Cochrane Db Syst Rev
-
There are at least two theoretical reasons to believe antidepressants might help in smoking cessation. Nicotine withdrawal may produce depressive symptoms or precipitate a major depressive episode and antidepressants may relieve these. Nicotine may have antidepressant effects that maintain smoking, and antidepressants may substitute for this effect. Alternatively, some antidepressants may have a specific effect on neural pathways underlying nicotine addiction, independent of their antidepressant effects. ⋯ The antidepressants bupropion and nortriptyline aid long term smoking cessation but selective serotonin reuptake inhibitors (e.g. fluoxetine) do not. The fact that only some forms of antidepressants aid cessation and that they do so regardless of depressive symptoms strongly suggests that their mode of action is independent of their antidepressant effect.
-
Cochrane Db Syst Rev · Oct 2004
Review Meta AnalysisProphylactic intravenous preloading for regional analgesia in labour.
Reduced uterine blood flow from maternal hypotension may contribute to fetal heart rate changes which are common following regional analgesia (epidural or spinal or combined spinal-epidural (CSE)) during labour. Intravenous fluid preloading may help to reduce maternal hypotension but using lower doses of local anaesthetic, and opioid only blocks, may reduce the need for preloading. ⋯ Preloading prior to traditional high-dose local anaesthetic blocks may have some beneficial fetal and maternal effects in healthy women. Low-dose epidural and CSE analgesia techniques may reduce the need for preloading. The studies reviewed were too small to show whether preloading is beneficial for women having regional analgesia during labour using the lower-dose local anaesthetics or opioids. Further investigation of low-dose epidural or CSE (including opioid only) blocks, and the risks and benefits of intravenous preloading for women with pregnancy complications, is required.
-
Cochrane Db Syst Rev · Oct 2004
Review Meta AnalysisNumber of embryos for transfer following in-vitro fertilisation or intra-cytoplasmic sperm injection.
The traditional reliance on the transfer of multiple embryos during in vitro fertilisation (IVF) in order to maximise the chance of pregnancy, has resulted in increasing rates of multiple pregnancies. Women undergoing IVF had a 20 - fold increased risk of twins and 400 - fold increased risk of higher order pregnancies (Martin 1998). The maternal and perinatal morbidity and mortality as well as national health service costs associated with multiple pregnancies is significantly high in comparison with singleton births (Luke 1992; Callahan 1994; Goldfarb 1996). Single embryo transfer is now being considered as an effective means of reducing this iatrogenic complication. This systematic review evaluates the effectiveness of elective two embryo transfer in comparison with single and more than two embryo transfer following IVF and ICSI (intra cytoplasmic sperm injection) treatment. ⋯ The results of this systematic review suggest that live birth and pregnancy rates following single embryo transfer are lower than those following double embryo transfer as are the chances of multiple pregnancy including twins. As such, it is unlikely that the conclusions are robust enough to catalyse a change in clinical practice. The studies included are limited by their small sample size, so that even large differences might be hidden. Cumulative livebirth rates are seldom reported. The data were inadequate to draw conclusions about single embryo transfer and first frozen single embryo transfer (1FZET) or subsequent single frozen embryo transfers. Until more evidence is available single embryo transfer may not be the preferred choice for all patients undergoing IVF/ICSI. Clinicians may need to individualise protocols for couples based on their risks of multiple pregnancy. A definitive pragmatic, large multi centre randomised controlled trial comparing single embryo versus double embryo transfer in terms of clinical and cost effectiveness as well as acceptability is required. The primary outcome measured should be cumulative livebirth per woman/couple.
-
Cochrane Db Syst Rev · Oct 2004
Review Meta AnalysisShort acting insulin analogues versus regular human insulin in patients with diabetes mellitus.
In short acting insulin analogues the dissociation of hexamers is facilitated, achieving peak plasma concentrations about twice as high and within approximately half the time compared to regular human insulin. According to these properties this profile resembles the shape of non-diabetic patients more than that of regular human insulins. Despite this theoretical superiority of short acting insulin analogues over regular human insulin, the risk-benefit ratio of short acting insulin analogues in the treatment of diabetic patients is still unclear. ⋯ Our analysis suggests only a minor benefit of short acting insulin analogues in the majority of diabetic patients treated with insulin. Until long term efficacy and safety data are available we suggest a cautious response to the vigorous promotion of insulin analogues. Due to fears of potentially carcinogenic and proliferative effects, most studies to date have excluded patients with advanced diabetic complications. For safety purposes, we need a long-term follow-up of large numbers of patients who use short acting insulin analogues. Furthermore, we need well designed studies in pregnant women to determine the safety profile for both the mother and the unborn child.
-
Cochrane Db Syst Rev · Oct 2004
Review Meta AnalysisOral oestrogen and combined oestrogen/progestogen therapy versus placebo for hot flushes.
Hot flushes and night sweats are common symptoms experienced by menopausal women. Hormone therapy (HT), containing oestrogens alone or oestrogens together with progestogens in a cyclic or continuous regimen, is often recommended for their alleviation. ⋯ Oral HT is highly effective in alleviating hot flushes and night sweats. Therapies purported to reduce such symptoms must be assessed in blinded trials against a placebo or a validated therapy because of the large placebo effect seen in well conducted randomised controlled trials, and also because during menopause symptoms may fluctuate and after menopause symptoms often decline. Withdrawals due to side-effects were only marginally increased in the HT groups despite the inability to tailor HT in these fixed dose trials. Comparisons of hormonal doses, product types or regimens require analysis of trials with these specific "within study" comparisons.