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Biomedical subjects

M H Pittler

Publications and source records attributed to M H Pittler.

At least 37 records · Page 2Linked to original sources
PubMed2002

Horse chestnut seed extract for chronic venous insufficiency.

BACKGROUND: Conservative therapy of chronic venous insufficiency (CVI) consists largely of compression treatment. However, this often causes discomfort and has been associated with poor compliance, which renders oral drug treatment an attractive option. OBJECTIVES: To review the evidence from rigorous clinical trials assessing the efficacy and safety of oral horse chestnut seed extract (HCSE) versus placebo, or reference therapy for the treatment of CVI. SEARCH STRATEGY: Publications describing randomised controlled trials (RCTs) of HCSE for chronic venous insufficiency were sought through EMBASE, MEDLINE, Amed, and Phytobase (from inception to January 2001), The Cochrane Controlled Trials Register (Issue 1, 2001) and the Specialised Trials Register of the Cochrane Peripheral Vascular Diseases Group (April 2001). Manufacturers of HCSE preparations and experts on the subject were contacted and asked to contribute published and unpublished material. There were no restrictions on the language of publication. SELECTION CRITERIA: Randomised controlled trials of oral HCSE mono-preparations for patients with CVI were included. Trials comparing HCSE with placebo or reference medications were included. Trials assessing HCSE as one of several active components in a combination preparation or as a part of a combination treatment were excluded. DATA COLLECTION AND ANALYSIS: Data were extracted systematically and methodological quality was evaluated using a standard scoring system. The screening of studies, selection, data extraction and the assessment of methodological quality were performed independently by two reviewers. Disagreements concerning evaluation of individual trials were resolved through discussion. MAIN RESULTS: Overall, the included placebo controlled trials suggest an improvement in CVI related signs and symptoms. Leg pain was assessed in six placebo-controlled trials that reported a significant reduction of leg pain in the HCSE groups compared with the placebo groups. One trial, which reported adequate data suggested a weighted mean difference (WMD) of 42.4 mm [95% confidence interval (CI) 34.9-49.9] measured on a 100 mm visual analogue scale. Leg volume was assessed in five placebo-controlled trials. Meta-analysis of four trials (n = 239) reporting adequate data suggested a significant reduction in favour of HCSE compared with placebo (WMD 58.6 ml [95% CI 24.9-92.2]). One trial indicated that HCSE may be as effective as treatment with compression stockings. Adverse effects are usually mild and infrequent. REVIEWER'S CONCLUSIONS: The evidence presented implies that HCSE is an efficacious and safe short-term treatment for CVI. However several caveats exist and more rigorous RCTs are required to assess the efficacy of this treatment option.

Humans↗
PubMed2002

Artichoke leaf extract for treating hypercholesterolaemia.

BACKGROUND: Hypercholesterolaemia is directly associated with an increased risk for coronary heart disease and other sequelae of atherosclerosis. Artichoke leaf extract (ALE), which is available as an over-the-counter remedy, has been implicated in lowering cholesterol levels. Whether ALE is truly efficacious for this indication, however, is still a matter of debate. OBJECTIVES: To assess the evidence of ALE versus placebo or reference medication for treating hypercholesterolaemia defined as mean total cholesterol levels of at least 5.17 mmol/L (200 mg /dL). SEARCH STRATEGY: We searched MEDLINE, Embase, Amed, Cinahl, CISCOM and the Cochrane Controlled Trial Register. All databases were searched from their respective inception until June 2001. Reference lists of articles were also searched for relevant material. Manufacturers of preparations containing artichoke extract and experts on the subject were contacted and asked to contribute published and unpublished material. SELECTION CRITERIA: Randomized controlled trials of ALE mono-preparations compared with placebo or reference medication for patients with hypercholesterolaemia were included. Trials assessing ALE as one of several active components in a combination preparation or as a part of a combination treatment were excluded. DATA COLLECTION AND ANALYSIS: Data were extracted systematically and methodological quality was evaluated using a standard scoring system. The screening of studies, selection, data extraction and the assessment of methodological quality were performed independently by two reviewers. Disagreements in the evaluation of individual trials were resolved through discussion. MAIN RESULTS: Two randomised trials including 167 participants met all inclusion criteria. In one trial ALE reduced total cholesterol levels from 7.74 mmol/l to 6.31 mmol/l after 42 +/- 3 days of treatment whereas the placebo reduced cholesterol from 7.69 mmol/l to 7.03 mmol/l (p=0.00001). Another trial did state that ALE significantly (p<0.05) reduced blood cholesterol compared with placebo in a sub-group of patients with baseline total cholesterol levels of more than 230 mg/dl. Trial reports and post-marketing surveillance studies indicate mild, transient and infrequent adverse events. REVIEWER'S CONCLUSIONS: Few data from rigorous clinical trials assessing ALE for treating hypercholesterolaemia exist. Beneficial effects are reported, the evidence however is not compelling. The limited data on safety suggest only mild, transient and infrequent adverse events with the short term use of ALE. More rigorous clinical trials assessing larger patient samples over longer intervention periods are needed to establish whether ALE is an effective and safe treatment option for patients with hypercholesterolaemia.

Humans↗
PubMed2002

Herbal medicine.

Generalized statements about herbal medicines are nonsensical, and each remedy has to be evaluated on its own merits. Some herbal treatments can be shown to have a favorable risk-benefit profile, but for most herbal medicines the data are insufficient to determine whether they do more good than harm. The research required to fill the gaps in present knowledge should have a high priority.

Animals↗
PubMed2002

Risks associated with herbal medicinal products.

Health risks associated with the use of herbal medicinal products (HMPs) are often an emotionally discussed issue. The topic is, however, important not least because of the present popularity of HMPs. This article aims to provide a factual overview of this complex subject. The evidence relating to the toxicity, interactions and quality of a number of HMPs is reviewed. Toxicity data indicate that some HMPs have the potential to cause serious adverse events and fatalities. HMPs affect pharmacokinetic and pharmacodynamic factors and thus cause herb-drug interactions. Reports of HMPs affected by contamination, adulteration or substitution of botanical material have repeatedly caused concern. Asian HMPs are most often implicated. It is concluded that HMPs are not free of risk. More research and more information are required in order to maximize consumers' safety.

Drug Contamination↗
PubMed2001

A profile of journals of complementary and alternative medicine.

An increasing amount of medical scientific information is published in specialised journals on various subjects, including complementary and alternative medicine (CAM). There are indications that positive findings may be published at the expense of methodological rigour. The aim of this investigation was to provide a profile of CAM journals currently available on Medline, and monitor trends in publication practice between the years 1995 and 2000. Systematic literature searches were performed to identify all CAM journals indexed in Medline. Journals published in 1995 and 2000 were identified by their title and content. Primary CAM research journals only were included in this analysis. All articles were read, data were extracted and categorised according to pre-defined criteria, e.g. type of methodology used, subject area, and direction of outcome. The number of original articles increased from a total of 61 in 1995 to 97 in 2000 across all four journals, the number of papers reporting clinical trials decreased by 4% between 1995 and 2000, and the number of surveys increased more than six times. Less positive and more negative articles were published in 2000 compared with 1995. The subject areas of papers varied greatly. The majority of articles published in 1995 suggested positive treatment effects, a phenomenon that was still present in 2000 albeit less strong. CAM journals, and most likely CAM itself, are associated with a lack of clinical trials and a bias in favour of positive conclusions.

Complementary Therapies↗
PubMed2001

Guar gum for body weight reduction: meta-analysis of randomized trials.

PURPOSE: To determine the efficacy of the dietary fiber guar gum as a therapeutic option for reducing body weight by conducting a meta-analysis of randomized controlled trials. METHODS: Literature searches were performed on the electronic databases Medline, Embase, Biosis, Amed, and the Cochrane Library. Manufacturers of commercial guar gum preparations and experts on the subject were contacted to provide any published or unpublished trials. For inclusion, trials had to state that they were randomized, double blinded, and placebo controlled, used guar gum monopreparations, and reported body weight as an endpoint. No language restrictions were imposed. Two reviewers independently extracted data in a standardized manner according to predefined criteria and evaluated methodological quality using the scoring system developed by Jadad. Discrepancies were settled through discussion. RESULTS: Thirty-four trials were identified and 20 could be included. Eleven trials provided data that were suitable for statistical pooling. The meta-analysis indicated a nonsignificant difference in patients receiving guar gum compared with patients receiving placebo (weighted mean difference -0.04 kg; 95% confidence interval (CI): -2.2 to 2.1). Analysis of six trials with similar methodologic features corroborates these findings (weighted mean difference -0.3 kg; 95% CI: -4.0 to 3.5). Adverse events most frequently reported were abdominal pain, flatulence, diarrhea, and cramps. Overall, 11 patients (3%) dropped out owing to adverse events. CONCLUSIONS: This meta-analysis suggests that guar gum is not efficacious for reducing body weight. Considering the adverse events associated with its use, the risks of taking guar gum outweigh its benefits for this indication. Therefore, guar gum cannot be recommended as a treatment for lowering body weight.

Double-Blind Method↗
PubMed2001

Kava extract for treating anxiety.

BACKGROUND: Synthetic anxiolytic drugs are effective for anxiety, but they are burdened with adverse events. Constraints on resources and time often render treatments such as psychological interventions impracticable. Thus, an effective and safe oral medication would be of considerable interest and a welcome addition to the therapeutic repertoire. OBJECTIVES: To systematically review the evidence regarding the efficacy and safety of kava extract for the symptomatic treatment of anxiety. SEARCH STRATEGY: Computerized literature searches were performed in the databases Medline, Embase, Biosis, AMED, CISCOM and the Cochrane Library (all from their respective inception to June 1998). The search terms used were kava, kawa, kavain, Piper methysticum and Rauschpfeffer (German common name for Piper methysticum). Manufacturers of kava preparations and experts on the subject were contacted and asked to contribute published and unpublished material. In addition, our own files were searched and the bibliographies of all of the studies identified were scanned for further trials. There were no restrictions regarding the language of publication. SELECTION CRITERIA: Randomized, double-blind trials of oral kava extract mono-preparations for the treatment of anxiety were included. Trials comparing kava with placebo were included. Trials assessing kava as one of several active constituents in a combination preparation or as a part of a combination treatment were excluded. DATA COLLECTION AND ANALYSIS: All publications were blinded prior to assessment by a person not involved in the study. Data on patients, interventions, methods, results and adverse events were extracted systematically. Methodological quality of all trials was evaluated using the scoring system developed by Jadad and colleagues. The screening of studies, selection, data extraction and the assessment of methodological quality were performed independently by the two reviewers. Disagreements in the evaluation of individual trials were resolved through discussion. MAIN RESULTS: Seven trials met the inclusion criteria. All of the reviewed trials suggest superiority of kava extract over placebo. The meta-analysis of three studies using the Hamilton Anxiety Score as a common outcome measure suggests a significant differential treatment effect in favour of kava extract (weighted mean difference: 9.69, 95% confidence interval: 3.54 - 15.83). Adverse events as reported in the reviewed trials were mild, transient and infrequent. REVIEWER'S CONCLUSIONS: These data imply that kava extract is superior to placebo and relatively safe as a symptomatic treatment for anxiety. These findings warrant further and more rigorous investigations into the efficacy and safety of kava extract.

Anxiety↗
PubMed2000

Garlic for treating hypercholesterolemia. A meta-analysis of randomized clinical trials.

PURPOSE: To investigate the effect of garlic on total cholesterol level in persons with elevated levels by conducting a meta-analysis of randomized, double-blind, placebo-controlled trials. DATA SOURCES: Systematic literature searches were conducted on the MEDLINE, EMBASE, BIOSIS, Cochrane Library, AMED, and CISCOM databases. Manufacturers of commercial garlic preparations and experts in the field were asked about published or unpublished trials. STUDY SELECTION: Selected trials were required to state that they were randomized, double-blind, and placebo-controlled; use garlic monopreparations; include persons with mean total cholesterol levels of at least 5.17 mmol/L (200 mg/dL); and report total cholesterol level as an end point. There were no language restrictions. DATA EXTRACTION: Two reviewers, blinded to key identifiers of each paper, independently extracted data in a standardized manner and assessed methodologic quality by using the Jadad scale. Discrepancies were settled through discussion. DATA SYNTHESIS: In the 13 trials included in the meta-analysis, garlic reduced total cholesterol level from baseline significantly more than placebo (P < 0.01); the weighted mean difference was -0.41 mmol/L (95% CI, -0.66 to -0.15 mmol/L) (-15.7 mg/dL [CI, -25.6 to -5. 7 mg/dL]). Six diet-controlled trials with the highest scores for methodologic quality revealed a nonsignificant difference between garlic and placebo groups; the weighted mean difference was -0.11 mmol/L (CI, -0.30 to 0.08 mmol/L) (-4.3 mg/dL [CI, -11.7 to 3.1 mg/dL]). CONCLUSIONS: The available data suggest that garlic is superior to placebo in reducing total cholesterol levels. However, the size of the effect is modest, and the robustness of the effect is debatable. The use of garlic for hypercholesterolemia is therefore of questionable value.

Chi-Square Distribution↗
PubMed2000

Feverfew for preventing migraine.

BACKGROUND: Feverfew (Tanacetum parthenium L.) is a popular herbal remedy for migraine. OBJECTIVES: To systematically review the evidence for or against the efficacy of feverfew versus placebo for the prevention of migraine. SEARCH STRATEGY: Electronic literature searches were performed using the databases CISCOM (Research Council for Complementary Medicine, London, UK), MEDLINE, EMBASE, Biosis and the Cochrane Library (each from its inception to April 1998). Manufacturers were contacted and the bibliographies of identified articles checked for further trials. SELECTION CRITERIA: Randomised, placebo-controlled, double-blind trials assessing the efficacy of feverfew for preventing migraine were included. No restrictions regarding the language of publication were imposed. DATA COLLECTION AND ANALYSIS: Data on patients, interventions, methods, outcomes and results were extracted in a pre-defined, standardised manner. Methodological quality was evaluated using the scoring system developed by Jadad and colleagues. Both data extraction and the assessment of methodological quality were performed independently by two reviewers. MAIN RESULTS: Four trials met the inclusion criteria. The majority of these trials suggested beneficial effects of feverfew compared with placebo. However, the trial with the highest methodological quality, which was also among the largest, found no significant difference between feverfew and placebo. REVIEWER'S CONCLUSIONS: The efficacy of feverfew for the prevention of migraine has not been established beyond reasonable doubt.

Complementary Therapies↗
PubMed2000

Ginkgo biloba extract for the treatment of intermittent claudication: a meta-analysis of randomized trials.

PURPOSE: The optimal treatment of intermittent claudication has not yet been identified. Ginkgo biloba extract has been reported to have beneficial effects. We performed a meta-analysis of the efficacy of Ginkgo biloba extract for intermittent claudication based on the results of randomized, placebo-controlled, double-blind trials. METHODS: Literature searches of MEDLINE, EMBASE, BIOSIS, AMED, CISCOM, and the Cochrane Library were performed to identify studies on the topic. Manufacturers of commercial Ginkgo biloba products and authors of original publications and reviews were contacted to provide additional information. No language restrictions were imposed. RESULTS: Eight randomized, placebo-controlled, double-blind trials were included. Meta-analysis found a significant difference in the increase in pain-free walking distance in favor of Ginkgo biloba (weighted mean difference: 34 meters, 95% confidence interval [CI]: 26 to 43 meters). In studies using similar methodological features (ergometer speed: 3 km/h, inclination: 12%) this difference was 33 meters in favor of Ginkgo biloba (95% CI: 22 to 43 meters). Adverse effects were rare, mild, and transient. CONCLUSIONS: These results suggest that Ginkgo biloba extract is superior to placebo in the symptomatic treatment of intermittent claudication. However, the size of the overall treatment effect is modest and of uncertain clinical relevance.

Double-Blind Method↗
PubMed2000

Location bias in controlled clinical trials of complementary/alternative therapies.

UNLABELLED: To systematically investigate location bias of controlled clinical trials in complementary/alternative medicine (CAM). METHODS: Literature searches were performed to identify systematic reviews and meta-analyses, which were used to retrieve controlled clinical trials. Trials were categorised by whether they appeared in CAM-journals or mainstream medical (MM)-journals, and by their direction of outcome, methodological quality, and sample size. RESULTS: 351 trials were analysed. A predominance of positive trials was seen in non-impact factor CAM- and MM-journals, (58) / (78) (74%) and (76) / (102) (75%) respectively, and also in low impact factor CAM- and MM-journals. In high impact factor MM-journals there were equal numbers of positive and negative trials, a distribution significantly (P < 0.05) different from all other journal categories. Quality scores were significantly lower for positive than negative trials in non-impact factor CAM-journals (P < 0.02). A similar trend was seen in low-impact factor CAM journals, but not to a level of significance (P = 0.06). There were no significant differences between quality scores of positive and negative trials published in MM-journals, except for high impact factor journals, in which positive trials had significantly lower scores than negative trials (P = 0.048). There was no difference between positive and negative trials in any category in terms of sample size. CONCLUSION: More positive than negative trials of complementary therapies are published, except in high-impact factor MM-journals. In non-impact factor CAM-journals positive studies were of poorer methodological quality than the corresponding negative studies. This was not the case in MM-journals which published on a wider range of therapies, except in those with high impact factors. Thus location of trials in terms of journal type and impact factor should be taken into account when the literature on complementary therapies is being examined.

Acupuncture Therapy↗
PubMed2000

The efficacy and safety of feverfew (Tanacetum parthenium L.): an update of a systematic review.

OBJECTIVE: Feverfew (Tanacetum parthenium L.) is a popular herbal remedy often advocated for the prevention of migraine. The aims of this systematic review are to update the evidence from rigorous clinical trials for or against the efficacy of feverfew for migraine prevention and to provide a safety profile of this herbal remedy. DESIGN: Literature searches were performed using the following databases: Medline, Embase, Biosis, CISCOM and the Cochrane Library (all from their inception to December 1999). Only randomized, placebo-controlled, double-blind trials of feverfew mono-preparations for the prevention of migraine in human subjects were included. All articles were read by two independent reviewers. Data were extracted in a pre-defined, standardized fashion. The methodological quality of the trials was evaluated by the Jadad score. For the assessment of safety issues, major reference texts were also consulted. RESULTS: Six trials met the inclusion/exclusion criteria. The majority favour feverfew over placebo. Yet important caveats exist. The data also suggest that feverfew is associated with only mild and transient adverse effects and few other safety concerns. CONCLUSIONS: Feverfew is likely to be effective in the prevention of migraine. There are no major safety problems.

Humans↗
PubMed2000

Efficacy of ginger for nausea and vomiting: a systematic review of randomized clinical trials.

Ginger (Zingiber officinale) is often advocated as beneficial for nausea and vomiting. Whether the herb is truly efficacious for this condition is, however, still a matter of debate. We have performed a systematic review of the evidence from randomized controlled trials for or against the efficacy of ginger for nausea and vomiting. Six studies met all inclusion criteria and were reviewed. Three on postoperative nausea and vomiting were identified and two of these suggested that ginger was superior to placebo and equally effective as metoclopramide. The pooled absolute risk reduction for the incidence of postoperative nausea, however, indicated a non-significant difference between the ginger and placebo groups for ginger 1 g taken before operation (absolute risk reduction 0.052 (95% confidence interval -0.082 to 0.186)). One study was found for each of the following conditions: seasickness, morning sickness and chemotherapy-induced nausea. These studies collectively favoured ginger over placebo.

Double-Blind Method↗