***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: The effect of Tegretol has been investigated in 71 patients with facial pain , using a single blind technique .  Tegretol was found to have an immediate good effect in 83 per cent of patients with typical trigeminal neuralgia , in 87 per cent of those with atypical neuralgia , and in 53 per cent of those with non‐neuralgiform facial pain .  Pain disappeared within the first 24 hours of treatment in 69 per cent and within the following 24 hours in a further 24 per cent . The 54 patients with a good immediate effect of Tegretol continued to take the drug after discharge , and 69 per cent of these were free of pain for over two years . Complications made withdrawal of treatment necessary in 5 per cent of the patients . One patient developed cardiac pain , three rash , three headache , nausea and vomiting , and two dizziness .  Tegretol acts by reducing the bulbar and spinal polysynaptic reflexes . It has a central action , in particular on the reticulo‐thalamic system . Our present knowledge of the mode of action of Tegretol supports the hypothesis that trigeminal neuralgia is due to pathological multineuronal reflexes in the trigeminal system on the level spinal trigeminal nuclei‐thalamus Objective The aim of this study was to evaluate whether early treatment with carbamazepine decreases the incidence of neuropathic pain ( NP ) or its intensity in patients with spinal cord injury . Design This study was a r and omized , double-blind , placebo-controlled clinical trial at a third-level university hospital involving patients older than 18 yrs with a diagnosis of spinal cord injury sustained within 2 wks before enrollment and without evidence of NP . The patients received either carbamazepine up to 600 mg/day or placebo for 1 mo . Pain intensity was measured with a 10-cm visual analog scale and the SF-36 bodily pain subscale ; quality -of-life , with the Short Form 36 ( SF-36 ) Scale ; and depression , with the Zung Self-Rating Depression Scale . Measurements were carried out at the start of the r and omized trial and at the 1- , 3- , and 6-month follow-up assessment s. Results Twenty-one of 46 patients developed NP . At the 1- , 3- , and 6-month follow-up assessment s , NP was present in 4 , 11 , and 10 patients of the carbamazepine group and in 8 , 9 , and 8 patients of the placebo group , respectively . At 1 mo , two patients in the carbamazepine group vs. eight patients in the placebo group reported moderate/intense pain ( visual analog scale , ≥4.0 ; P = 0.024 ) . At the 3- and 6-month follow-up appointments , moderate/intense pain was reported by eight vs. six ( P = 0.498 ) and six vs. eight patients ( P = 0.298 ) , carbamazepine and placebo group , respectively . There was no difference in the depression ratings or in any of the SF-36 scales . Conclusions Early intervention with carbamazepine decreased NP incidence at the 1-month but not at the 3- and 6-month follow-ups in the group of patients with acquired spinal cord injury Abstract  Variability  in patients ' response to interventions in pain and other clinical setting s is large . Many explanations such as trial methods , environment or culture have been proposed , but this paper sets out to show that the main cause of the variability may be r and om chance , and that if trials are small their estimate of magnitude of effect may be incorrect , simply because of the r and om play of chance . This is highly relevant to the questions of ‘ How large do trials have to be for statistical accuracy ? ’ and ‘ How large do trials have to be for their results to be clinical ly valid ? ’ The true underlying control event rate ( CER ) and experimental event rate ( EER ) were determined from single‐dose acute pain analgesic trials in over 5000 patients . Trial group size required to obtain statistically significant and clinical ly relevant ( 0.95 probability of number‐needed‐to‐treat within ±0.5 of its true value ) results were computed using these values . Ten thous and trials using these CER and EER values were simulated using varying group sizes to investigate the variation due to r and om chance alone . Most common analgesics have EERs in the range 0.4–0.6 and CER of about 0.19 . With such efficacy , to have a 90 % chance of obtaining a statistically significant result in the correct direction requires group sizes in the range 30–60 . For clinical relevance nearly 500 patients are required in each group . Only with an extremely effective drug ( EER>0.8 ) will we be reasonably sure of obtaining a clinical ly relevant NNT with commonly used group sizes of around 40 patients per treatment arm . The simulated trials showed substantial variation in CER and EER , with the probability of obtaining the correct values improving as group size increased . We contend that much of the variability in control and experimental event rates is due to r and om chance alone . Single small trials are unlikely to be correct . If we want to be sure of getting correct ( clinical ly relevant ) results in clinical trials we must study more patients . Credible estimates of clinical efficacy are only likely to come from large trials or from pooling multiple trials of conventional ( small ) size Carbazepine , Tegretol ( 5-carbamyl-dibenz (b , f)azepin ) , originally known as G.32883 and introduced in 1959 as an anticonvulsant , was first shown to have some effect in relieving the pain oftrigeminal neuralgia  by Blom ( 1962 , 1963 ) . Since then Spillane ( 1963 , 1964 ) , McArdle ( 1963 ) , and Taylor ( 1963 ) have confirmed that this drug has a specific effect in relieving the pain of trigeminal neuralgia in some 60 to 80 % of patients . This paper describes a controlled trial of  carbazepine  carried out simultaneously at The National Hospital , Queen Square , London , Cardiff Royal Infirmary , and Guy 's Hospital , London TIC DOULOUREUX is an often incapacitating affliction for which no completely satisfactory medical treatment has been available . While early observations that diphenylhydantoin has beneficial effects have been generally confirmed , 1 - 4 results with this drug are variable . Low doses are often ineffective , while the high dosages sometimes required for symptom control are poorly tolerated . Recently , Blom 5,6 and others 7 - 13 have reported that the paroxysmal pain of trigeminal neuralgia is promptly and consistently suppressed by the administration of carbamazepine ( Tegretol ) , an iminostilbene derivative with anticonvulsant activity . Chemically , the compound is 5 carbamyl-5H-dibenz ( b , f ) -azepine , and , as indicated by the structural formula ( Fig 1 ) , it is related to the antidepressant imipramine , but not to the hydantoins . While results with carbamazepine in typical tic douloureux are reported to be highly promising , the benefits observed in postherpetic and atypical facial neuralgias have been minimal . No controlled clinical trials with carbamazepine have been reported BACKGROUND Traditional and largely qualitative review s of evidence are now giving way to much more structured systematic overviews that use a quantitative method to calculate the overall effect of treatment . The latter approach is dependent on the quality of primary studies , which may introduce bias if they are of poor method ologic quality . OBJECTIVE To test the hypothesis that the inclusion of poor- quality trials in meta-analyses would bias the conclusions and produce incorrect estimates of treatment effect . METHODS An overview of r and omized trials of antiestrogen therapy in subfertile men with oligospermia was performed to test the hypothesis . Data sources included online search ing of MEDLINE and Science Citation Index data bases between 1966 and 1994 , scanning the bibliography of known primary studies and review articles , and contacting experts in the field . After independent , blind assessment , nine of 149 originally identified studies met the inclusion criteria and were selected . We assessed study quality independently . Outcome data from each study were pooled and statistically summarized . RESULTS There was a marginal improvement in pregnancy rate with antiestrogen treatment ( odds ratio , 1.6 ; 95 % confidence interval , 0.9 to 2.6 ) . Sensitivity analyses on the basis of method ologic quality demonstrated that poor- quality studies produced a positive effect with treatment , whereas no benefit was observed with high- quality studies . CONCLUSION The results of a meta- analysis are influenced by the quality of the primary studies included . Method ologically , poor studies tend to exaggerate the overall estimate of treatment effect and may lead to incorrect inferences & NA ; The current analysis compares changes in pain with changes in function and health status in individuals with painful diabetic peripheral neuropathy ( DPN ) . The post hoc analysis is based on a 12 week , multinational , placebo‐controlled trial of pregabalin in which 401 patients were r and omized to treatment . Study measures included the Brief Pain Inventory short‐form ( BPI‐sf ) , EQ‐5D and other patient‐reported outcomes . Cutpoints were derived on the BPI‐sf 0–10 average pain numeric rating scale [ NRS ] to classify pain grade s of “ mild ” ( 1–3 ) , moderate ( 4–6 ) and severe ( 7–10 ) , adjusting for geographical regions where data were collected . Two different metrics were used to classify the importance of change in pain severity from baseline to 12 weeks : changes in pain severity grade s ( defined by cutpoint categories ) and percent reduction in the NRS ( categories ranging from 0–9 % to ≥50 % ) . An improvement in one pain grade or a ≥30 % reduction in the NRS served as determinants of a clinical ly important difference . Patients with a one‐ grade reduction in pain severity , either from “ severe‐to‐moderate ” or “ moderate‐to‐mild , ” had a 3‐point improvement the BPI‐sf Pain Interference Index ( PII ; a composite measure of function ) ; a reduction from “ severe‐to‐mild ” pain corresponded to a 6‐point improvement in the PII . Similarly , a reduction in the NRS of ≥30 % and ≥50 % corresponded to a 3‐point and a 5‐point improvement in the PII , respectively . Changes in pain were also associated with changes in health status . Results suggest that patients whose pain is not reduced to a mild level of severity can still experience clinical ly important changes in function and health status Background : Anticonvulsants are regarded as useful for the treatment of  neuropathic pain . In this study , we evaluated the efficacy and occurrence of side effects of lamotrigine ( LTG ) in comparison with carbamazepine ( CBZ ) , in trigeminal neuralgia ( TN ) patients . Methods : The study was an interventional and crossover comparison . Twenty‐one patients with TN were administered with LTG in comparison to CBZ . The clinical trials comprised two phases of 40 days each , with an intervening three‐day washout period . The final titration in dose for LTG was 400 mg and 1,200 mg for CBZ . Efficacy of the medications involved was determined by visual analog scale ( VAS ) and verbal rating scale ( VRS ) . Side effects were recorded through marking of the profiles of side effects encountered on administration of LTG and CBZ , together with baseline haematological , hepatic and renal investigations . Results : Both on VAS and VRS assessment s , in terms of proportion of patients , CBZ benefitted 90.5 % ( 19/21 ) of the patients with pain relief ( p < 0.05 ) , in contrast to 62 % ( 13/21 ) from LTG . On VAS assessment , of the 13 patients who gained pain relief from LTG and 19 from CBZ , 77 % ( 10/13 ) obtained a “ complete ” degree of pain relief  from LTG , as compared with 21 % ( 4/19 ) from CBZ . On VRS assessment , with LTG , 84 % ( 11/13 ) of the patients accomplished “ much better ” degree of pain relief , as compared with 26 % ( 5/19 ) with CBZ . On LTG , 67 % ( 14/21 ) of patients endured general pharmacological side effects , as compared with 57 % ( 12/21 ) of patients on CBZ ( p > 0.05 ) . Meanwhile , LTG inflicted 14 % ( 3/21 ) of the patients with haematological , hepatic and renal derangements , as compared with 48 % ( 10/21 ) on CBZ . Conclusion : LTG is generally an effective and safe treatment for management of TN , compared to CBZ We analysed 113 reports published in 1980 in a sample of medical journals to relate features of study design to the magnitude of gains attributed to new therapies over old . Overall we rated 87 per cent of new therapies as improvements over st and ard therapies . The mean gain ( measured by the Mann-Whitney statistic ) was relatively constant across study design s , except for non-r and omized controlled trials with sequential assignment to therapy , which showed a significantly higher likelihood that a patient would do better on the innovation than on st and ard therapy ( p = 0.004 ) . R and omized controlled trials that did not use a double-blind design had a higher likelihood of showing a gain for the innovation than did double-blind trials ( p = 0.02 ) . Any evaluation of an innovation may include both bias and the true efficacy of the new therapy , therefore we may consider making adjustments for the average bias associated with a study design . When interpreting an evaluation of 
    Output:
    
Serious adverse events were not reported consistently ; rashes were associated with carbamazepine .
Carbamazepine is probably effective in some people with chronic neuropathic pain , but with caveats .