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The Cochrane Database of Systematic... Feb 2010Otitis media (inflammation of the middle ear, usually caused by infection) affects people of all ages, but is particularly common in young children. Around 164 million... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Otitis media (inflammation of the middle ear, usually caused by infection) affects people of all ages, but is particularly common in young children. Around 164 million people worldwide have long-term hearing loss caused by this condition, 90% of them in low-income countries. Because zinc supplements prevent pneumonia in disadvantaged children, we wondered whether they prevent otitis media.
OBJECTIVES
To evaluate whether zinc supplements prevent otitis media in adults and children of different ages.
SEARCH STRATEGY
We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, issue 2) which includes the Acute Respiratory Infection Groups' Specialised Register; MEDLINE (1950 to June Week 1 2009); and EMBASE (1974 to June 2009).
SELECTION CRITERIA
Randomised, placebo-controlled trials of zinc supplements given at least once a week for at least a month for preventing otitis media.
DATA COLLECTION AND ANALYSIS
Two review authors assessed the eligibility and methodological quality of the included trials, extracted and analysed data and wrote the review. We summarised results using risk ratios or rate ratios for dichotomous data and mean differences for continuous data. We combined trial results where appropriate.
MAIN RESULTS
We identified 12 trials for inclusion, 10 of which contributed outcomes data. In trials of healthy children living in low-income communities, two trials did not demonstrate a significant difference between the zinc supplemented and placebo groups in the numbers of participants experiencing an episode of definite otitis media during follow up (3191 participants), while another trial showed a significantly lower incidence rate of otitis media in the zinc group (rate ratio 0.69, 95% confidence interval (CI) 0.61 to 0.79, n = 1621). A small trial of 39 infants undergoing treatment for severe malnutrition suggested a benefit of zinc on the mean number of episodes of otitis media (mean difference -1.12 episodes, 95% CI -2.21 to -0.03). Zinc supplements did not seem to cause any serious adverse events, but a small minority of children were reported to have vomited shortly after ingestion of the supplements.
AUTHORS' CONCLUSIONS
Evidence on whether zinc supplementation can reduce the incidence of otitis media in healthy children under the age of five years living in low- and middle-income countries is mixed. There is some evidence of benefit in children being treated for marasmus, but this is based on one small trial and should therefore be treated with caution.
Topics: Child, Preschool; Chlorides; Developing Countries; Dietary Supplements; Female; Gluconates; Humans; Infant; Male; Otitis Media; Randomized Controlled Trials as Topic; Trace Elements; Zinc Acetate; Zinc Compounds; Zinc Sulfate
PubMed: 20166086
DOI: 10.1002/14651858.CD006639.pub2 -
The Cochrane Database of Systematic... Mar 2016Sickle cell disease is an inherited disorder of hemoglobin, resulting in abnormal red blood cells. These are rigid and may block blood vessels leading to acute painful... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Sickle cell disease is an inherited disorder of hemoglobin, resulting in abnormal red blood cells. These are rigid and may block blood vessels leading to acute painful crises and other complications. Recent research has focused on therapies to rehydrate the sickled cells by reducing the loss of water and ions from them. Little is known about the effectiveness and safety of such drugs. This is an updated version of a previously published review.
OBJECTIVES
To assess the relative risks and benefits of drugs to rehydrate sickled red blood cells.
SEARCH METHODS
We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register.Last search of the Group's Trials Register: 28 November 2015.
SELECTION CRITERIA
Randomized or quasi-randomized controlled trials of drugs to rehydrate sickled red blood cells compared to placebo or an alternative treatment.
DATA COLLECTION AND ANALYSIS
Both authors independently selected studies for inclusion, assessed study quality and extracted data.
MAIN RESULTS
Of the 51 studies identified, three met the inclusion criteria. The first study tested the effectiveness of zinc sulphate to prevent sickle cell-related crises in a total of 145 participants and showed a significant reduction in painful crises over one and a half years, mean difference -2.83 (95% confidence interval -3.51 to -2.15). However, analysis was restricted due to limited statistical data. Changes to red cell parameters and blood counts were inconsistent. No serious adverse events were noted in the study.The second study was a Phase II dose-finding study of senicapoc (a Gardos channel blocker) compared to placebo. Compared to the placebo group the high dose senicapoc showed significant improvement in change in hemoglobin level, number and proportion of dense red blood cells, red blood cell count and indices and hematocrit. The results with low-dose senicapoc were similar to the high-dose senicapoc group but of lesser magnitude. There was no difference in the frequency of painful crises between the three groups. A subsequent Phase III study of senicapoc was terminated early since there was no difference observed between the treatment and control groups in the primary end point of painful crises.
AUTHORS' CONCLUSIONS
While the results of zinc for reducing sickle-related crises are encouraging, larger and longer-term multicenter studies are needed to evaluate the effectiveness of this therapy for people with sickle cell disease.While the Phase II and the prematurely terminated phase III studies of senicapoc showed that the drug improved red cell survival (depending on dose), this did not lead to fewer painful crises.We will continue to run searches to identify any potentially relevant trials; however, we do not plan to update other sections of the review until new trials are published.
Topics: Acetamides; Anemia, Sickle Cell; Antisickling Agents; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Dehydration; Early Termination of Clinical Trials; Erythrocyte Aging; Erythrocytes; Humans; Piracetam; Randomized Controlled Trials as Topic; Trityl Compounds; Zinc Sulfate
PubMed: 26942338
DOI: 10.1002/14651858.CD003426.pub5 -
International Forum of Allergy &... Jul 2016Postviral olfactory dysfunction (PVOD) is the most common cause of olfactory dysfunction. Several treatments have been presented in the literature. The objective of this... (Review)
Review
BACKGROUND
Postviral olfactory dysfunction (PVOD) is the most common cause of olfactory dysfunction. Several treatments have been presented in the literature. The objective of this study is to systematically review the existing literature on the effectiveness of pharmacologic treatments for PVOD.
METHODS
We performed a literature search of PubMed, Ovid, and ScienceDirect from 1966 to 2014. Inclusion criteria included English-language articles containing original data on pharmacologic treatment of PVOD with ≥5 subjects, measurable outcomes, and readily available treatments. Data was collected regarding study design, subject demographic information, clinical outcomes, and level of evidence. Two investigators reviewed all articles independently.
RESULTS
Of 445 abstracts identified, 8 articles were included, yielding 563 patients. Treatments investigated included oral corticosteroids, local injections of corticosteroids, zinc sulfate, alpha lipoic acid, caroverine, vitamin A, Ginkgo biloba, and minocycline. Outcome measures were determined by symptom scores and objective olfactory test methods-the most common being Sniffin' Sticks. Improvement was noted in subjects receiving oral corticosteroid therapy, local injections of corticosteroid, alpha lipoic acid, and caroverine, whereas vitamin A, zinc sulfate, Ginkgo biloba, and minocycline groups did not show significant improvement.
CONCLUSION
The majority of therapies investigated that show benefit in treating PVOD are of poor quality. Although caroverine therapy showed benefit and is a level 1b study, etiologies of olfactory dysfunction other than PVOD were included as well, which clouds the results. Overall, there is no strong evidence for any pharmacologic treatment of PVOD in the literature.
Topics: Adrenal Cortex Hormones; Ginkgo biloba; Humans; Minocycline; Olfaction Disorders; Quinoxalines; Thioctic Acid; Vitamin A; Zinc Sulfate
PubMed: 26879592
DOI: 10.1002/alr.21727 -
The Cochrane Database of Systematic... Aug 2012Leg ulcers affect up to one percent of people at some time in their life. Leg ulceration is chronic in nature with ulcers being present for months and in some cases... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Leg ulcers affect up to one percent of people at some time in their life. Leg ulceration is chronic in nature with ulcers being present for months and in some cases years without healing, and with a high risk of recurrence. Management approaches include dressings and the treatment of underlying medical problems such as malnutrition, lack of minerals and vitamins, poor blood supply or infection.
OBJECTIVES
To assess the effectiveness of oral zinc in healing arterial or venous leg ulcers.
SEARCH METHODS
For this sixth update we searched The Cochrane Wounds Group Specialised Register (searched 17 May 2012); The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 5); Ovid MEDLINE (2010 to May Week 2 2012); Ovid MEDLINE (In-Process & Other Non-Indexed Citations May 16, 2012); Ovid EMBASE (2010 to 2012 Week 19); and EBSCO CINAHL (2010 to May 2 2012). In the original version of the review a company manufacturing zinc sulphate tablets was asked for references to relevant trials.
SELECTION CRITERIA
Randomised controlled trials comparing oral zinc sulphate with placebo or no treatment in people with arterial or venous leg ulcers were eligible for inclusion. There were no restrictions on date or language of publication. The main outcome measure used was complete healing of the ulcers. Trials were eligible for inclusion if they measured ulcer healing objectively by documenting time to complete healing, proportion of ulcers healed during the study, or healing rates of ulcers.
DATA COLLECTION AND ANALYSIS
All data extraction and assessment of trial quality were done by both authors independently.
MAIN RESULTS
Six small trials (183 participants) were eligible for inclusion. Four trials considered people with venous ulcers, one trial arterial ulcers and one people with mixed ulcers. In four trials, serum zinc was measured at baseline or during the trial. Pooling the four trials that compared oral zinc sulphate with placebo in people with venous ulcers showed no statistically significant difference between the two group (RR 1.22, 95%CI 0.88 to 1.68). Overall, there was no evidence of a beneficial effect of treatment with zinc sulphate on the number of ulcers healed.
AUTHORS' CONCLUSIONS
Oral zinc sulphate does not appear to aid healing of arterial and venous leg ulcers, however all included studies were small and of mediocre quality.
Topics: Administration, Oral; Astringents; Humans; Leg Ulcer; Randomized Controlled Trials as Topic; Zinc; Zinc Sulfate
PubMed: 22895918
DOI: 10.1002/14651858.CD001273.pub2 -
The Cochrane Database of Systematic... Jul 2012Sickle cell disease is an inherited disorder of hemoglobin, resulting in abnormal red blood cells. These are rigid and may block blood vessels leading to acute painful... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Sickle cell disease is an inherited disorder of hemoglobin, resulting in abnormal red blood cells. These are rigid and may block blood vessels leading to acute painful crises and other complications. Recent research has focused on therapies to rehydrate the sickled cells by reducing the loss of water and ions from them. Little is known about the effectiveness and safety of such drugs.
OBJECTIVES
To assess the relative risks and benefits of drugs to rehydrate sickled red blood cells.
SEARCH METHODS
We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register.Last search of the Group's Trials Register: 25 October 2011.
SELECTION CRITERIA
Randomized or quasi-randomized controlled trials of drugs to rehydrate sickled red blood cells compared to placebo or an alternative treatment.
DATA COLLECTION AND ANALYSIS
Both authors independently selected studies for inclusion, assessed study quality and extracted data.
MAIN RESULTS
Of the 51 studies identified, three met the inclusion criteria. The first study tested the effectiveness of zinc sulphate to prevent sickle cell-related crises in a total of 145 participants and showed a significant reduction in painful crises over one and a half years, mean difference -2.83 (95% confidence interval -3.51 to -2.15). However, analysis was restricted due to limited statistical data. Changes to red cell parameters and blood counts were inconsistent. No serious adverse events were noted in the study.The second study was a Phase II dose-finding study of senicapoc (a Gardos channel blocker) compared to placebo. Compared to the placebo group the high dose senicapoc showed significant improvement in change in hemoglobin level, number and proportion of dense red blood cells, red blood cell count and indices and hematocrit. The results with low-dose senicapoc were similar to the high-dose senicapoc group but of lesser magnitude. There was no difference in the frequency of painful crises between the three groups. A subsequent Phase III study of senicapoc was terminated early since there was no difference observed between the treatment and control groups in the primary end point of painful crises.
AUTHORS' CONCLUSIONS
While the results of zinc for reducing sickle-related crises are encouraging, larger and longer-term multicenter studies are needed to evaluate the effectiveness of this therapy for people with sickle cell disease.While the Phase II and the prematurely terminated phase III studies of senicapoc showed that the drug improved red cell survival (depending on dose), this did not lead to fewer painful crises.
Topics: Acetamides; Anemia, Sickle Cell; Antisickling Agents; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Dehydration; Early Termination of Clinical Trials; Erythrocyte Aging; Erythrocytes; Humans; Piracetam; Randomized Controlled Trials as Topic; Trityl Compounds; Zinc Sulfate
PubMed: 22786485
DOI: 10.1002/14651858.CD003426.pub4 -
The Cochrane Database of Systematic... Sep 2022Loss of olfactory function is well recognised as a symptom of COVID-19 infection, and the pandemic has resulted in a large number of individuals with abnormalities in... (Review)
Review
BACKGROUND
Loss of olfactory function is well recognised as a symptom of COVID-19 infection, and the pandemic has resulted in a large number of individuals with abnormalities in their sense of smell. For many, the condition is temporary and resolves within two to four weeks. However, in a significant minority the symptoms persist. At present, it is not known whether early intervention with any form of treatment (such as medication or olfactory training) can promote recovery and prevent persisting olfactory disturbance. This is an update of the 2021 review with four studies added.
OBJECTIVES
1) To evaluate the benefits and harms of any intervention versus no treatment for people with acute olfactory dysfunction due to COVID-19 infection. 2) To keep the evidence up-to-date, using a living systematic review approach. SEARCH METHODS: The Cochrane ENT Information Specialist searched the Cochrane ENT Register; Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid Embase; Web of Science; ClinicalTrials.gov; ICTRP and additional sources for published and unpublished trials. The date of the latest search was 20 October 2021.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) in people with COVID-19 related olfactory disturbance, which had been present for less than four weeks. We included any intervention compared to no treatment or placebo. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were the presence of normal olfactory function, serious adverse effects and change in sense of smell. Secondary outcomes were the prevalence of parosmia, change in sense of taste, disease-related quality of life and other adverse effects (including nosebleeds/bloody discharge). We used GRADE to assess the certainty of the evidence for each outcome. MAIN RESULTS: We included five studies with 691 participants. The studies evaluated the following interventions: intranasal corticosteroid sprays, intranasal corticosteroid drops, intranasal hypertonic saline and zinc sulphate. Intranasal corticosteroid spray compared to no intervention/placebo We included three studies with 288 participants who had olfactory dysfunction for less than four weeks following COVID-19. Presence of normal olfactory function The evidence is very uncertain about the effect of intranasal corticosteroid spray on both self-rated recovery of olfactory function and recovery of olfactory function using psychophysical tests at up to four weeks follow-up (self-rated: risk ratio (RR) 1.19, 95% confidence interval (CI) 0.85 to 1.68; 1 study; 100 participants; psychophysical testing: RR 2.3, 95% CI 1.16 to 4.63; 1 study; 77 participants; very low-certainty evidence). Change in sense of smell The evidence is also very uncertain about the effect of intranasal corticosteroid spray on self-rated change in the sense of smell (at less than 4 weeks: mean difference (MD) 0.5 points lower, 95% CI 1.38 lower to 0.38 higher; 1 study; 77 participants; at > 4 weeks to 3 months: MD 2.4 points higher, 95% CI 1.32 higher to 3.48 higher; 1 study; 100 participants; very low-certainty evidence, rated on a scale of 1 to 10, higher scores mean better olfactory function). Intranasal corticosteroids may make little or no difference to the change in sense of smell when assessed with psychophysical testing (MD 0.2 points, 95% CI 2.06 points lower to 2.06 points higher; 1 study; 77 participants; low-certainty evidence, 0- to 24-point scale, higher scores mean better olfactory function). Serious adverse effects The authors of one study reported no adverse effects, but their intention to collect these data was not pre-specified so we are uncertain if these were systematically sought and identified. The remaining two studies did not report on adverse effects. Intranasal corticosteroid drops compared to no intervention/placebo We included one study with 248 participants who had olfactory dysfunction for ≤ 15 days following COVID-19. Presence of normal olfactory function Intranasal corticosteroid drops may make little or no difference to self-rated recovery at > 4 weeks to 3 months (RR 1.00, 95% CI 0.89 to 1.11; 1 study; 248 participants; low-certainty evidence). No other outcomes were assessed by this study. Data on the use of hypertonic saline nasal irrigation and the use of zinc sulphate to prevent persistent olfactory dysfunction are included in the full text of the review.
AUTHORS' CONCLUSIONS
There is very limited evidence available on the efficacy and harms of treatments for preventing persistent olfactory dysfunction following COVID-19 infection. However, we have identified a number of ongoing trials in this area. As this is a living systematic review we will update the data regularly, as new results become available.
Topics: Adrenal Cortex Hormones; COVID-19; Chronic Disease; Humans; Olfaction Disorders; Randomized Controlled Trials as Topic; Rhinitis; Smell; Zinc Sulfate
PubMed: 36063364
DOI: 10.1002/14651858.CD013877.pub3 -
Nutrition, Metabolism, and... Jul 2020Findings on the effects of zinc supplementation on the lipid profile in patients with type 2 diabetes mellitus (T2DM) are conflicting. The current comprehensive... (Meta-Analysis)
Meta-Analysis
BACKGROUND AND AIM
Findings on the effects of zinc supplementation on the lipid profile in patients with type 2 diabetes mellitus (T2DM) are conflicting. The current comprehensive systematic review and meta-analysis aimed to summarize available evidence in this regard.
METHODS AND RESULTS
After a systematic search in the online databases, we included the randomized controlled trials (RCTs) investigating the effect of zinc supplementation on lipid profile [total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TG)] in patients with T2DM. Altogether, 9 studies with a total sample size of 424 patients with T2DM were included in the analysis. Combining 9 effect sizes from 9 RCTs, we found a significant lowering effect of zinc supplementation on serum levels of TG (weighted mean difference (WMD): -17.08, 95% CI: -30.59, -3.58 mg/dL, P = 0.01) and TC (WMD: -26.16, 95% CI: -49.69, -2.62 mg/dL, P = 0.02). Although the overall effect of zinc supplementation on LDL-C levels was not significant, a beneficial effect was seen in studies that administered <100 mg/d zinc. Based on the non-linear dose-response analysis, a greater reduction in serum levels of TC and LDL-C following zinc supplementation was seen at <12 weeks' duration of intervention. Unlike the overall effect size, we found a significant increasing effect of zinc supplementation on serum HDL-C concentrations in most subgroups of RCTs according to the subgroup analyses.
CONCLUSION
We found that zinc supplementation may beneficially influence lipid profile in patients with T2DM.
Topics: Adult; Aged; Biomarkers; Diabetes Mellitus, Type 2; Dietary Supplements; Dyslipidemias; Female; Gluconates; Humans; Lipids; Male; Middle Aged; Randomized Controlled Trials as Topic; Treatment Outcome; Zinc Sulfate
PubMed: 32451277
DOI: 10.1016/j.numecd.2020.03.021 -
The Cochrane Database of Systematic... Dec 2016Pneumonia is a leading cause of morbidity and mortality in children younger than five years of age. Most deaths occur during infancy and in low-income countries. Daily... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Pneumonia is a leading cause of morbidity and mortality in children younger than five years of age. Most deaths occur during infancy and in low-income countries. Daily zinc supplements have been reported to prevent acute lower respiratory tract infection (LRTI) and reduce child mortality. This is an update of a review first published in 2010.
OBJECTIVES
To evaluate the effectiveness of zinc supplementation in the prevention of pneumonia in children aged two to 59 months.
SEARCH METHODS
We searched CENTRAL (Issue 21 October 2016), MEDLINE (1966 to October 2016), Embase (1974 to October 2016), LILACS (1982 to October 2016), CINAHL (1981 to October 2016), Web of Science (1985 to October 2016) and IMSEAR (1980 to October 2016).
SELECTION CRITERIA
Randomised controlled trials (RCTs) evaluating zinc supplementation for the prevention of pneumonia in children aged from 2 months to 59 months.
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed trial quality and extracted data.
MAIN RESULTS
We did not identify any new studies for inclusion in this update. We included six studies that involved 5193 participants.Analysis showed that zinc supplementation reduced the incidence of pneumonia by 13% (fixed-effect risk ratio (RR) 0.87; 95% confidence interval (CI) 0.81 to 0.94, six studies, low-quality evidence) and prevalence of pneumonia by 41% (random-effects RR 0.59; 95% CI 0.35 to 0.99, one study, n = 609, low-quality evidence). On subgroup analysis, we found that zinc reduced the incidence of pneumonia defined by specific clinical criteria by 21% (i.e. confirmation by chest examination or chest radiograph) (fixed-effect RR 0.79; 95% CI 0.0.71 to 0.88, four studies, n = 3261), but had no effect on lower specificity pneumonia case definition (i.e. age-specific fast breathing with or without lower chest indrawing) (fixed-effect RR 0.95; 95% CI 0.86 to 1.06, four studies, n = 1932).
AUTHORS' CONCLUSIONS
Zinc supplementation in children is associated with a reduction in the incidence and prevalence of pneumonia.
Topics: Child, Preschool; Gluconates; Humans; Infant; Pneumonia; Randomized Controlled Trials as Topic; Zinc Acetate; Zinc Compounds; Zinc Sulfate
PubMed: 27915460
DOI: 10.1002/14651858.CD005978.pub3 -
The Cochrane Database of Systematic... Oct 2007Sickle cell disease is an inherited disorder of haemoglobin, which results in abnormal red blood cells. These can deform and cause blockages in blood vessels, leading to... (Review)
Review
BACKGROUND
Sickle cell disease is an inherited disorder of haemoglobin, which results in abnormal red blood cells. These can deform and cause blockages in blood vessels, leading to acute crises such as pain; stroke and splenic sequestration; and chronic organ and tissue damage. Recently research has begun to focus on therapies which prevent the red blood cells deforming by reducing the loss of water and ions from the cells. However, little is known about the effectiveness and safety of such drugs.
OBJECTIVES
To assess the relative risks and benefits of drugs which aim to prevent sickle cell-related crises by reducing red blood cell dehydration.
SEARCH STRATEGY
We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register which comprises of references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Date of the most recent search of the Group's Haemoglobinopathies Trials Register: November 2006.
SELECTION CRITERIA
Randomised or quasi-randomised controlled trials of drugs which aim to prevent sickle cell crises by reducing red cell dehydration, compared to placebo or an alternative treatment.
DATA COLLECTION AND ANALYSIS
Both authors independently selected studies for inclusion, assessed study quality and extracted data from the included studies.
MAIN RESULTS
Of the 39 studies identified, one met the inclusion criteria. This study tested the effectiveness of zinc sulphate to prevent sickle cell-related crises in a total of 145 participants and showed a significant reduction in the total number of pain, haemolytic, aplastic and sequestration crises over one and a half years, WMD -2.83 (95% CI -3.51 to -2.15). However, our analysis was limited by non-reporting of standard deviations for some data. Changes to red cell parameters and blood counts were inconsistent. No serious adverse events were noted in the study.
AUTHORS' CONCLUSIONS
While the results of zinc for reducing sickle-related crises are encouraging, larger and longer-term multicentre studies over a number of years are needed to evaluate the effectiveness of this therapy for people with sickle cell disease.
Topics: Anemia, Sickle Cell; Antisickling Agents; Dehydration; Erythrocytes; Humans; Piracetam; Randomized Controlled Trials as Topic; Zinc Sulfate
PubMed: 17943791
DOI: 10.1002/14651858.CD003426.pub2 -
The Cochrane Database of Systematic... 2002Sickle cell disease is an inherited disorder of haemoglobin, which results in abnormal red blood cells. These can deform and cause blockages in blood vessels, leading to... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Sickle cell disease is an inherited disorder of haemoglobin, which results in abnormal red blood cells. These can deform and cause blockages in blood vessels, leading to acute crises such as pain, stroke and splenic sequestration, and chronic organ and tissue damage. Recently research has begun to focus on therapies which prevent the red blood cells deforming by reducing the loss of water and ions from the cells. However, little is known about the effectiveness and safety of such drugs.
OBJECTIVES
To assess the relative risks and benefits of drugs which aim to prevent sickle cell related crises by reducing red blood cell dehydration.
SEARCH STRATEGY
We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group specialist register which comprises references identified from comprehensive electronic database searches, handsearching relevant journals and handsearching abstract books of conference proceedings. Date of the most recent search of the Group's specialised register: December 2001.
SELECTION CRITERIA
All those randomised or quasi-randomised controlled trials of drugs which aim to prevent sickle cell crises by reducing red cell dehydration, compared to placebo or an alternative treatment.
DATA COLLECTION AND ANALYSIS
Both reviewers independently selected trials for inclusion, assessed trial quality and extracted data from the included studies.
MAIN RESULTS
Of the 27 trials identified, two met the inclusion criteria. The two trials tested the effectiveness of zinc sulphate and piracetam to prevent sickle cell related crises in a total of 246 patients. A reduction in pain crises was shown in the piracetam study over one year (weighted mean difference (WMD) -1.9 (95% CI -3.01, -0.79)), although blood counts were not significantly changed. The zinc trial showed a significant reduction in the total number of pain, haemolytic, aplastic and sequestration crises over one and a half years (WMD -2.83 (95% CI -3.51, -2.15)), but our analysis was limited by non-reporting of standard deviations for some data. Changes to red cell parameters and blood counts were inconsistent. No serious adverse events were noted in either trial.
REVIEWER'S CONCLUSIONS
While the results of both zinc and piracetam for reducing sickle related crises are encouraging, larger, and/or longer term multicentre trials over a number of years are needed to evaluate the effectiveness of these therapies for patients with sickle cell disease.
Topics: Anemia, Sickle Cell; Antisickling Agents; Dehydration; Erythrocytes; Humans; Piracetam; Randomized Controlled Trials as Topic; Zinc Sulfate
PubMed: 12519597
DOI: 10.1002/14651858.CD003426