paroxetine, and 0.008 AEs/d for placebo. In GAD Silexan is more efficacious than placebo. AE rates for Silexan were comparable to placebo and lower than for the active control paroxetine.

Drug cocktail interaction study on the effect of the orally administered lavender oil preparation silexan on cytochrome P450 enzymes in healthy volunteers.

UNLABELLED: This cocktail study evaluated the interaction potential of the oral lavender oil preparation silexan with major P450 (cytochrome P450) enzymes. SUBJECTS AND METHODS: Sixteen healthy male or female Caucasians completed this double-blind, randomized, 2-fold crossover study. Silexan (160 mg) or placebo were administered once daily for 11 days. Additionally, on day 11 of both study periods, 150 mg caffeine (CYP1A2), 125 mg tolbutamide (CYP2C9), 20 mg omeprazole (CYP2C19), 30 mg dextromethorphan-HBr (CYP2D6), and 2 mg midazolam (CYP3A4) were administered orally. Formal interaction was excluded if the 90% confidence interval (CI) for the silexan over placebo ratios for phenotyping metrics (primary: AUC(0-t)) was within a 0.70-1.43 range. RESULTS: According to the AUC(0-t) comparisons, silexan had no relevant effect on CYP1A2, 2C9, 2D6, and 3A4 activity. Secondary phenotyping metrics confirmed this result. Mean ratios for all omeprazole-derived metrics were close to unity. The 90% CI for the AUC(0-t) ratio of omeprazole but not for omeprazole/5-OH-omeprazole plasma ratio 3 hours post-dose or omeprazole/5-OH-omeprazole AUC(0-t) ratio (secondary CYP2C19 metrics) was above the predefined threshold of 1.43, probably caused by the inherent high variability of omeprazole pharmacokinetics. Silexan and the phenotyping drugs were well tolerated. Repeated silexan (160 mg/day) administration has no clinically relevant inhibitory or inducing effects on the CYP1A2, 2C9, 2C19, 2D6, and 3A4 enzymes in vivo.

Efficacy and safety of silexan, a new, orally administered lavender oil preparation, in subthreshold anxiety disorder - evidence from clinical trials.

We review the data on the efficacy and tolerability of silexan, a novel preparation from lavender oil for oral use, in the treatment of anxiety disorders and related condition with particular attention to subthreshold generalized anxiety disorder (GAD). Three randomized, double-blind clinical trials were identified which investigated the efficacy of silexan in subsynromal anxiety disorder (vs. placebo; 10 weeks' treatment), in GAD (vs. lorazepam; 6 weeks), and in restlessness and agitation (vs. placebo; 10 weeks) according to DSM-IV and ICD-10 criteria. All trials assessed the participants' anxiety levels using the Hamilton Anxiety Scale (HAMA). Across all trials 280 patients were exposed to silexan 80 mg/day, 37 were treated with lorazepam 0.5 mg/day and 192 received placebo. Average within group HAMA total scores at baseline ranged between 24.7 and 27.1 points. Patients treated with silexan showed average HAMA total score decreases by between 10.4 ± 7.1 and 12.0 ± 7.2 points at week 6 and by between 11.8 ± 7.7 and 16.0 ± 8.3 points at week 10. In GAD silexan and lorazepam showed comparable HAMA total score reductions (90% CI for mean value difference: -2.3; 2.8 points).

Silexan, an orally administered Lavandula oil preparation, is effective in the treatment of 'subsyndromal' anxiety disorder: a randomized, double-blind, placebo controlled trial.

This study was performed to investigate the anxiolytic efficacy of silexan, a new oral lavender oil capsule preparation, in comparison to placebo in primary care. In 27 general and psychiatric practices 221 adults suffering from anxiety disorder not otherwise specified (Diagnostic and Statistical Manual of Mental disorders-IV 300.00 or International Statistical Classification of Diseases and Related Health Problems, Tenth revision F41.9) were randomized to 80 mg/day of a defined, orally administered preparation from Lavandula species or placebo for 10 weeks with visits every 2 weeks. A Hamilton Anxiety Scale (HAMA) total score >or=18 and a total score >5 for the Pittsburgh Sleep Quality Index (PSQI) were required. The primary outcome measures were HAMA and PSQI total score decrease between baseline and week 10. Secondary efficacy measures included the Clinical Global Impressions scale, the Zung Self-rating Anxiety Scale, and the SF-36 Health Survey Questionnaire. Patients treated with silexan showed a total score decrease by 16.0+/-8.3 points (mean+/-SD, 59.3%) for the HAMA and by 5.5+/-4.4 points (44.7%) for the PSQI compared to 9.5+/-9.1 (35.4%) and 3.8+/-4.1 points (30.9%) in the placebo group (P<0.01 one-sided, intention to treat). Silexan was superior to placebo regarding the percentage of responders (76.9 vs. 49.1%, P<0.001) and remitters (60.6 vs. 42.6%, P=0.009). Lavandula oil preparation had a significant beneficial influence on quality and duration of sleep and improved general mental and physical health without causing any unwanted sedative or other drug specific effects. Lavandula oil preparation silexan is both efficacious and safe for the relief of anxiety disorder not otherwise specified. It has a clinically meaningful anxiolytic effect and alleviates anxiety related disturbed sleep.

Efficacy and safety of a combination of Sabal and Urtica extract in lower urinary tract symptoms--long-term follow-up of a placebo-controlled, double-blind, multicenter trial.

In an open-label extension of a randomized, double-blind clinical trial, the long-term efficacy and tolerability of a fixed combination of 160 mg Sabal fruit extract WS 1473 and 120 mg Urtica root extract WS 1031 per capsule (PRO 160/120) were investigated in elderly men with moderate or severe lower urinary tract symptoms (LUTS) caused by benign prostatic hyperplasia (BPH). Two hundred and fifty-seven patients were randomly treated with 2 x 1 capsule/day PRO 160/120 or placebo for 24 weeks, followed by a 24-week control period and a 48-week follow-up period in which all patients received PRO 160/120. Efficacy measures included the assessment of LUTS [International Prostate Symptom Score ((I-PSS) self-rating questionnaire] and uroflow and sonographic parameters. Two hundred and nineteen subjects participated in the follow-up. Between baseline and end of observation (week 96) the I-PSS total score was reduced by 53% (P < 0.001), peak and average urinary flow increased by 19% (P < 0.001), and residual urine volume decreased by 44% (P = 0.03). The incidence of adverse events during follow-up was one in 1,181 treatment days; in only one event a causal relationship with intake of PRO 160/120 could not be excluded. Treatment with PRO 160/120 thus provides a clinically relevant benefit over a period of 96 weeks.

Efficacy and safety of a combination of sabal and urtica extract in lower urinary tract symptoms. A randomized, double-blind study versus tamsulosin.

The aim of this prospective, randomized, double-blind, double-dummy, multicenter clinical trial was to investigate the efficacy and safety of PRO 160/120 (Prostagutt forte), a fixed combination preparation of 160 mg Sabal fruit extract WS 1473 and 120 mg Urtica root extract WS 1031 per capsule, in comparison to the alpha1-adrenoceptor antagonist tamsulosin (CAS 106463-17-6) in lower urinary tract symptoms (LUTS) caused by benign prostatic hyperplasia (BPH). 140 elderly out-patients suffering from LUTS caused by BPH, with an initial score > or = 13 points in the International Prostate Symptom Score (I-PSS), received 2 x 1 capsule/d PRO 160/120 or 1 x 0.4 mg/d tamsulosin and were treated for 60 weeks with interim visits at weeks 8, 16, 24, 36, and 48. The primary outcome measure for efficacy was the change in I-PSS total score, the percentage of patients with an I-PSS score < or = 7 points at endpoint ('responders') was analyzed as well. During 60 weeks of randomized treatment the I-PSS total score was reduced by a median of 9 points in both groups. In total, 32.4 % of the patients in the PRO 160/120 group and 27.9% in the tamsulosin group were responders (test for non-inferiority of PRO 160/120: p = 0.034; non-inferiority margin 10%). Both drugs were well tolerated, with one adverse event in 1514 treatment days for PRO 160/120 and one event in 1164 days for tamsulosin. The study supports non-inferiority of PRO 160/120 in comparison to tamsulosin in the treatment of LUTS caused by BPH.