A double blind placebo controlled crossover study of prostacyclin in man.

Prostacyclin sodium (PGI₂) was administered in a double blind crossover trial to 6 normal males at infusion rates of 2, 4 and 8 ng/kg/minute. Substantial (p < 0.001) shifts of the log dose response curve of ADP induced platelet aggregation occured during the highest infusion rate of PGI₂. This was associated with a small but significant fall in diastolic blood pressure (?6.3± 1.6 mm Hg, p < 0.01) and a rise in heart rate (+25.5 ± 6.5 beats/minute, p < 0.001). Plasma renin activity rose in a dose related manner with PGI₂ but plasma aldosterone and plasma norepinephrine did not change. Marked facial flushing occured with PGI₂.     

Omeprazole versus placebo for acute upper gastrointestinal bleeding: randomised double blind controlled trial.

OBJECTIVE--To investigate the possible therapeutic role of omeprazole, a powerful proton pump inhibitor, in unselected patients presenting with upper gastrointestinal bleeding. DESIGN--Double blind placebo controlled parallel group study. Active treatment was omeprazole 80 mg intravenously immediately, then three doses of 40 mg intravenously at eight hourly intervals, then 40 mg orally at 12 hourly intervals. Treatment was started within 12 hours of admission and given for four days or until surgery, discharge, or death. SETTING--The medical wards of University and City Hospitals, Nottingham. SUBJECTS--1147 consecutive patients aged 18 years or more admitted over 40 months with acute upper gastrointestinal bleeding. MAIN OUTCOME MEASURES--Mortality from all causes; rate of rebleeding, transfusion requirements, and operation rate; effect of treatment on endoscopic appearances at initial endoscopy. RESULTS--Of 1147 patients included in the intention to treat analysis, 569 received placebo and 578 omeprazole. No significant differences were found between the placebo and omeprazole groups for rates of transfusion (302 (53%) placebo v 298 (52%) omeprazole), rebleeding (100 (18%) v 85 (15%)), operation (63 (11%) v 62 (11%)), and death (30 (5.3%) v 40 (6.9%)). However, there was an unexpected but significant reduction in endoscopic signs of upper gastrointestinal bleeding in patients treated with omeprazole compared with those treated with placebo (236 (45%) placebo v 176 (33%) omeprazole; p less than 0.0001). CONCLUSIONS--Omeprazole failed to reduce mortality, rebleeding, or transfusion requirements, although the reduction in endoscopic signs of bleeding suggests that inhibition of acid may be capable of influencing intragastric bleeding. Our data do not justify the routine use of acid inhibiting drugs in the management of haematemesis and melaena.     

Acyclovir given as prophylaxis against oral ulcers in acute myeloid leukaemia: randomised,double blind,placebo controlled trial.

OBJECTIVES--To evaluate (a) the prophylactic effect of the antiherpetic drug acyclovir on oral ulcers in patients with acute myeloid leukaemia receiving remission induction chemotherapy and thus (b), indirectly, the role of herpes simplex virus in the aetiology of these ulcers. DESIGN--Randomised, double blind, placebo controlled trial. SUBJECTS--74 herpes simplex virus seropositive patients aged 18-84. Thirty seven patients received acyclovir (800 mg by mouth daily) and 37 placebo. The patients were examined daily for 28 days. MAIN OUTCOME MEASURES--Occurrence of herpes labialis, intraoral ulcers, and acute necrotising ulcerative gingivitis. RESULTS--The two populations were comparable in age, sex, type of antineoplastic treatment, and history of herpes labialis. Acute oral infections occurred in 25 of the acyclovir treated patients and 36 of the placebo treated patients (relative risk 0.69 (95% confidence interval 0.55 to 0.87)). This difference was due to a reduction in the incidence of herpes labialis (one case versus eight cases; relative risk 0.13 (0.02 to 0.95)), intraoral ulcers excluding the soft palate (one case versus 13 cases; relative risk 0.08 (0.01 to 0.56)), and acute necrotising ulcerative gingivitis (one case versus eight cases; relative risk 0.13 (0.02 to 0.95)). However, ulcers on the soft palate were diagnosed with similar frequency in the two groups. Isolation of herpes simplex virus type 1 in saliva was reduced from 15 cases in the placebo group to one case in the acyclovir group (relative risk 0.07 (0.01 to 0.48)). CONCLUSION--Intraoral ulcers excluding the soft palate are most often due to infection with herpes simplex virus, whereas ulcers on the soft palate have a non-herpetic aetiology. The findings suggest that acute necrotising ulcerative gingivitis may also be due to herpes simplex virus. Prophylaxis with acyclovir should be considered for patients with acute myeloid leukaemia during remission induction therapy.     

Diagnostic utility of flumazenil in coma with suspected poisoning: a double blind,randomised controlled study.

OBJECTIVE--To assess the diagnostic value and safety of the benzodiazepine antagonist flumazenil in patients with coma of unclear origin with suspected poisoning. DESIGN--Double blind, placebo controlled, randomised study. SETTING--Intensive care unit at a major teaching hospital. PATIENTS--105 Unconscious adults admitted consecutively with suspected drug overdosage during 18 months from a total of 362 cases of poisoning. Exclusion criteria were pregnancy, epilepsy, obvious poisoning with drugs identified unequivocally from information from relatives or others as other than benzodiazepines, and coma score greater than 10 on a scale graded from 4 to 20. Patients were allocated randomly to receive flumazenil (21 men and 32 women) or placebo (25 men and 27 women). INTERVENTIONS--Intravenous injection of flumazenil (10 ml, 0.1 mg/ml) or placebo (10 ml vehicle alone) given double blind over three minutes. MAIN OUTCOME MEASURES--Serum and urine concentrations of benzodiazepines, antidepressants, and several other agents; blood gas tensions; standardised evaluation on admission and five minutes after the injection by means of coma scale score and urgent diagnostic or therapeutic interventions indicated according to the history and clinical examination; standardised interview after the injection to try to ascertain further information; and adverse reactions. RESULTS--Benzodiazepines were found in the serum in 36 of the 53 patients in the flumazenil group and in 37 of the 52 who received placebo. The average coma scale score increased significantly after injection in the flumazenil group (6.4 v 12.1, p less than 0.001) but not in the placebo group. In the flumazenil group several interventions were rendered unnecessary by the injection: gastric lavage and urinary catheterisation (19 patients each), intubation (21), artificial ventilation and computed tomography of the brain (three patients each), blood culture and lumbar puncture (one patient each), and electroencephalography (two). In the placebo group the indications for these procedures did not change in any patient after injection. The 95% confidence interval for the difference in reduction of the frequency of indications for gastric lavage after injection between the two groups was 21% to 51%, that for intubation 25% to 55%, and that for urinary catheterisation 21% to 51%. In the flumazenil group 21 patients gave valuable information on their drug ingestion within 10 minutes after injection compared with only one in the placebo group (p less than 0.001). Nine adverse reactions were recorded in the flumazenil group, eight of which were graded as mild and one severe. The safety of the antagonist was acceptable, even though 60% of the patients in the flumazenil group had multiple drug poisoning including benzodiazepine. No epileptic seizures or arrhythmias were recorded. CONCLUSION--Flumazenil is a valuable and safe differential diagnostic tool in unclear cases of multiple drug poisoning.     

Effectiveness of Ginkgo biloba in treating tinnitus: double blind, placebo controlled trial

ObjectiveTo determine whether Ginkgo biloba is effective in treating tinnitus.DesignDouble blind, placebo controlled trial using postal questionnaires.Participants1121 healthy people aged between 18 and 70 years with tinnitus that was comparatively stable; 978 participants were matched (489 pairs).Intervention12 weeks'' treatment with either 50 mg Ginkgo biloba extract LI 1370 three times daily or placebo.ResultsThere were no significant differences in primary or secondary outcome measures between the groups. 34 of 360 participants receiving active treatment reported that their tinnitus was less troublesome after 12 weeks of treatment compared with 35 of 360 participants who took placebo.Conclusions50 mg Ginkgo biloba extract LI 1370 given 3 times daily for 12 weeks is no more effective than placebo in treating tinnitus.     

Lidocaine patch (5%) is no more potent than placebo in treating chronic back pain when tested in a randomised double blind placebo controlled brain imaging study

ABSTRACT: The 5% Lidocaine patch is used for treating chronic neuropathic pain conditions such as chronic back pain (CBP), diabetic neuropathy and complex regional pain syndrome, but is effective in a variable proportion of patients. Our lab has reported that this treatment reduces CBP intensity and associated brain activations when tested in an open labelled preliminary study. Notably, effectiveness of the 5% Lidocaine patch has not been tested against placebo for treating CBP. In this study, effectiveness of the 5% Lidocaine patch was compared with placebo in 30 CBP patients in a randomised double-blind study where 15 patients received 5% Lidocaine patches and the remaining patients received placebo patches. Functional MRI was used to identify brain activity for fluctuations of spontaneous pain, at baseline and at two time points after start of treatment (6 hours and 2 weeks). There was no significant difference between the treatment groups in either pain intensity, sensory and affective qualities of pain or in pain related brain activation at any time point. However, 50% patients in both the Lidocaine and placebo arms reported a greater than 50% decrease in pain suggesting a marked placebo effect. When tested against an untreated CBP group at similar time points, the patch treated subjects showed significantly greater decrease in pain compared to the untreated group (n=15). These findings suggest that although the 5% Lidocaine is not better than placebo in its effectiveness for treating pain, the patch itself induces a potent placebo effect in a significant proportion of CBP patients.     

Topical treatment of erectile dysfunction: randomised double blind placebo controlled trial of cream containing aminophylline,isosorbide dinitrate,and co-dergocrine mesylate.

OBJECTIVE--To examine the effectiveness in treating impotence to topically applied cream containing three vasodilators--aminophylline, isosorbide dinitrate, and co-dergocrine mesylate--which act by different mechanisms. DESIGN--Randomised double blinded placebo controlled crossover trial over two weeks. SUBJECTS--36 men with erectile dysfunction randomly allocated to two equal groups. INTERVENTIONS--Active cream containing aminophylline 3%, isosorbide dinitrate 0.25%, and co-dergocrine mesylate 0.05% for one week and placebo for another. MAIN OUTCOME MEASURES--Patients'' reported experience of penile responses and side effects of treatment in questionnaires. Penile tumescence and arterial flow in the laboratory. RESULTS--21 patients reported full erection and satisfactory intercourse with the active cream. Three men reported full erection and satisfactory intercourse with either cream. The active cream was more effective in psychogenic than organic impotence (eight out of nine men with psychogenic impotence achieved a full erection upsilon four out of eight with neurogenic impotence and two out of seven with arterial insufficiency). No major side effects were reported. In the laboratory the active cream increased penile arterial flow (0.19 (SD 0.08) m/s upsilon 0.02 (0.15) m/s with placebo) and induced tumescence in 24 patients. CONCLUSIONS--Topical treatment with a cream containing three different vasodilators might be considered before intracavernous injection of vasoactive agents, particularly in psychogenic impotence.     

Effect of inhaled corticosteroids on episodes of wheezing associated with viral infection in school age children: randomised double blind placebo controlled trial.

OBJECTIVES: To determine the effect of regular prophylactic inhaled corticosteroids on wheezing episodes associated with viral infection in school age children. DESIGN: Randomised, double blind, placebo controlled trial. SETTING: Community based study in Southampton. SUBJECTS: 104 children aged 7 to 9 years who had had wheezing in association with symptoms of upper and lower respiratory tract infection in the preceding 12 months. INTERVENTIONS: After a run in period of 2-6 weeks children were randomly allocated twice daily inhaled beclomethasone dipropionate 200 micrograms or placebo through a Diskhaler for 6 months with a wash out period of 2 months. Children were assessed monthly. MAIN OUTCOME MEASURES: Forced expiratory volume in 1 second (FEV1); bronchial responsiveness to methacholine (PD20); percentage of days with symptoms of upper and lower respiratory tract infection with frequency, severity, and duration of episodes of upper and lower respiratory symptoms and of reduced peak expiratory flow rate. RESULTS: During the treatment period there was a significant increase in mean FEV1 (1.63 v 1.53 1; adjusted difference 0.09 1 (95% confidence interval 0.04 to 0.14); P = 0.001) and methacholine PD20 12.8 v 7.2 mumol/l; adjusted ratio of means 1.7 (1.2 to 2.4); P = 0.007) in children receiving beclomethasone dipropionate compared with placebo. There were, however, no significant differences in the percentage of days with symptoms or in the frequency, severity, or duration of episodes of upper or lower respiratory symptoms or of reduced peak expiratory flow rate during the treatment period between the two groups. CONCLUSIONS: Although lung function is improved with regular beclomethasone dipropionate 400 micrograms/day, this treatment offers no clinically significant benefit in school age children with wheezing episodes associated with viral infection.     

Randomised,double blind placebo controlled trial of pentoxifylline in the treatment of venous leg ulcers

ObjectiveTo determine whether pentoxifylline 400 mg (Trental 400) taken orally three times daily, in addition to ambulatory compression bandages and dressings, improves the healing rate of pure venous ulcers.DesignRandomised, double blind placebo controlled trial, parallel group study of factorial design, permitting the simultaneous evaluation of alternative pharmaceutical, bandaging, and dressings materials.SettingLeg ulcer clinics of a teaching and a district general hospital in southern Scotland.Participants200 patients with confirmed venous ulcers and in whom other major causal factors were excluded.InterventionsPentoxifylline 400 mg three times daily or placebo.ResultsComplete healing occurred in 65 of the 101 (64%) patients receiving pentoxifylline and 52 of the 99 (53%) patients receiving placebo.ConclusionsThe difference in the healing rates between patients taking pentoxifylline and those taking placebo did not reach statistical significance.

Key messages

• Leg ulcers cost the NHS around £400 million per annum
• 50%-75% of venous leg ulcers can be succesfully treated with dressings and compression bandages but take many months to heal
• A drug that reduced the healing time of venous ulcers would be useful, although no agent has been proved to be effective to date
• Trials with pentoxifylline, a vasoactive drug used in the treatment of peripheral vascular diseases, as an adjunct to the treatment of venous ulcers have been inconclusive
• At the 5% level, pentoxifylline had a non-significant effect on healing rates of pure venous ulcers

     

Zinc supplementation during pregnancy: a double blind randomised controlled trial.

OBJECTIVE--To see whether zinc supplementation during pregnancy improves maternal and fetal outcome. DESIGN--Prospective study started at booking and continued till discharge of mother and baby from the maternity hospital. Mothers were randomly assigned to receive zinc supplementation or placebo in a double blind trial. SETTING--Mothers booking at one hospital. PATIENTS--Women booking before 20 weeks of gestation who agreed to take part in the study. 494 Mothers were followed up till the end of pregnancy. There was no difference between the groups given zinc and placebo in their social or medical backgrounds. INTERVENTIONS--Mothers in the active treatment group received one capsule of 20 mg elemental zinc daily and those in the placebo treated group a capsule identical in appearance and taste with the active capsule but which contained inert substances. MAIN OUTCOME MEASURE--Various adverse outcomes were tested, including maternal bleeding, hypertension, complications of labour and delivery, gestational age, Apgar scores, and neonatal abnormalities. The main outcome measure was birth weight. RESULTS--There were no differences whatsoever between mothers given a zinc supplement and those given a placebo. CONCLUSION--Zinc supplementation in pregnancy in the United Kingdom does not seem to offer any benefits to the mother or her fetus.     

Reversal of postmenopausal vertebral bone loss by oestrogen and progestogen: a double blind placebo controlled study

Because of uncertainty about the place of hormones in the treatment of postmenopausal bone loss vertebral and forearm bone loss was measured by absorptiometry in early post-menopausal women before and after continuous or sequential treatment with combined oestrogen and progestogen in a double blind placebo controlled trial. Treatment with hormones significantly reversed the vertebral bone loss. The net gain in vertebral bone density amounted to 6·4% a year with continuous supplementation and 5·4% a year with sequential supplementation; the net gain in forearm bone density was lower (3·6% with continuous and 3·7% with sequential supplementation).Before a policy of supplementation with hormones can be recommended to all postmenopausal women with the aim of reducing the incidence of vertebral crush fractures further studies with different doses and combinations of hormones, administered over several years, are needed.     

Salmeterol in nocturnal asthma: a double blind,placebo controlled trial of a long acting inhaled beta 2 agonist.

OBJECTIVE--To determine whether inhaled salmeterol, a new long acting inhaled beta adrenergic agonist, reduces nocturnal bronchoconstriction and improves sleep quality in patients with nocturnal asthma. DESIGN--Randomised, double blind, placebo controlled crossover study. SETTING--Hospital outpatient clinics in Edinburgh. SUBJECTS--Twenty clinically stable patients (13 women, seven men) with nocturnal asthma, median age 39 (range 18-60) years. INTERVENTIONS--Salmeterol 50 micrograms and 100 micrograms and placebo taken each morning and evening by metered dose inhaler. Rescue salbutamol inhalers were provided throughout the run in and study periods. MAIN OUTCOME MEASURES--Improvement in nocturnal asthma as measured by peak expiratory flow rates and change in sleep quality as measured by electroencephalography. RESULTS--Salmeterol improved the lowest overnight peak flow rate at both 50 micrograms (difference in median values (95% confidence interval for difference in medians) 69 (18 to 88) l/min) and 100 micrograms (72 (23 to 61) l/min) doses twice daily. While taking salmeterol 50 micrograms twice daily patients had an objective improvement in sleep quality, spending less time awake or in light sleep (-9 (-4 to -44) min) and more time in stage 4 sleep (26 (6-34) min). CONCLUSIONS--Salmeterol is an effective long acting inhaled bronchodilator for patients with nocturnal asthma and at a dose of 50 micrograms twice daily improves objective sleep quality.     

A double blind placebo controlled trial of intravenous prostacyclin (PGI2) in 108 patients with ischaemic peripheral vascular disease

108 patients with ischemic peripheral vascular disease were randomly allocated to receive infusion of either PGI2 (6 ng/kg/min over 8 hours daily for 5 consecutive days) or placebo in a double-blind manner. All patients had Stage II disease (Fontaine classification). One month after infusion the absolute and relative walking times were significantly (p less than 0.05) longer in the PGI2- than in the placebo-treated group. Patients were further classified as treatment responders or non-responders on the basis of increase of absolute and relative walking times. After one month 44% (24 out of 54) of the PGI2- and 15% (8 out of 54) of the placebo-treated patients were positive treatment-responders (p less than 0.01).     

Randomised,double blind,placebo controlled clinical trial of efficacy of vitamin A treatment in non-measles childhood pneumonia.

OBJECTIVE: To evaluate the impact on clinical recovery and severity of the addition of large doses of vitamin A to the standard treatment for childhood pneumonia. DESIGN: A randomised, double blind, placebo controlled trial. SETTING: Study children were recruited at a public hospital in Recife, north east Brazil, an area of marginal vitamin A deficiency. SUBJECTS: 472 children aged 6 to 59 months with clinical diagnosis of pneumonia. INTERVENTIONS: 200,000 IU (infants) or 400,000 IU (1-4 year olds) of vitamin A in oil or similar capsules of placebo divided into two daily oral doses, in addition to the standard treatment. MAIN OUTCOME MEASURES: Duration of the episode and incidence of adverse outcomes. RESULTS: The groups were similar with respect to overall duration of pneumonia and incidence of adverse outcomes. Children who received vitamin A, however, were less likely to have fever by day 3 (P = 0.008) and were 29% less likely to fail to respond to the first line antibiotic (P = 0.054). CONCLUSION: There was little evidence for an effect of vitamin A treatment on the immediate outcome of the pneumonia episode.     

Randomised,double blind,placebo controlled crossover trial of sustained release morphine for the management of refractory dyspnoea

Objective To determine the efficacy of oral morphine in relieving the sensation of breathlessness in patients in whom the underlying aetiology is maximally treated.Design Randomised, double blind, placebo controlled crossover study.Setting Four outpatient clinics at a hospital in South Australia.Participants 48 participants who had not previously been treated with opioids (mean age 76, SD 5) with predominantly chronic obstructive pulmonary disease (42, 88%) were randomised to four days of 20 mg oral morphine with sustained release followed by four days of identically formulated placebo, or vice versa. Laxatives were provided as needed.Main outcome measures Dyspnoea in the morning and evening as shown on a 100 mm visual analogue scale, quality of sleep, wellbeing, performance on physical exertion, and side effects as measured at the end of the four day treatment period.Results 38 participants completed the study; three withdrew because of definite and two because of possible side effects of morphine (nausea, vomiting, and sedation). Participants reported significantly different dyspnoea scores when treated with morphine: an improvement of 6.6 mm (95% confidence interval 1.6 mm to 11.6 mm) in the morning and of 9.5 mm (3.0 mm to 16.1 mm) in the evening (P = 0.011 and P = 0.006, respectively). During the period in which they were taking morphine participants also reported better sleep (P = 0.039). More participants reported distressing constipation while taking morphine (9 v 1, P = 0.021) in spite of using laxatives. All other side effects were not significantly worse with morphine, although the study was not powered to address side effects.Conclusions Sustained release, oral morphine at low dosage provides significant symptomatic improvement in refractory dyspnoea in the community setting.