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PubMed1989

[Considerations of the placebo problem in acupuncture. Reflections on usefulness, ethical justification, standardization and differentiated use of placebos in acupuncture].

28 different acupuncture placebos were found in 28 controlled studies, making a comparison of the results impossible. The following differentiation of acupuncture placebos is proposed: 1.a) Real placebos without intrinsic effect, 1.b) Pseudoplacebos with intrinsic effect, 2.a) Placebos without damage of physical integrity (not incisive), 2.b) Placebos with damage of physical integrity (incisive), for example the usual method of placebo-acupuncture-needling outside the known acupuncture points with or without additional stimulation. Painful pseudoplacebos with damage of the physical integrity should only be used in short-term trials on experimentally induced pain in healthy volunteers. For therapeutic studies with really sick persons, only real placebos, painless and without damage of the physical integrity, should be used, e.g. mock-TENS or laser. In order to prevent the patient from knowing the group determination, a third group with another correct treatment is essential, e.g. correct acupuncture, mock-TENS and real TENS or laser. A genuine acupuncture placebo is as unthinkable as placebo-surgery. Since single- or double-blind trials cannot be correctly carried out in acupuncture therapy it appears desirable to replace them by follow-up studies.

Acupuncture Therapy↗
PubMed2003

Placebo effect and placebos: what are we talking about? Some conceptual and historical considerations.

Placebos and the placebo effect have always been present in medical history. However, they have not received the same consideration over the years. Somewhere between art and science, the placebo historical references come from Ancient Egypt and cross over the major civilisations, beliefs and scientific advances. The use of placebo as a methodological tool has assumed a leading role in the last 50 years and has become an important role in controlled clinical trials, the main element of the "evidence-based-medicine" paradigm. Knowledge of the conceptual and historical considerations of placebo may help to understand its role in medical practice. Even without a consensual definition, and assuming that the placebo effect does not seem to be fully dependent on a placebo administration, one issue seems unquestionable: the placebo effect is present in clinical practice and in clinical trials, no matter which name we choose to call it.

Clinical Trials as Topic↗
PubMed2002

[What is the effect of placebo interventions? A systematic review of randomized clinical trials with placebo treated and untreated patients].

INTRODUCTION: Placebo treatments have been reported to help patients with many diseases, but the quality of the evidence supporting this belief has not been rigorously evaluated. MATERIAL AND METHODS: We conducted a systematic review of clinical trials in which patients were randomised either to placebo treatment or to no treatment. A placebo intervention could be pharmacological (for instance, a tablet), physical (for instance manipulation), or psychological (for instance conversation). RESULTS: We identified 130 trials that met our inclusion criteria. After excluding 16, which gave no relevant outcome data, 32 with binary outcomes and 82 with continuous outcomes were left. As compared to no treatment, placebo had no significant effect on binary outcomes, the pooled relative risk was 0.95 (95% confidence interval 0.88 to 1.02), irrespective of whether these outcomes were subjective or objective. Placebo seemed to have a beneficial effect in the trials with continuous outcomes, the overall pooled standardised mean difference of the placebo and no-treatment groups was -0.28 (-0.38 to -0.19), but the effect decreased with increasing sample size, which indicates bias. The pooled standardised mean difference was significant for the trials with subjective outcomes, -0.36 (-0.47 to -0.25), but not for those with objective outcomes, -0.12 (-0.27 to 0.03). In trials involving the treatment of pain, placebo was reported to have a moderate beneficial effect, with a pooled standardised mean difference of -0.27 (-0.40 to -0.15), but bias, for instance reporting bias, was possible. CONCLUSION: We found no reliable evidence that placebo treatments in general had effects of clinical importance.

Evidence-Based Medicine↗
PubMed2002

Buprenorphine maintenance versus placebo or methadone maintenance for opioid dependence.

BACKGROUND: Buprenorphine has recently been reported to be an alternative to methadone and LAAM for maintenance treatment of opioid dependent individuals, differing results are reported concerning its relative effectiveness indicating the need for an integrative review. OBJECTIVES: To evaluate the effects of buprenorphine maintenance against placebo and methadone maintenance in retaining patients in treatment and in suppressing illicit drug use. SEARCH STRATEGY: We searched the following databases up to 2001, inclusive: Cochrane Drugs and Alcohol Review Group Register, the Cochrane Controlled Trials Register, MEDLINE, EMBASE, Current Contents, Psychlit, CORK [www. state.vt.su/adap/cork], Alcohol and Drug Council of Australia (ADCA) [www.adca.org.au], Australian Drug Foundation (ADF -VIC) [www.adf.org.au], Centre for Education and Information on Drugs and Alcohol (CEIDA) [www.ceida.net.au], Australian Bibliographic Network (ABN), and Library of Congress databases, available NIDA monographs and the College on Problems of Drug Dependence Inc. proceedings, the reference lists of all identified studies and published reviews and authors of identified RCT's were asked about any other published or unpublished relevant RCT. SELECTION CRITERIA: Randomised clinical trials of buprenorphine maintenance compared with either placebo or methadone maintenance for opioid dependence. DATA COLLECTION AND ANALYSIS: Reviewers evaluated the papers separately and independently, rating methodological quality of concealment of allocation; data were extracted independently for meta-analysis and double-entered. MAIN RESULTS: Thirteen studies met the inclusion criteria, all were randomised clinical trials, all but one were double-blind. The method of concealment of allocation was not clearly described in 11 of the studies, otherwise methodological quality was good. Buprenorphine given in flexible doses appeared statistically significantly less effective than methadone in retaining patient in treatment (RR= 0.82; 95% CI: 0.69-0.96). Low dose buprenorphine is not superior to low dose methadone. High dose buprenorphine does not retain more patients than low dose methadone, but may suppress heroin use better. There was no advantage for high dose buprenorphine over high dose methadone in retention (RR=0.79; 95% CI:0.62-1.01), and high dose buprenorphine was inferior in suppression of heroin use. Buprenorphine was statistically significantly superior to placebo medication in retention of patients in treatment at low doses (RR=1.24; 95% CI: 1.06-1.45), high doses (RR=1.21; 95% CI: 1.02-1.44), and very high doses (RR=1.52; 95% CI: 1.23-1.88). However, only high and very high dose buprenorphine suppressed heroin use significantly above placebo. REVIEWER'S CONCLUSIONS: Buprenorphine is an effective intervention for use in the maintenance treatment of heroin dependence, but it is not more effective than methadone at adequate dosages.

Buprenorphine↗
PubMed2001

Placebos, placebo effect, and the response to the healing situation: the evolution of a concept.

In spite of its impressive progress, medicine has been strongly criticized for relying on its modern biomedical tradition to the neglect of the psychosocial aspects of health. This neglect may account for patients' dissatisfaction and eventual use of alternative health approaches. The concept of placebo has sustained dramatic "protean" metamorphoses through the ages. For centuries, placebos have been regarded as powerful deceptive therapies. From the middle of the twentieth century, however, conventional medicine has used placebos as methodologic tools to distinguish the specific from the nonspecific ingredients in treatments. In modern medical research, the double-blind, placebo-controlled, randomized clinical trial has been established as the gold standard for the assessment of any new treatment. Recently a new trend regarding placebos seems to have emerged. The placebo and other nonspecific effects elicited by the "healing situation" have been independently subjected to scientific study. Progress in this area may promote useful clinical applications, enabling physicians to broaden their perspectives on the healing process. We present the historical changes of the concept of placebo and the ethical issues raised by their use.

Attitude to Health↗
PubMed2000

Chlorpromazine versus placebo for schizophrenia.

BACKGROUND: Chlorpromazine, formulated in the 1950s, remains a benchmark treatment for those with schizophrenia. OBJECTIVES: To evaluate the effects of chlorpromazine for schizophrenia in comparison to placebo. SEARCH STRATEGY: Electronic searches of Biological Abstracts (1982-1995), The Cochrane Library (1999, Issue 2), The Cochrane Schizophrenia Group's Register (October 1999), EMBASE (1980-1995), MEDLINE (1966-1995), PsycLIT (1974-1995) were undertaken. References of all identified studies were searched for further trial citations. Pharmaceutical companies and authors of trials were contacted. SELECTION CRITERIA: Randomised controlled trials relating to people with schizophrenia, and non-affective serious/chronic mental illness irrespective of mode of diagnosis evaluating chlorpromazine (any dose) versus placebo. Primary outcomes of interest were death, violent behaviours, overall improvement, relapse and satisfaction with care. DATA COLLECTION AND ANALYSIS: Citations and, where possible, abstracts were independently inspected by reviewers, papers ordered, re-inspected and quality assessed. Data were extracted by BT with CA and GA independently checking a 10% sample for reliability. Dichotomous data were analysed using random effects relative risk (RR) and the 95% confidence interval around this was estimated. Where possible the number needed to treat (NNT) or number needed to harm statistics (NNH) were calculated. Continuous data were excluded if more than 50% of people were lost to follow up, but, where possible, weighted mean difference was calculated. Sensitivity analyses have not been undertaken for this version of the review. MAIN RESULTS: Over 1000 electronic records were inspected. The review currently mentions 202 papers in its Excluded Studies section and 45 studies in its Included Studies table. Six papers await assessment. Chlorpromazine reduces relapse over six months to two years (RR 0.65 CI 0.5-0.9, NNT 3 CI 2.5-4) and there is convincing evidence from trials that it promotes a global improvement in a person's symptoms and functioning (RR 0.76 CI 0.7-0.9, NNT 7 CI 5-10) although the placebo response is also considerable (nearly 40%). Fewer people allocated to chlorpromazine leave trials early (RR 0.76 CI 0.6-1.1). There are many adverse effects. Chlorpromazine is clearly sedating (RR 2.4 CI 1.7-3.3, NNH 6 CI 4-8), it increases a person's chances of experiencing acute movement disorders (RR 3.1 CI 1.3-7.6, NNH 24 CI 14-77), parkinsonism (RR 2.6 CI 1.2-5.4, NNH 10 CI 8-16) and fits (RR 2.4 CI 0.4-16). Amongst other things it clearly causes a lowering of blood pressure with accompanying dizziness (RR 1.9 CI 1. 3-2.6, NNH 12 CI 8-22) and considerable increases in weight (RR 4.4 CI 2.1-9, NNH 3 CI 2-5). REVIEWER'S CONCLUSIONS: This review will confirm much that clinicians and recipients of care already know but provides quantification to support clinical impression. Despite the humbling 40% improvement rate in those who were allocated to placebo, chlorpromazine's global position as the 'benchmark' treatment of those with psychoses is not threatened by this review. Chlorpromazine, in common use for nearly half a century, is a well established but imperfect treatment. Judicious use of this best available evidence should lead to better informed decisions both by carers and those with psychotic illnesses.

Antipsychotic Agents↗
PubMed1997

A comparison of the effect of ramipril, felodipine and placebo on glomerular filtration rate, albuminuria, blood pressure and vasoactive hormones in chronic glomerulonephritis. A randomized, prospective, double-blind, placebo-controlled study over two years.

The effects of an ACE-inhibitor (ramipril), a calcium antagonist (felodipine) and placebo on glomerular filtration rate (GFR), urinary albumin/creatinine ratio, blood pressure (BP) and vasoactive hormones were investigated in a randomized, prospective, double-blind, placebo-controlled study of patients with chronic glomerulonephritis and hypertension, with measurements at entrance and after 12 and 24 months. In total, 33 patients were included: 21 completed the study with 7 patients in each group. GFR was measured as 51Cr-EDTA clearance and the vasoactive hormones with radioimmunoassays. The reduction in GFR was significantly more pronounced in the felodipine group (-7 ml/min) than in the ramipril group (0 ml/min) but the same as in the placebo group (-6 ml/min). The urinary albumin/creatinine ratio was significantly more reduced in the ramipril group (-74 mg/mmol) than in the placebo group (-11 mg/mmol), which did not deviate from the felodipine group (-10 mg/mmol). BP was significantly reduced by ramipril and felodipine, but not by placebo. Angiotensin II and aldosterone in plasma increased or tended to increase in the felodipine and placebo groups, but were unchanged in the ramipril group. Endothelin increased only in the placebo group, and vasopressin, atrial natriuretic peptide, and brain natriuretic peptide were not significantly changed in any of the groups. It is concluded that ramipril seems to be superior to felodipine in chronic glomerulonephritis owing to better preservation of GFR.

Adolescent↗
PubMed2001

Patients with severe depression may benefit from buspirone augmentation of selective serotonin reuptake inhibitors: results from a placebo-controlled, randomized, double-blind, placebo wash-in study.

BACKGROUND: Although case reports and open studies have reported augmentation with buspirone to be beneficial in the treatment of depression refractory to treatment with a selective serotonin reuptake inhibitor (SSRI), a recently published randomized, placebo-controlled, double-blind study failed to show superiority of buspirone over placebo in this respect. METHOD: One hundred two outpatients who fulfilled DSM-IV criteria for a major depressive episode and who had failed to respond to a minimum of 6 weeks of treatment with either fluoxetine or citalopram were included in this double-blind, randomized, placebo-controlled study. After a single-blind placebo wash-in period of 2 weeks while continuing their SSRI, the patients were randomly assigned to adjunctive treatment with either buspirone, 10 to 30 mg b.i.d., or placebo for 6 weeks. Patients were assessed using the Montgomery-Asberg Depression Rating Scale (MADRS), the Clinical Global Impressions scale (CGI), and visual analogue scales. RESULTS: After the first week of double-blind treatment, there was a significantly greater reduction in MADRS score (p = .034) in the buspirone group as compared with placebo. At endpoint, there was no significant difference between treatment groups as a whole, although patients with initially high MADRS scores (> 30) showed a significantly greater reduction in MADRS score (p = .026) in the buspirone group as compared with placebo. CONCLUSION: Patients with severe depressive symptoms may benefit from augmentation with buspirone. It cannot be excluded that augmentation with buspirone may speed up the antidepressive response of patients refractory to treatment with fluoxetine or citalopram.

Adult↗
PubMed2003

A double-blind, randomized, placebo-controlled trial of augmentation with lamotrigine or placebo in patients concomitantly treated with fluoxetine for resistant major depressive episodes.

BACKGROUND: Evidence of the antidepressant efficacy of lamotrigine is increasing, although there are no placebo-controlled trials of lamotrigine augmentation in depression. The aim of this study was to assess if augmentation with lamotrigine was superior to placebo in patients who were receiving fluoxetine for resistant major depressive episodes. METHOD: Twenty-three patients who had experienced at least 1 major depressive episode that was resistant to at least 1 prior trial of antidepressant therapy were selected. These patients were treated with fluoxetine, 20 mg/day, and concomitantly randomly assigned to receive either lamotrigine (N = 13) or placebo (N = 10) for 6 weeks. The dose of lamotrigine was titrated upward from 25 mg/day to 100 mg/day. Patients suffering from bipolar II disorder (N = 8) or from major depressive disorder (N = 15) (DSM-IV criteria) were enrolled, resulting in heterogeneity of the sample. The primary outcome measure was Hamilton Rating Scale for Depression score. Data were collected from 2000-2001. RESULTS: Lamotrigine was statistically superior to placebo on the Clinical Global Impressions scale at endpoint, both in absolute terms (mean +/- SD Clinical Global Impressions-Severity of Illness scores: lamotrigine, 2.15 +/- 1.28; placebo, 3.40 +/- 1.17; p =.0308) and using a responder analysis, with response defined as a Clinical Global Impressions-Improvement score of 2 or less (lamotrigine, 84.62% [N = 11]; placebo, 30.00% [N = 3]; p =.013). The effect of lamotrigine on Clinical Global Impressions scale scores was seen in both major depressive disorder and bipolar II disorder. Lamotrigine, however, failed to separate statistically from placebo on the Hamilton Rating Scale for Depression and Montgomery-Asberg Depression Rating Scale. This failure to differentiate on a primary outcome measure is essentially a negative study result. This result is most likely an artifact of the small sample size used and the resultant limited power of the study. CONCLUSION: The results of this trial add to the literature suggesting potential efficacy of the antidepressant profile of lamotrigine. In addition, this study points to a possible role of lamotrigine as an augmentation agent in depression.

Adolescent↗
PubMed1986

Responders, nonresponders, and placebo responders among children with attention deficit disorder. Importance of a blinded placebo evaluation.

The responses to methylphenidate of 118 children with attention deficit disorder (ADD) were studied under double-blind conditions. Three distinct types of response to medication and placebo were found, as determined by teacher ratings. One group, called "responders," improved dramatically in attention and hyperactivity ratings on active medication but showed essentially no change from baseline when on placebo. The group called "nonresponders" showed minimal change in ratings on either placebo or medication. The third group, "placebo responders," showed almost as much improvement as the responders on medication, but their ratings were not very different from medication ratings during the placebo trial. The placebo responders, 18 percent of the group, would have been considered responders in a nonplacebo-controlled study. Double-blind placebo evaluation of ADD children can and should be done by practitioners to avoid medicating children who are responding to nonspecific effects of drugs.

Analysis of Variance↗
PubMed1996

Evaluation by 24-hour ambulatory blood pressure monitoring of efficacy of manidipine hydrochloride 10, 20 or 40 mg once daily as compared to placebo in treating mild to moderate essential hypertension: a double-blind, randomized, parallel group, placebo-controlled study.

In a double-blind, randomized, placebo-controlled, parallel-group study the ambulatory blood pressure monitoring (ABPM) and relative tolerability of different doses of manidipine hydrochloride (10, 20 and 40 mg) were compared to placebo in patients with mild to moderate essential hypertension. After an initial 2-week run-in period on placebo, 52 patients, 32 males and 20 females, aged 40 to 63 years, were randomized to receive manidipine 10 mg, 20 mg, 40 mg or placebo, all administered once daily for 4 weeks. Patients were checked after the initial placebo phase and every 2 weeks thereafter. At each visit, casual BP and HR were measured. At the end of the placebo period and after 4 weeks of active treatment, non-invasive 24-h ABPM was performed. 24-h, day-time and night-time ambulatory BP as well as the area under the curve (AUC) and casual BP were dose-dependently reduced by manidipine 10, 20 and 40 mg, without changes in the normal BP circadian profile. The trough:peak ratio for both SBP and DBP was higher than 50% for all three manidipine dosage regimens. The percentage of abnormal ambulatory SBP and DBP readings was significantly reduced in all manidipine-treated groups versus placebo. The risk/benefit ratio suggests that the intermediate manidipine dosage (20 mg) could be a suitable dose regimen for the majority of patients with mild to moderate hypertension.

Adult↗
PubMed2000

A comparison of drugs versus placebo for the treatment of dysthymia.

OBJECTIVES: Dysthymia is a depressive disorder of chronic nature but of less severity than major depression, which depressive symptoms are more or less continuous for at least two years. The aim of this review was to conduct a systematic review of all RCTs comparing drugs and placebo for dysthymia. SEARCH STRATEGY: Electronic searches of Cochrane Library, EMBASE, MEDLINE, PsycLIT, Biological Abstracts and LILACS; reference searching; personal communication; conference abstracts; unpublished trials from the pharmaceutical industry; book chapters on the treatment of depression. SELECTION CRITERIA: The inclusion criteria for all randomised controlled trials were that they should focus on the use of drugs versus placebo for dysthymic patients. Exclusion criteria were: non randomised, mixed major depression/ dysthymia (trials not providing separate data) and depression secondary to other disorders (e.g. substance abuse). DATA COLLECTION AND ANALYSIS: The reviewers extracted the data independently. In order to achieve an intention-to-treat analysis, when trials failed to report it was assumed that people who died or dropped out had no improvement. Authors of relevant trials were contacted for additional and missing data. Absence of treatment response as defined by authors was the main measure of outcome used. Relative Risks (RR) and 95% confidence intervals (CI) of dichotomous data were calculated with the Random Effects Model. Where possible, number needed to treat (NNT) and number needed to harm (NNH) were estimated, taking the reciprocal of the absolute risk reduction. MAIN RESULTS: Currently the review includes 15 trials. Similar results were obtained in terms of efficacy for different groups of drugs, such as tricyclic (TCA), selective serotonin reuptake inhibitors (SSRI), monoamine oxidase inhibitors (MAOI) and other drugs (sulpiride, amineptine, and ritanserin). The pooled RR for absence of treatment response was 0. 68 (95% CI 0.59-0.78) for TCA and the NNT was 4.3 (95% CI 3.2-6.5). SSRIs showed similar RR for this outcome: 0.64 (95% CI 0.55-0.74), the NNT being 4.7 (95% CI 3.5-6.9). Concerning MAOIs, the RR was 0. 59 (95% CI 0.48-0.71) and the NNT was 2.9 (95% CI 2.2-4.3). Other drugs (amisulpride, amineptine and ritanserin) showed similar results in terms of absence of treatment response. Using more stringent criteria for improvement - full remission - the results were unchanged. Patients treated on TCA were more likely to report adverse events, compared with placebo. REVIEWER'S CONCLUSIONS: Drugs are effective in the treatment of dysthymia with no differences between and within class of drugs. Tricyclic antidepressants are more likely to cause adverse events and dropouts. As dysthymia is a chronic condition, there remains little information on quality of life and medium or long-term outcome.

Antidepressive Agents↗
PubMed1993

Aspartame is no more likely than placebo to cause urticaria/angioedema: results of a multicenter, randomized, double-blind, placebo-controlled, crossover study.

BACKGROUND: Anecdotes and single case reports have suggested that the high-intensity sweetener, aspartame, may be associated with allergic/hypersensitivity-type reactions. METHODS: We conducted a multicenter, placebo-controlled clinical study to evaluate individuals who had experienced urticaria and/or angioedema allegedly associated with ingestion of an aspartame-containing product. Despite extensive recruiting efforts over 4 years, only 21 subjects could be enrolled. After admission to clinical research units, subjects were given aspartame and placebo in a randomized, double-blind, crossover fashion. Subjects received, on different days, increasing doses (50, 300, 600 mg) of aspartame and placebo at 8:00 AM, 10:00 AM, and noon. Subjects who weighed less than 40 kg received one half of these doses. Conversion products of aspartame, aspartyl-phenylalanine diketopiperazine and beta-aspartame, were also included in the aspartame arm of the study. Positive reactions were defined as urticaria (hives with wheals 4 mm or more in diameter with a collective diameter of at least 15 mm or one or more hives with a wheal of 4 mm or greater with a flare of 8 mm or greater) or as angioedema. RESULTS: According to these criteria, four reactions were observed; two followed aspartame ingestion and two followed placebo ingestion (p = 1.00). The incidence of other adverse experiences was no different after aspartame versus placebo ingestion (p = 0.289). CONCLUSION: These results indicate that aspartame and its conversion products are no more likely than placebo to cause urticaria and/or angioedema reactions in subjects with a history consistent with hypersensitivity to aspartame.

Administration, Oral↗