***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 clinical efficacy of tolfenamic acid and mefenamic acid in the treatment of primary dysmenorrhoea was studied in a prospect i ve , controlled , double-blind , cross-over study comprising 73 patients aged 13 - 39 with an average body weight of 56 kilos . The patients were r and omized to receive either tolfenamic acid ( 200 mg t.i.d . ) or mefenamic acid ( 500 mg t.i.d . ) for 3 days , during 3 consecutive menstrual cycles each , in a sequential design A-B or B-A. At the beginning and at the end of each treatment period , 13 dysmenorrhoeic symptoms were evaluated on a visual analogue scale ( lower back pain , interference with daily activities , nausea , vomiting , diarrhoea , headache , dizziness , fatigue , sweating , chills , hot flashes , depressant states , and mood swings ) . The data were analyzed by using two statistical models . The first one , for the 73 patients , by making paired comparisons regardless of treatment sequence . With respect to the initial values , the results showed that both drugs were statistically significant ( P < 0.05 ) in reducing the intensity of the evaluated symptoms . When comparing both treatments , tolfenamic acid showed a significant difference as to interference with daily activities ( P < 0.025 ) and hot flashes ( P < 0.005 ) . In the result analysis with the second model , the groups were divided according to the first assigned treatment and paired comparisons were made . It was observed that the group receiving tolfenamic acid in the last sequence reached a higher level of response and statistical significance was demonstrated in 8 of 13 evaluated symptoms . ( ABSTRACT TRUNCATED AT 250 WORDS In 12 dysmenorrheic patients we examined the therapeutic action of the Prostagl and in- synthesis inhibitor : Ibuprofen , a non-steroidal analgesic agent . Ibuprofen highly significantly reduced the resting pressure ( P less than 0.001 ) , active pressure ( P less than 0.001 ) and frequency ( P less than 0.05 ) of cyclic activity of the uterus , as well as menstrual pain ( P less than 0.001 ) . Since these effects occurred after a single oral dose of 800 mg Ibuprofen , without side effects or complications , extensive field trials are recommended with this and other PG- synthesis inhibitors , to assess their therapeutic benefits Following the demonstration that increased prostagl and in F2 alpha production causes pain similar to dysmenorrhea , and the finding that prostagl and in synthetase inhibitors are capable of relieving menstrual pain , the early theory of uterine ischemia has once again gained support as the most likely explanation for this condition . In a double-blind , placebo-controlled , crossover study , 30 of 43 women with moderate to severe dysmenorrhea who completed the trial preferred flurbiprofen ( Ansaid , Upjohn ) , a potent new analgesic/anti-inflammatory agent ( 50 mg four times daily ) , to aspirin ( 650 mg four times daily ) and placebo . Flurbiprofen was also rated superior to aspirin and placebo in the degree of pain relief . An algorithm for the diagnosis and treatment of 90 percent of women with primary dysmenorrhea is presented A multicenter open crossover study compared piroxicam and mefenamic acid and piroxicam and diclofenac in the treatment of primary dysmenorrhea in 91 patients .  Piroxicam 40 mg/day for two days followed by 20 mg/day was compared with mefenamic acid 500 mg t.i.d . and diclofenac 50 mg b.i.d . for two menstrual cycles on each drug . Assessment of efficacy found that piroxicam was more effective than either comparative drug . All three agents were well tolerated . It is concluded that piroxicam is a safe and effective drug for the treatment of primary dysmenorrhea & NA ; The paradoxical improvement of many subjective phenomena during placebo therapy is both well established and notorious for confounding many well design ed studies . Consistently high placebo response rates of as much as 44 % have been reported in subjective studies of dysmenorrhea . In an effort to evaluate the discordant role of objective uterine activity known to be associated with primary dysmenorrhea and the subjective sensation of discomfort , data from 18 patients undergoing meclofenamate therapy for primary dysmenorrhea were evaluated . In this study both the sum of pain intensity differences ( SPID ) and the total pain relief scores at each study time ( TOTPAR ) showed increases during both drug and placebo therapy with statistically significant differences favoring drug therapy . Ten percent of patients eventually reported ‘ complete relief ’ during placebo therapy . In contrast to this subjective placebo response , objective measures of intrauterine pressure showed consistent worsening in 13 out of 14 pressure parameters with 25 % of patients experiencing a 2‐fold or greater increase in the number of contractions while on placebo therapy . The ability to document unchanged or worsening objective parameters associated with the development of ‘ pain ’ in the face of reported subjective improvements may provide new insight into the mechanisms by which the ‘ placebo effect ’ occurs Forty-two women with primary dysmenorrhea were successfully enrolled in a double-blind , three-way crossover study in which each patient received either ibuprofen ( Motrin ) , indomethacin ( Indocin ) , or a placebo during each of three successive painful menstrual cycles . Thirty-one patients successfully completed the study . The results showed that ibuprofen and indomethacin were superior to the placebo in their ability to relieve pain and that patients preferred ibuprofen to indomethacin . Ibuprofen was significantly superior to the placebo regarding the number of patients who could pursue normal daily function , whereas indomethacin was not . Four patients reported side effects , all during the indomethacin cycle 90 women participated in a 4-month study . During the first 2 periods , they took no pain relievers whatsoever ; during their last 2 periods they took 2 X 325 mg aspirin , acetaminophen or an identically packaged placebo every 4 h to total 8 tablets during the first 24 h of their periods beginning with spotting . For statistical analysis , periods 1 and 2 were combined and averaged , then compared with periods 3 and 4 combined and averaged . Total menstrual loss in grams , number of days of flow , and pain of cramps and headaches were analyzed by MANOVA for each of the three treatment groups . An ANOVA for each of these variables as well as for daily menstrual loss for the first 3 menstrual days was also performed . The MANOVA for all variables by the three treatment groups failed to show any significant differences . Similarly , ANOVAs for the individual variables failed to indicate significant differences except for the variable pain of cramps ( p = 0.0072 ) . The Duncan 's Multiple Range Test for pain of cramps showed that the average pain for the placebo group was higher than for either the aspirin or the acetaminophen group , although the means for these two groups were not significantly different . These results indicate that neither aspirin nor acetaminophen in the doses given alter either total menstrual loss or the pattern of loss during the first 3 menstrual days . However , both preparations were found to be more effective than placebo in reducing pain of cramps BACKGROUND Dysmenorrhea is the most common menstrual complaint in young women , with a prevalence as high as 90 % . It is responsible for substantial repeated short-term absenteeism from school and work in young women . Effective treatments are available , including nonsteroidal anti-inflammatory drugs ( NSAIDs ) . In many countries , a variety of NSAIDs have become available as over-the-counter ( OTC ) drugs . OBJECTIVE The goal of this study was to compare the efficacy and safety of OTC doses of naproxen ( 400 mg ) and naproxen/naproxen sodium ( 200/220 mg ) with acetaminophen ( 1000 mg ) , ibuprofen ( 200 mg ) , and placebo in the treatment of primary dysmenorrhea . METHODS A pooled analysis of 5 trials was performed . Efficacy was assessed by pain relief , relief of other dysmenorrheic symptoms , time to backup medication or remedication , and treatment preference . Tolerability was assessed by recording adverse events ( AEs ) . RESULTS A total of 443 women were enrolled in the combined studies .  Naproxen 400 mg provided greater pain relief than acetaminophen and placebo within 30 minutes of administration ( P < 0.01 and P < 0.05 , respectively ) . Furthermore , naproxen 400 mg and 200 mg provided greater pain relief than both acetaminophen ( P < 0.01 and P < 0.05 , respectively ) and ibuprofen ( P < 0.001 and P < 0.01 , respectively ) at 6 hours after administration . Both doses of naproxen had higher scores than placebo for symptom relief and drug preference ( all P < 0.001 ) . The AEs and their frequency were similar among the treatment groups . No serious AEs were reported . CONCLUSION When administered at OTC doses , naproxen was effective in the relief of pain and other symptoms of primary dysmenorrhea and had a good safety profile in the population studied Abstract . The analgesic effect of paracetamol , acetyl‐salicylic acid , and placebo on  dysmenorrhea  were compared in a double‐blind cross‐over study of 30 women . There was a moderate placebo effect , but no significant difference was found between the three treatments . Blood loss was also measured and it did not vary , with the type of drug ingested . It is concluded that paracetamol and acetylsalicylic acid in the doses used ( 0.5 g x 4 for 3 days ) were not effective against heavy dysmenorrhea , and that none of the drugs influenced the amount of blood lost Summary : The efficiency and side‐effects of tiaprofenic acid , mefenamic acid and placebo were compared in the treatment of primary dysmenorrhoea . The trial was a double‐blind prospect i ve r and omized 3‐way crossover study during 6 successive menstrual cycles following a 2‐cycle run‐in period and involved 50 women with primary dysmenorrhoea selected from 96 volunteers between 16 and 35 years of age . Overall pain was significantly less ( p < 0.05 ) on treatment with tiaprofenic acid than on treatment with mefanemic acid , placebo , or the women 's usual treatments . Both active treatments were well tolerated but more side‐effects were reported during treatment with mefenamic acid Thirty‐two patients were treated with placebo tablets or indomethacin ( 25 mg three times daily ) in a six‐month , double‐blind , cross‐over trial . During indomethacin therapy , 75 per cent of patients experienced significant pain relief while associated vomiting and diarrhoea were relieved in 44 per cent and 64 per cent of patients respectively . The efficacy of indomethacin was comparable to that of other prostagl and in synthetase inhibitors Fifty-five women with primary dysmenorrhea were enrolled in a study in which each took ibuprofen ( 400 mg ) , propoxyphene hydrochloride ( 64 mg ) , or a placebo alternately in consecutive menstrual cycles for relief of pain . Fifty-one completed the study during three successive cycles in this triple-blind , crossover , r and omized investigation . Ibuprofen was clearly superior to propoxyphene and the placebo in patient preference , degree of relief , and need for supplementary analgesics . In addition , a significantly greater number of patients were able to pursue their normal daily functions during the ibuprofen cycle . Propoxyphene was superior to the placebo but not to the same extent as ibuprofen . Only three side effects were reported during the study , two relative to propoxyphene and one recorded during a placebo cycle . These data show that ibuprofen is an effective agent when used for treatment of dysmenorrhea without organic etiology Abstract . Three groups of patients with primary dysmenorrhea were treated with prostagl and in synthetase inhibitors .  Thirty‐one women received indomethacin at a dose of 25 mg × 3‐4 per day usually starting one to two days before the onset of menstruation and 38 women received naproxen 250 mg × 3–4 per day usually starting on the first day of bleeding ( open studies ) . Seventy‐one per cent of the patients experienced moderate or good relief of pain following indomethacin and 67 % following naproxen . In a third series a double‐blind crossover study using the sodium salt of naproxen versus placebo in 26 patients showed that naproxen‐sodium was significantly more effective than the placebo ( p<0.05 ) . At the doses employed , the prostagl and in synthetase inhibitors were not associated with any side effects of major concern . The study indicates that this form of therapy offers an effective alternative in patients who for some reasons do not accept hormonal treatment This communication reports the results of a double-blind , cross-over study to determine the efficacy of the prostagl and in ( PG ) synthetase inhibitor ibuprofen ( MotrinB , Upjohn ) in relieving primary dysmenorrhea , and in suppressing the release of PG in menstrual fluid . A total of 7 patients and 23 menstrual cycles were studied , following a double-blind cross-over protocol . All subjects recruited for the study were 23 - 25 years of age , nulliparous , weighed 50 - 7 
    Output:
    
When NSAIDs were compared with each other or with paracetamol , there was little evidence of the superiority of any individual NSAID with regard to either efficacy or safety .
REVIEW ER 'S CONCLUSIONS NSAIDs are an effective treatment for dysmenorrhoea , though women using them need to be aware of the significant risk of adverse effects .
There is insufficient evidence to determine which ( if any ) individual NSAID is the most safe and effective for the treatment of dysmenorrhoea