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PubMed1993

Double-blind, controlled, multicenter study of indobufen versus placebo in patients with intermittent claudication.

The objective of the study was to evaluate the efficacy and safety of indobufen compared with placebo in the treatment of moderately severe intermittent claudication. The study consisted of a four-week single-blind, placebo-controlled run-in phase, followed by a six-month double-blind randomized treatment period. A total of 302 patients were allocated to treatment with either placebo (154 patients) or indobufen (148) 200 mg twice daily. The results of the overall intention-to-treat analysis of the study population showed statistically significant superiority of indobufen over placebo after six months for both the initial (ICD) and absolute claudication distances (ACD). The ICD before treatment with indobufen or placebo averaged 137.9 +/- 68.2 and 136.6 +/- 63.2 m (mean +/- SD), respectively. After six months' treatment with active drug or placebo, this parameter reached 227.9 +/- 174.4 and 153.1 +/- 86.8 m (mean +/- SD), respectively (p < 0.01). Similar results were obtained on ACD. The reduction of lower limb symptoms also suggested a greater clinical benefit in the indobufen-treated patients. There was no significant change in either group in the ankle/arm pressure ratio at the end of treatment. Adverse events of any type were reported by 18 patients (12.2%) in the indobufen group and by 11 patients (7.2%) in the placebo group. The mechanism whereby the drug is effective in this clinical condition could be related to both its antiplatelet and hemorheologic effects.

Double-Blind Method↗
PubMed1996

Efficacy of venlafaxine and placebo during long-term treatment of depression: a pooled analysis of relapse rates.

The objective of this analysis was to determine the efficacy of venlafaxine in comparison with that of placebo during long-term treatment. A pooled analysis of relapse rates in outpatients with major depression continuing long-term treatment (up to 12 months) after responding to short-term treatment (6 weeks) was performed combining the data from four randomized, double-blind, placebo-controlled clinical trials. Relapses were defined as two consecutive Clinical Global Impression (CGI) severity scores greater than 3 (mildly ill), as a CGI severity score greater than 3 at withdrawal regardless of the reason for withdrawal, or as withdrawal due to lack of efficacy. Data from 304 patients (185 venlafaxine, 119 placebo) well balanced for baseline characteristics were included in the pooled analysis. Percentages of patients completing the long-term phase were 38% venlafaxine and 26% placebo (p = 0.034). Cumulative relapse rates by 6 months of long-term treatment were 11% venlafaxine and 23% placebo (p = 0.019). Cumulative relapse curves for the venlafaxine and placebo groups over the 1-year long-term treatment differed significantly (p = 0.022). The results from this analysis indicate that long-term treatment with venlafaxine in patients with major depressive disorder is effective in maintaining the initial response compared with placebo and suggest that venlafaxine will be effective in the prevention of relapse.

Adult↗
PubMed1996

[Placebo-controlled double-blind study of the effectiveness of Ginkgo biloba special extract EGb 761 in trained patients with intermittent claudication].

This monocenter, randomized, placebo-controlled double-blind study with parallel-group comparison was carried out in order to demonstrate the efficacy of Ginkgo biloba special extract EGb 761 on objective and subjective parameters of the walking performance in trained patients suffering from peripheral arterial occlusive disease in Fontaine stage IIb. In total 60 patients were recruited (42 men; aged 47-82 years) with angiographically proven peripheral arterial occlusive disease of the lower extremities and an intermittent claudication existing for at least 6 months. No improvement had been shown despite consistent walking training and a maximum pain-free walking distance on the treadmill of less than 150 m was recorded at the beginning of the study. The therapeutic groups were treated with either Ginkgo biloba special extract EGb 761 at a dose of 3 times 1 film-coated tablet of 40 mg per day by oral route or placebo over a duration of 24 weeks following a two-week placebo run-in phase. The main outcome measure was the difference of the walking distance between the start of treatment and after 8, 16 and 24 weeks of treatment as measured on the treadmill (walking speed 3 km/h and slope of 12%). As secondary parameters the corresponding differences for the maximum walking distance, the relative increase of the pain-free walking distance, the Doppler index and the subjective evaluation of the patients were analyzed. The absolute changes in the pain-free walking distance in treatment weeks 8, 16 and 24 as against the treatment beginning (median values with 95% confidence interval) led to the following values for the patients treated with Ginkgo biloba special extract EGb 761:19 m (14, 33), 34 m (18, 50) and 41 m (26, 64). The corresponding values in the placebo group were as follows: 7 m (-4, 12), 12 m (5, 22) and 8 m (-1, 21). The advantage of the EGb 761-treated group as compared to the placebo group could be verified statistically at the 3 time points with p < 0.0001, p = 0.0003 and p < 0.0001. The test for the presence of a clinically relevant difference of 20% between EGb 761 and placebo also produced a statistically significant result (p = 0.008). The Doppler index remained unchanged in both therapeutic groups: A corresponding statistically significant advantage for the EGb 761 group was observed on a descriptive level for the other parameters tested. The tolerance of the treatment was very good. The results of this placebo-controlled study show that treatment with Ginkgo biloba special extract EGb 761 produces a statistically highly significant and clinically relevant improvement of the walking performance in trained patients suffering from intermittent claudication with very good tolerance of the study preparation.

Aged↗
PubMed1997

Comparison of the efficacy and safety of ebrotidine in the treatment of duodenal ulcer. A multicentre, double-blind, placebo-controlled phase II study.

Ebrotidine (N-[(E)-[[2-[[[2-[(diaminomethylene)amino]-4 -thiazoly]methyl]thio]ethyl]amino]methylene]-4-bromo-benzenesulfon amide, CAS 100981-43-9, FI-3542) is a new H2-receptor antagonist characterized by its high receptor affinity and gastroprotective effect. This Phase II study has been undertaken to establish the efficacy and safety of ebrotidine, administered in four dosages as a single evening dose versus placebo in the treatment of duodenal ulcer. A total of 110 duodenal ulcer patients were studied in a randomized, double-blind, placebo-controlled, multicentre clinical trial. The patients were assigned to 5 groups: placebo, 200 mg, 400 mg, 600 mg and 800 mg of ebrotidine once daily. Controls were performed at baseline and every two weeks at four follow-up visits unless ulcer healed before. Endoscopic examination was the main parameter for the assessment of treatment efficacy and ulcer healing rate. Vital signs and blood/ urine analysis were used to establish safety. The three groups treated with higher dosages (400 to 800 mg of ebrotidine daily) showed an endoscopic ulcer healing rate of 90-95%, significantly higher than 55% achieved with placebo (p < 0.05), whilst the differences between these three dosages of ebrotidine were not statistically significant. Healing rate in the group treated with 200 mg of ebrotidine daily was not significantly different from that in the placebo group. The development of symptoms, number of episodes of ulcer-related pain, total ulcerated surface area or subjective ratings by the patients and investigators also differed significantly between ebrotidine (400, 600 and 800 mg daily) and placebo, and again, no marked differences were found between these three doses of ebrotidine. As far as tolerance is concerned, no clinically or statistically significant changes were observed in vital signs and analytical parameters. The incidence of side effects was less than that presented by the placebo group, possibly due to a greater consumption of antacids in this group. Results showed that a daily dose of 400 mg ebrotidine is effective and safe in the treatment of duodenal ulcers.

Abdominal Pain↗
PubMed1997

Oral desmopressin: a randomized double-blind placebo controlled study of effectiveness in children with primary nocturnal enuresis.

PURPOSE: Desmopressin nasal spray has proved to be efficacious treatment of primary nocturnal enuresis. Oral desmopressin tablets would be a more easily used, convenient vehicle for our patients and their parents. We evaluated the effectiveness of oral desmopressin in decreasing the number of wet nights in patients with primary nocturnal enuresis. MATERIALS AND METHODS: We performed a double-blind, placebo controlled, parallel group trial of oral desmopressin in 141 children 5 to 17 years old with documented primary nocturnal enuresis at 14 sites. Patients were screened for number of wet nights for 2 weeks before study entry. A minimum of 3 wet nights weekly for 2 consecutive weeks was required for study entry. Patients were randomized to receive 200, 400 or 600 mcg. desmopressin or placebo before bedtime. Fluids were restricted 2 hours before bedtime based on body weight. The primary efficacy variable was mean decrease in the number of wet nights recorded during the last 2-week treatment period. The percentage of responding patients and mean decrease from baseline in number of wet nights at 2, 4 and 6 weeks were also assessed. RESULTS: The decrease in wet nights was 9, 20, 30 and 36% for placebo, and 200, 400, and 600 mcg. desmopressin orally per day, respectively. The 600 mcg. dose of oral desmopressin daily was statistically significantly different (p < 0.05) from placebo in decreasing wet nights. A complete or near complete response (0 to 2 wet nights) was noted in 3, 18, 33 and 24% of the patients who received placebo, and 200, 400 and 600 mcg. oral desmopressin daily, respectively. The 400 and 600 mcg. treatment groups were statistically significantly different (p < 0.05) from placebo. A less than 50% decrease in wet nights was noted in 83, 79, 64 and 61% of the patients who received placebo, and 200, 400 and 600 mcg. oral desmopressin daily, respectively. Oral desmopressin exhibited a dose response in the treatment of primary nocturnal enuresis. The linear trend for the decrease in wet nights was statistically significant (p < 0.05). CONCLUSIONS: A dose of 600 mcg. oral desmopressin daily significantly decreased the mean number of wet nights when administered for 6 weeks. A higher dose may be necessary for an improved response.

Administration, Oral↗
PubMedDate not supplied

[Comparison of 6 different methods for lorazepam withdrawal. A controlled study, hydroxyzine versus placebo].

PATIENTS AND METHODS: 154 outpatients with generalized anxiety (DSM III-R criteria), followed by general practitioners, gave an informed written consent to participate in this multicenter, randomized, placebo controlled study previously approved by a legal ethic committee (CCPPRB). The patients had to be long term consumers (at least 3 months) of 2 mg daily of lorazepam and were withdrawn using transiently an antihistaminic anxiolytic (hydroxyzine or placebo TAD) according to 6 different procedures defining 6 parallel groups: hydroxyzine 50 mg, abrupt or progressive withdrawal; hydroxyzine 25 mg, abrupt or progressive withdrawal; placebo, abrupt or progressive withdrawal. Following this 4 week-period of withdrawal, the patients were without any treatment for a post-study follow up 2 month-period. Clinical evaluations for anxiety (HARS, Zung), sleep (Spiegel), BZD withdrawal syndrome (Tyrer), adverse reactions and clinical global impression (CGI) were performed at D0, D7, D14, D28, D35 and D88. Investigators opinion and patients attitude towards BZD were collected at D88. STATISTICAL ANALYSIS: Analysis of variance for quantitative variables and chi square test for qualitative or ordinal variables. RESULTS: Whatever abrupt or progressive, with or without hydroxyzine support, using half or full dosage, lorazepam withdrawal proved to be feasible even after a long term BZD treatment (mean = 64 months +/- 60). GPs opinion (72% satisfied: D35; 78% satisfied: D88) is satisfying but patients attitude (at D88: 54% patients desired to be regiven a tranquilizer, 31% patients occasionally had a BZD and 22% formally demanded a prescription of BZD) is more questionable. Despite a high initial level of anxiety under lorazepam (HARS = 21 +/- 10 at D0), after a one-month period of withdrawal (under placebo or hydroxyzine) followed by a 2 month-period without any treatment, 75% patients were totally free of any drug and their level of anxiety was significantly decreased (D88: HARS = 12 +/- 9). Progressive withdrawal appeared preferable if compared to abrupt since the number of drop outs between D28 and D88 was less important and the procedure judged more favourably by the patients. Levels of anxiety significantly decreased in both the groups (progressive and abrupt) but sleep parameters and number of withdrawal symptoms between D7 and D28 were improved only in abrupt withdrawal group (p < 0.0001). Considering hydroxyzine, 2 patients dropped out between D0 and D28 in the group hydroxyzine 25 mg, 6 patients in the group 50 mg and 5 patients in the group placebo. Levels of anxiety (HARS et Zung) were significantly improved in hydroxyzine 50 mg group (p < 0.007) and in hydroxyzine 25 mg group (p < 0.012) but not in placebo group. Withdrawal symptoms (Tyrer) between D0 and D28 were improved only in hydroxyzine 50 mg group and the number of side effects was significantly improved in both the hydroxyzine (25 et 50 mg) groups but not in placebo group. However, no significant difference was found between the 3 groups. Daytime sleepiness is more frequent in hydroxyzine 50 mg group. DISCUSSION: These results proved a significant improvement of anxiety, a decrease of side effects in both the groups treated with hydroxyzine and a reduction of withdrawal symptomatology in hydroxyzine 50 mg group. When a patient is engaged to be withdrawn from of a lorazepam long term treatment, it can therefore be proposed as a support a transient prescription of hydroxyzine 25 mg TAD to markedly anxious patients and of hydroxyzine 50 mg TAD to patients presenting a withdrawal symptomatology.

Adolescent↗
PubMed1997

Efficacy and safety of avocado/soybean unsaponifiables in the treatment of symptomatic osteoarthritis of the knee and hip. A prospective, multicenter, three-month, randomized, double-blind, placebo-controlled trial.

One of the objectives of symptomatic slow-acting drugs for osteoarthritis is to reduce the need for drugs with a less favorable safety profile, mainly analgesics and nonsteroidal antiinflammatory drugs (NSAIDs). We conducted a three-month, prospective, randomized, double-blind, placebo-controlled, parallel-group trial to evaluate the efficacy of avocado/soybean unsaponifiables in terms of NSAID use reduction. Patients with primary femorotibial or hip osteoarthritis (OA) (ACR criteria and Kellgren-Lawrence radiological stage IB, II, or III) of at least six months' duration with regular pain for more than three months requiring therapy with NSAID (visual analog scale score > or = 25 mm and Lequesne's index on therapy > or = 4) were given one capsule per day of avocado/soybean unsaponifiables or a placebo for three months. During the first 45 days, patients in both groups were also given one of seven predefined NSAIDs. The primary efficacy criteria was the rate of patients taking back a NSAID and the delay before re-intake. Secondary efficacy criteria were the total dose of NSAID, overall ratings by the patient and by the physician, the visual analog scale pain score and the functional index. Of the 164 included patients, 163 were evaluable, 80 in the active drug group and 83 in the placebo group. Mean age was 62.9 +/- 8.8 years. The diagnosis was femorotibial OA in 101 patients and hip OA in 62. Data were collected on day 45 in 153 patients (77 on the active drug and 76 on the placebo). The number of patients who took back NSAID therapy was significantly smaller in the group treated by avocado/soybean unsaponifiables (33; 43.4%) than in the placebo group (53; 69.7%) (P < 0.001). Also, beyond day 54, the time spent off NSAID therapy was shorter in the placebo group. The functional index showed a significantly greater improvement in the active drug group (-2.3 +/- 2.6) than in the placebo group (-1.0 +/- 2.6) (P < 0.01). Pain scores over time were similar in the two groups. Overall patient ratings were significantly better in the active drug group (P < 0.01). Safety was oggd in both groups. After six weeks, avocado/soybean unsaponifiables reduced the need for NSAID in patients with lower limb OA.

Aged↗
PubMed1997

Characteristics of fluoxetine versus placebo responders in a randomized trial of geriatric depression.

Results from placebo-controlled trials of antidepressants can be used to identify patients most likely to benefit from medication. Using data from a randomized clinical trial of fluoxetine versus placebo for 671 elderly outpatients with major depression, we evaluated characteristics of those who improved with and without active medication. We found that the choice of outcome measure made a difference when evaluating the effectiveness of fluoxetine relative to placebo and determining the accuracy of predictive variables in both treatment groups. Generally, less severe depression predicted favorable response (greater than 50% improvement on the 21-item Hamilton Rating Scale for Depression [HAM-D-21], less than 3 on the Clinical Global Impressions [CGI] and Patient Global Impressions [PGI] improvement scales) and remission (less than 9 on 6-week HAM-D-21) with both fluoxetine and placebo. Less anxiety/somatization was associated with favorable fluoxetine response, and lower levels of cognitive and sleep disturbance were associated with remission in the placebo group. By contrast, higher levels of psychomotor retardation in the placebo group were associated with clinician and patient ratings of much or very much improved. The similarities among responders in both groups may indicate that some in the fluoxetine group would have improved with placebo.

Aged↗
PubMed1998

Hormone therapy in women in the menopause transition. Randomised, double-blind, placebo-controlled trial of effects on body weight, blood pressure, lipoprotein levels, antithrombin III activity, and the endometrium.

OBJECTIVE: To determine whether hormone treatment of women during the menopause transition induces changes in body weight, blood pressure, lipoprotein levels, antithrombin III activity, and the endometrium. DESIGN: Prospective, randomised, placebo-controlled, double-blind, 12-month study, with crossover at 6 months. SETTING: Outpatient clinic of a city hospital. PARTICIPANTS: 105 apparently healthy women in the menopause transition (40-52 years), with menstrual function, who were experiencing minor menopausal symptoms, were selected from the general population by advertising. INTERVENTIONS: Active arm--oral conjugated oestrogens (0.625 mg daily) and cyclic medroxyprogesterone acetate (10 mg daily) on Day 14-27 of each menstrual cycle; placebo arm--placebos of both medications. MAIN OUTCOME MEASURES: Excess change from baseline associated with active compared with placebo treatment for all variables; effect of order of treatment. RESULTS: Baseline biochemical values were similar for both treatment-order groups, but baseline blood pressures and body weights were higher in the group receiving placebo first. With treatment, there were no differences in overall values for body weight and blood pressure (P > 0.4), and order of treatment had no significant influence (P > 0.3). There were no differences in total and low density lipoprotein cholesterol levels, overall or with order of treatment. Active treatment increased high density lipoprotein (HDL) cholesterol levels (overall and when placebo was given first; P = 0.001), and triglyceride levels (when active treatment was given first; P = 0.03). There was no overall treatment effect, but a significant order-of-treatment effect, on antithrombin III activity (mean levels were decreased by active treatment to a greater extent when it was given first; P = 0.02). The endometrium showed only physiological changes regardless of treatment. CONCLUSIONS: The lack of significant excess change in anthropometry, lipoprotein levels, antithrombin III activity, and endometrial histology in women given hormone treatment compared with placebo is reassuring. The increase in HDL cholesterol level is an extra benefit. Our study provides conclusive evidence that hormone treatment does not produce weight gain in women during the menopause transition.

Adult↗
PubMed1998

Prevention of gastroduodenal damage with omeprazole in patients receiving continuous NSAIDs treatment. A double blind placebo controlled study.

AIM: The aim of this study was to compare omeprazole (20 mg once daily) with placebo in the long-term prevention of gastroduodenal lesions induced by indomethacin, diclofenac and ketoprofen. PATIENTS AND METHODS: 114 patients with arthritic disorders and requiring indomethacin, diclofenac or ketoprofen were randomized in a double blind manner to receive omeprazole-20 mg once daily- or identical placebo for three weeks. The gastroduodenal mucosa damage was scored according to a 0-4 point endoscopic scale. RESULTS: Of the 114 patients, 103 (50 in the omeprazole group, 53 in the placebo group) were submitted to endoscopy, while 11 patients dropped out for non-medical reasons. At the final endoscopy, 26/57 (46%) of omeprazole group, and 20/57 (35%) of the placebo group had normal gastroduodenal mucosa (score = 0) (p ns; 95% IC -0.073 + 0.284). A gastric ulcer was observed in 7/57 (12%) patients, all in the placebo group (p < 0.01 vs omeprazole); 2 patients (1 in the omeprazole group and 1 in the placebo group) developed a duodenal ulcer. Dyspeptic symptoms developed in 10% of the patients treated with omeprazole and 29% of those receiving placebo (p ns). CONCLUSIONS: Omeprazole, 20 mg once daily, provides effective prophylactic therapy in patients at risk of developing NSAID-associated gastric and duodenal ulcer.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1998

A second phase III multicenter placebo controlled study of 2 dosages of modified release tamsulosin in patients with symptoms of benign prostatic hyperplasia. United States 93-01 Study Group.

PURPOSE: In a double-blind, phase III clinical trial we evaluate the safety and efficacy of 0.4 and 0.8 mg. tamsulosin daily for the treatment of patients with symptoms of moderate to severe benign prostatic hyperplasia. MATERIALS AND METHODS: Patients meeting the basic requirements of the study underwent a 4-week single-blind placebo evaluation period. A total of 735 patients were randomized to double-blind therapy with tamsulosin or placebo. Treatment duration was 13 weeks. Efficacy and safety were evaluated at 5 visits during the double-blind treatment period. RESULTS: When efficacy data between baseline and end point were compared there was a significant reduction in total American Urological Association symptom score (25%) in each tamsulosin group compared with placebo (p = 0.01) and the percentage of patients with a 30% or more reduction in peak urinary flow rate was significantly greater in the tamsulosin versus placebo group (p <0.05). Improvements in American Urological Association symptom scores and maximum flow rate occurred at 1 week of treatment. None of the patients experienced a first dose effect. There were no significant changes in blood pressure on standing at any visit during the study except for a decrease in systolic blood pressure of 20 mm. Hg or more between the 0.8 mg. dose and placebo groups at visit 4 (p = 0.036). Positive orthostatic tests were significantly more frequent in the 0.8 mg. group compared with placebo at visit 4 (p = 0.012). The treatment groups did not differ significantly in incidence of electrocardiogram abnormalities at each post-baseline visit and at end point. CONCLUSIONS: Tamsulosin was safe and effective, and clinically and statistically superior to placebo in relieving symptoms of benign prostatic hyperplasia in men with moderate to severe symptoms at baseline. There was no evidence of a first dose effect and no clinically significant orthostatic hypertension. In addition, response to treatment was rapid.

Adrenergic alpha-Antagonists↗
PubMed2006

Expectations and associations that heal: Immunomodulatory placebo effects and its neurobiology.

The use of placebo may have accompanied healing and medical practices since their origins (Plato; Charmides, 155-156). Recent experimental data indicate that we would be well advised to further consider placebo effects in future therapeutic strategies, with a better knowledge of their potency, psychological basis and underlying neurobiological mechanisms. Current research in the areas of pain, depression and Parkinson's disease has uncovered some of the potential neurobiological mechanisms of placebo effects. These data indicate that conscious expectation and unconscious behavioral conditioning processes appear to be the major neurobiological mechanisms capable of releasing endogenous neurotransmitters and/or neurohormones that mimic the expected or conditioned pharmacological effects. To date, research on placebo responses affecting immune-related diseases is scarce, but there are consistent indications that skin and mucosal inflammatory diseases, in particular, are strongly modulated by placebo treatments. However, the brain's capability to modulate peripheral immune reactivity has been impressively demonstrated by paradigms of behavioral conditioning in animal experiments and human studies. Thus, placebo effects can benefit end organ functioning and the overall health of the individual through positive expectations and behavioral conditioning processes.

Brain↗
PubMed2006

The nature and power of the placebo effect.

Progress in understanding the placebo effect and its clinical significance depends on conceptual clarification of this elusive phenomenon and critical appraisal of research bearing on the influence of placebo interventions on clinical outcomes. Here we locate the placebo effect within a typology of modes of healing, distinguish between the observed placebo response in randomized controlled trials and the placebo effect, and examine critically a recent meta-analysis of clinical trials that challenges the reality of the placebo effect.

Analgesia↗
PubMed2005

Endogenous opiates and the placebo effect: a meta-analytic review.

OBJECTIVE: A meta-analysis was performed to investigate the ability of placebo administration to reduce self-report of pain and to examine whether placebo-induced pain reduction might have physiological and psychological underpinnings. METHOD: Forty-five effect sizes and 1183 participants from 12 studies were meta-analyzed for the effects of placebo and the opioid antagonist, naloxone, on self-report of pain. RESULTS: Analyses showed that placebo administration was associated with a decrease in self-report of pain, and a hidden or blind injection of naloxone reversed placebo-induced analgesia. Furthermore, there were significant between-group differences for type of pain (experimental vs. postoperative/clinical) for placebo studies. CONCLUSIONS: The results support the literature illustrating that the belief and expectation of analgesia induces discrete physiological changes, leading to relief from pain, and this response may be mediated by endogenous opioids. The implications of these findings are discussed in terms of the symbolic aspect of health care and mental health providers' words and context, and their potential impact on the course of illness and well-being.

Adult↗
PubMed2003

The contributions of suggestion, desire, and expectation to placebo effects in irritable bowel syndrome patients. An empirical investigation.

In order to investigate external factors that may influence the magnitude of placebo analgesia as well as psychological factors that mediate placebo analgesia, 13 irritable bowl syndrome (IBS) patients rated evoked rectal distension and cutaneous heat pain under the conditions of natural history (NH), rectal placebo (RP), rectal nocebo (RN), rectal lidocaine (RL) and oral lidocaine (OL). Patients were given verbal suggestions for pain relief and rated expected pain levels and desire for pain relief for both evoked visceral and cutaneous pain, respectively. Large reductions in pain intensity and pain unpleasantness ratings were found in the RP, RL and OL condition as compared to the natural history condition, whereas no significant difference in pain reduction between the three treatment conditions was found. Ratings during RN and NH were not statistically different. Compared to a previous study, which shows that rectal lidocaine reverses visceral and cutaneous hyperalgesia, these results suggest that adding a verbal suggestion for pain relief can increase the magnitude of placebo analgesia to that of an active agent. Since IBS patients rate these stimuli as much higher than do normal control subjects and since placebo effects were very large, they probably reflect anti-hyperalgesic mechanisms to a major extent. Expected pain levels and desire for pain relief accounted for large amounts of the variance in visceral pain intensity in the RP, RL, and OL condition (up to 81%), and for lower amounts of the variance in cutaneous pain intensity. Hence, the combination of expected pain levels and desire for pain relief may offer an alternative means of assessing the contribution of placebo factors during analgesia.

Administration, Oral↗
PubMed1999

Placebo effect in the treatment of duodenal ulcer.

AIMS: To assess whether frequency of placebo administration is associated with duodenal ulcer healing. METHODS: A systematic literature review of randomized clinical trials was undertaken. 79 of 80 trials that met the inclusion criteria. The pooled 4 week placebo healing rate of all duodenal ulcer trials that employed a four times a day regimen was compared with the rate obtained from trials with a twice a day regimen. RESULTS: The pooled 4 week healing rate of the 51 trials with a four times a day regimen was 44. 2% (805 of 1821 patients) compared with 36.2% (545 of 1504 patients) in the 28 trials with a twice a day regimen (difference, 8.0% [equal effects model]; 95% confidence interval, 4.6% to 11.3%). Depending on the statistical analysis, the rate difference ranged from 6.0% (multivariable random effects model) to 8.0% (equal effects model). A number of sensitivity analyses showed comparable differences between the two regimens. Most of these sensitivity analyses were not significant, probably because a number of trials were excluded resulting in a loss of power. CONCLUSIONS: We found a relation between frequency of placebo administration and healing of duodenal ulcer. We realize that the comparison was based on nonrandomized data. However, we speculate that the difference between regimens was induced by the difference in frequency of placebo administration. A better knowledge of various placebo effects is required in order to make clinically relevant assessments of treatment effects derived from placebo-controlled trials.

Duodenal Ulcer↗
PubMed2002

A quantification of the placebo response in migraine prophylaxis.

To quantify the placebo response of prophylactic therapy in migraine, a meta-analysis of prophylactic, double-blind, placebo controlled migraine studies was performed. The total analysis included 22 studies testing 19 different products, including 2013 patients, of which 828 were treated with placebo. A reduction in migraine attacks of 50% or more (responders) was seen in 23.5%+/-8.0 (95% C.I. 18.3-28.8%) of the patients in the placebo groups and 45.5%+/-15.5 (95% C.I. 37.4-53.6%) in the active groups. A reduction in migraine attacks of 16.8%+/-12.7 (95% C.I. 10.9-22.6%) was observed in the placebo groups and 41.8%+/-11.7 (95% C.I. 36.9-46.6%) in the active groups. We propose that if the percentage of responders in an open-label prophylactic trial in migraine is above 35-40%, or if a reduction in migraine attack frequency is found of 40% or more, further studies are indicated to determine the prophylactic activity of the drug. In all studies included in this analysis, no placebo response was seen above these limits.

Analgesics, Non-Narcotic↗
PubMed2007

Pacing for neurally mediated syncope: is placebo powerless?

BACKGROUND: After two recent controlled trials failed to prove superiority of cardiac pacing over placebo in patients affected by neurally mediated syncope, a widely accepted opinion is that cardiac pacing therapy is not very effective and that a strong placebo effect exists. AIM: To measure the effect of placebo pacing therapy. METHOD AND RESULTS: We compared the recurrence rate of syncope during placebo vs. no treatment in controlled trials of drug or pacing therapy. Syncope recurred in 38% of 252 patients randomized to placebo pooled from five trials vs. 34% of 881 patients randomized to no treatment pooled from eight trials. The corresponding recurrence rate with active cardiac pacing was 15% in 203 patients from six trials. CONCLUSIONS: Placebo is not an effective therapy for neurally mediated syncope. Different selection criteria in patients who are candidates for cardiac pacing-for example, presence, absence, or severity of the cardioinhibitory reflex may separate positive from negative trials.

Follow-Up Studies↗