***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 The dihydroketo and dihydromonohydroxy analogues of carbamazepine ( GP 47680 and GP 47779 ) were tested against carbamazepine for efficacy and tolerability in 13 patients ( 6 male and 7 female , mean age 69 years ) and 11 patients ( 5 male and 6 female , mean age 64 years ) , respectively , all of whom were suffering from trigeminal neuralgia . Both derivatives brought about freedom from symptoms or a marked reduction in the pain in all patients . Onset of effect was observed within 48 h in most cases . For both analogues the effective dose was between 10 and 20 mg/kg body weight in most patients . There was a linear relationship , with a correlation coefficient of 0.83 ( n = 36 ; p less than 0.001 ) , between the doses and the serum level . Doses almost twice as high as those of carbamazepine are needed in order to achieve freedom from symptoms with the carbamazepine analogues . Since unwanted effects , in the form of dizziness and ataxia , occur much less frequently than with carbamazepine , the analogues can be administered in higher doses 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 A double‐blind crossover study of the effects of baclofen was conducted on 10 patients with typical trigeminal neuralgia .  Baclofen significantly decreased the number of painful paroxysms in 7 of the 10 patients . An open trial in another 50 patients with trigeminal neuralgia refractory to or unable to tolerate carbamazepine  showed that 37 ( 74 % ) were relieved of their attacks by baclofen , either alone ( 12 patients ) or in combination with previously ineffective doses of carbamazepine or phenytoin ( 25 ) . On long‐term follow‐up of one to five years ( mean , 3.0 years ) , 18 of the 60 patients ( 30 % ) continued pain free while receiving baclofen ; 10 ( 17 % ) went into remission after 3 to 6 months ; 13 ( 22 % ) became refractory to baclofen after 1 to 18 months ; and 2 ( 3 % ) elected operation despite a good response to baclofen . The results indicate that baclofen is a useful drug in the treatment of trigeminal neuralgia L-Baclofen was compared with racemic baclofen ( Lioresal ) in a double-blind crossover trial in 15 patients with typical trigeminal neuralgia .  L-Baclofen was more effective than five times as much racemic baclofen in nine patients . Six of these nine patients have continued pain-free on L-baclofen for 4 to 17 months ( mean , 10 months ) . L-Baclofen was much better tolerated than racemic baclofen . Our results suggest that L-baclofen represents a significant improvement over racemic baclofen in the treatment of trigeminal neuralgia , and support our laboratory obsemations indicating that D-baclofen  antagonizes the action of L-baclofen Baclofen ( beta-4-chlorophenyl-gamma-aminobutyric acid ) shows analgesic properties in rats and resembles carbamazepine and phenytoin in its effects on the spinal trigeminal nucleus of cats . We have , therefore , conducted a clinical trial in 25 subjects , 16 suffering from trigeminal neuralgia , and 9 patients were affected by different painful conditions such as postherpetic neuralgia , tabes dorsalis , postarachnoid radiculitis . 5 of the former groups were refractory to or unable to tolerate carbamazepine . Baclofen has significantly exhibited analgesic efficacy : all groups , as a whole , were improved by 68.61 % . These results substantiate that baclofen is useful in the treatment of trigeminal neuralgia and other painful conditions The overall crude incidence rate of trigeminal neuralgia per 100,000 population in Rochester , Minnesota , for 1945 through 1984 was 4.3 for both sexes combined . The age‐adjusted ( to total 1980 US population ) rate for women ( 5.9 ) was significantly higher than that for men ( 3.4 ) . Annual incidence rates increased significantly with age in both women and men . Data based on evidence in the medical records suggest that trigeminal neuralgia is a rather rare and unpredictable disease : The number of episodes varies from 1 to 11 , and length of episode from 1 day to 4 years . This study indicates an elevated relative risk associated with hypertension ( both overall and among women in the cohort ) . Also , prevalence of multiple sclerosis was significantly greater among the group of 75 patients who had trigeminal neuralgia . Since the data on treatment in this study do not correspond to a r and omized clinical trial , they are presented as empirical results only and show no single treatment of choice for trigeminal neuralgia Background : NMDA glutamate receptor antagonists such as ketamine and dextromethorphan reduce pain in certain neuropathic pain conditions . However , there have been no controlled trials of NMDA antagonists in facial neuralgias . Methods : A r and omized , double-blind , crossover trial compared 6 weeks of oral dextromethorphan with active placebo ( low-dose lorazepam ) in 19 patients , stratified into three groups : 11 with facial pain and possible trigeminal neuropathy , five with anesthesia dolorosa , and three with idiopathic trigeminal neuralgia . Dosage was titrated in each patient to the highest level reached without disrupting normal activities . Results : Patients completing the trial included 10 with possible trigeminal neuropathy , four with anesthesia dolorosa , and two with trigeminal neuralgia . In patients with possible trigeminal neuropathy and anesthesia dolorosa , dextromethorphan  decreased pain by a mean of only 2 to 4 % , and these estimates were not significant . Both patients with trigeminal neuralgia had more pain during dextromethorphan treatment than during placebo treatment . Of three patients who demonstrated an analgesic response to dextromethorphan during the main trial , only one repeatedly responded in four subsequent confirmatory drug – placebo crossovers . Conclusions : Dextromethorphan shows little or no analgesic efficacy in pain due to possible trigeminal neuropathy and anesthesia dolorosa . Additional trials are necessary to conclusively evaluate the efficacy of NMDA-receptor antagonists in trigeminal neuralgia Neuropathic pain may be a major cause of pain in the head and neck . Trigeminal neuralgia may appear as intraoral pain . This article review s a series of 24 consecutive cases of oral pain treated with topical capsaicin .  Complete remission of neuropathic pain was seen in 31.6 % of patients ;  partial remission was achieved in 31.6 % of patients . Trigeminal neuralgia with an intraoral trigger was less responsive to topical therapy than neuropathic pain . Further study is needed to clarify the efficacy of topical capsaicin in neuropathic and neuralgic pain and the effect of differing dosages and frequency of application . On the basis of the findings in this open-label clinical trial , controlled clinical study of capsaicin in neuropathic oral pain states appears warranted We conducted a pilot study to evaluate the efficacy of topiramate in trigeminal neuralgia using a r and omized , double-blind , placebo-controlled , two-period crossover design . Three patients were enrolled in and completed the study . All three patients responded to topiramate in this main study and entered a subsequent confirmatory study consisting of three topiramate-placebo crossovers . In the main study , topiramate  reduced pain by 31 % , 42 % , and 64 % in the three patients ( p = 0.04 ) . However , topiramate showed no effect in the confirmatory study . Given that trials of less common pain conditions are fraught with low patient recruitment rates , a multiple crossover design provides more information , which is important in conditions associated with considerable pain fluctuation . Larger trials are needed to more precisely estimate the effect of topiramate in trigeminal neuralgia & NA ; Lamotrigine is a chemically novel antiepileptic drug which has not been adequately assessed for its antineuralgic properties . It was used in a double‐blind placebo controlled crossover trial in 14 patients with refractory trigeminal neuralgia . Patients continued to take a steady dose of carbamazepine or phenytoin throughout the trial over a 31‐day period . Each arm of the trial lasted 2 weeks with an intervening 3‐day washout period . The maintenance dose of lamotrigine was 400 mg . Lamotrigine was superior to placebo ( P=0.011 ) based on analysis of a composite efficacy index which compared the numbers of patients assigned greater efficacy on lamotrigine with those assigned greater efficacy on placebo . Efficacy for one treatment over another was determined according to a hierarchy of : ( i ) use of escape medication ; ( ii ) total pain scores ; or ( iii ) global evaluations . Eleven of the 13 patients eligible for inclusion in the composite efficacy index showed better efficacy on lamotrigine compared with placebo . Global evaluations further suggested that patients did better on lamotrigine than placebo ( P=0.025 ) . The adverse reactions with both lamotrigine and placebo were predominantly dose‐dependent effects on the central nervous system . A 14th patient withdrew from the study due to severe pain during the placebo arm of the trial . It would appear that lamotrigine has antineuralgic properties CARBAMAZEPINE ( Tegretol ) has been used for more than eight years in other countries for the treatment of epilepsy and , more recently , trigeminal neuralgia . The earliest reports on its effect in trigeminal neuralgia were by Blom 1,2 in Sweden , Bonduelle et al 3 in France , and Spillane 4 and Taylor 5 in Engl and . Since then , there have been a number of additional papers . 6 - 9 The authors are in agreement on the effectiveness of this drug in trigeminal neuralgia , but the type and number of side effects have been quite variable . There have been occasional reports of serious hematopoietic effects , 10,11 but no repeated blood studies over long periods have been reported . The present study was undertaken to evaluate the side effects and also the application of this drug in some of the other neuralgias such as postherpetic , tabetic , and atypical facial neuralgia .  A double-blind technique was necessary . Carbamazepine is Baclofen is a new antineuralgic drug . A clinical trial with treatment by this drug on 20 patients of trigeminal neuralgia was done . The action of this drug is similar to that of carbamazepine , however the former gives less undesirable side-effects . Out of 20 patients under treatment by this drug , 45 % were relieved completely from pain while in 20 % intensity and /or number of attacks of pain was reduced to half and in 35 % effectiveness of Baclofen could not be observed To evaluate the reported benefit of ipsilateral single-application ophthalmic anesthetic eyedrops in patients with typical trigeminal neuralgia , a r and omized double-blind placebo-controlled trial was performed . Forty-seven patients were r and omly assigned to receive two drops of either proparacaine ( 25 cases ) or saline placebo ( 22 cases ) . The experimental and placebo groups were equivalent in regard to patient age , distribution of trigeminal neuralgia pain , duration of pain , current medication regimens , and number of prior procedures performed . Pain response was assessed at 3 , 10 , and 30 days after instillation using two pain rating scales and a measure of pain frequency . Treatment failure was defined in advance as any of the following : a lack of clinical response , the need for an increase 
    Output:
    
RESULTS Metanalisys results suggest that carbamazepine is more efficient than placebo .
CONCLUSIONS Carbamazepine is still the drug of choice for treating trigeminal neuralgia , being lamotrigine and pimozide indicated for cases refractory to conventional therapy .