***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 
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    Input: Summary Two double-blind , r and omized , placebo-controlled  multicentre studies were carried out to assess the efficacy and tolerability of subcutaneous ( s. c. ) injections of 1 - 3 mg and 1 - 8 mg sumatriptan , respectively , in the acute treatment of migraine . Data are presented from a total of 519 patients . In both studies , the primary endpoint of efficacy was a reduction in headache severity from severe or moderate to mild or no headache . All doses of sumatriptan were significantly more effective than placebo in relieving symptoms , and the response appeared to be dose-related ; an effective response to treatment was achieved within 30 min in 73 % of patients treated with 6 mg sumatriptan and 80 % of patients treated with 8 mg sumatriptan s. c. , compared with 22 % for placebo . Sumatriptan was well tolerated and the majority of adverse events were mild and transient . The most frequent complaint was irritation and pain at the site of injection . No changes in laboratory values were noted and ECG readings were unaltered by treatment . On the basis of these results , the 6 mg subcutaneous dose has been selected for further evaluation in large-scale studies BACKGROUND Sumatriptan is effective for the treatment of  acute migraine .  However , headache may recur in about 30 % of patients within 24 hours of successful treatment . OBJECTIVE To evaluate the efficacy of oral sumatriptan , 100 mg , in the treatment of headache recurring within 24 hours of achieving headache resolution with subcutaneous sumatriptan , 6 mg . STUDY DESIGN Subcutaneous sumatriptan was administered for up to 12 migraine attacks in a r and omized , double-blind , parallel-group study . Patients whose headache was completely resolved 90 minutes after subcutaneous dosing received either oral sumatriptan or placebo at the onset of recurrent headache . Patients whose headache was not completely resolved were offered rescue medication , including sumatriptan . Patients rated headache severity for 24 hours . SETTING Fifteen US outpatient clinics . MAIN OUTCOME MEASURE Percentage of patients with relief of recurrent headache and adverse events . RESULTS Approximately 90 % of patients achieved relief of headache ( severe or moderate headache reduced to mild or no headache ) by 90 minutes after unblinded subcutaneous administration of sumatriptan .  Efficacy rates were at least 80 % regardless of whether the headache fulfilled the International Headache Society criteria for migraine . About 64 % of patients achieved complete relief . Oral sumatriptan , 100 mg , relieved moderate or severe recurrent headache within 4 hours in up to 81 % of patients . Oral sumatriptan administered as rescue medication to patients not headache-free did not relieve persistent headache . The incidence , pattern , and severity of adverse events after combined subcutaneous and oral administration of sumatriptan were similar to those after subcutaneous administration alone . CONCLUSIONS Oral sumatriptan was consistently effective in the treatment of headache recurrence 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 Objective : To evaluate the efficacy and safety of sumatriptan , a 5-HTa receptor agonist , in patients with menstruationassociated migraine . Methods : Two double-blind , placebo-controlled , singleattack parallel group studies of subcutaneous sumatriptan were conducted for the acute treatment of migraine . A retrospective analysis of 1104 patients produced 157 women who were treated for a menstruation-associated migraine ( defined as a migraine beginning between 1 day before and 4 days after the onset of menstrual flow ) and 512 women treated for nonmenstrual migraine . We excluded 435 other patients who were either male ( 123 ) , women with hysterectomies ( 260 ) , or women with missing data ( 52 ) . Patients with moderate or severe pain were treated with 6 mg subcutaneous sumatriptan or placebo . One hour after treatment , response rates of headache severity and associated symptoms were measured . Menstruation-associated migraine patients were compared to female patients with nonmenstrual migraine . Migraine recurrence was analyzed retrospectively for 24 hours . Results : At 1 hour , 80 % of the sumatriptan-treated menstrual-migraine patients had pain relief ( reduction of severe or moderate pain to mild or no pain ) , compared to 19 % of the placebo patients ( P < .001 ) . Sumatriptan also treated nausea and photophobia more effectively in menstrual-migraine patients than did placebo .  Response rates for pain and associated symptoms were similar between patients with menstruation-associated and nonmenstrual migraines . Adverse effects were also similar between the groups . Conclusion : Sumatriptan was as effective and well tolerated for menstruation-associated migraine as it was for nonmenstrual migraine The results of the very first large-scale placebo-controlled dose-response trial with the novel selective 5-hydroxytryptamine1-like ( 5HT 1-like ) receptor agonist sumatriptan are presented . We studied the efficacy and tolerability of subcutaneous injections of 1 mg , 2 mg and 3 mg of sumatriptan in alleviating migraine attacks in a double-blind , placebo-controlled , parallel-group , multicentre clinical trial . Six-hundred and ninety patients were r and omized and 685 received study medication . At 30 min , reduction of headache severity to mild or none ( primary efficacy endpoint ) was achieved in 22 % ( 95 % CI : 15 - 28 % ) of placebo-treated patients and in 39 % ( CI : 31 - 46 % ) of patients treated with 1 mg sumatriptan , 44 % ( CI : 36 - 51 % ) treated with 2 mg sumatriptan and 55 % ( CI : 48 - 63 % ) treated with 3 mg sumatriptan . Differences from placebo were 17 % ( CI : 8 - 27 % ) for 1 mg sumatriptan , 22 % ( CI : 13 - 32 % ) for 2 mg sumatriptan and 34 % ( CI : 24 - 44 % ) for 3 mg sumatriptan ( p < 0.001 for all three comparisons ) . Other migraine symptoms were also more effectively treated by sumatriptan than by placebo . Subsequently , an open-label 3 mg dose subcutaneous sumatriptan was given to partial or non-responders . Thirty minutes after this open dose the response rate to sumatriptan had improved to between 70 and 80 % . Adverse events after sumatriptan were minor and short-lived . We conclude that subcutaneous sumatriptan is well tolerated in doses up to 3 + 3 mg and may rapidly abort migraine attacks This double-blind , placebo-controlled , multicenter , crossover study investigated the efficacy and tolerability of sumatriptan administered for up to three separate migraine attacks . One hundred twenty adults received sumatriptan  ( SC , 6 mg ; three attacks ) and placebo ( one attack ) . Patients completed question naires assessing the impact of migraine on their lives and the performance of sumatriptan relative to their usual acute therapies . Sumatriptan statistically outperformed placebo on all efficacy measures , including pain severity ; presence/absence of nausea , vomiting , phonophobia , and photophobia ; rescue medication use ; and clinical disability . Efficacy was consistently maintained with repeated administration . For all attacks , pain relief 90 minutes postdose occurred in 86 % to 90 % of sumatriptan-treated patients , compared with 9 % to 38 % of placebo-treated patients . Sumatriptan was well tolerated , and the frequency and severity of adverse events did not change with repeated administration . Patients ' perceptions of sumatriptan were consistent with clinical data demonstrating the drug 's high degree of efficacy and tolerability OBJECTIVE To evaluate the impact of sumatriptan succinate injection compared with placebo on productivity loss during a migraine attack in the workplace . DESIGN R and omized , double-blind , placebo-controlled , parallel-group clinical trial . SETTING Fifteen clinical centers in the United States . PATIENTS One hundred thirty-five patients 18 years and older diagnosed as having migraine according to International Headache Society criteria . INTERVENTIONS Patients self-administered sumatriptan injection ( 6 mg ) or matching placebo to treat a moderate or severe migraine occurring within the first 4 hours of a minimum 8-hour work shift . MAIN OUTCOME MEASURES Mean productivity loss 2 hours after dosing and across the work shift ; percentages of patients returning to normal work performance within 2 hours after dosing and across the work shift ; percentages of patients experiencing headache relief ( reduction of moderate or severe predose pain to mild or no pain ) 1 and 2 hours after dosing . RESULTS Mean productivity loss was significantly ( P < or = .002 ) lower in the sumatriptan group compared with the placebo group both during the 2-hour postdose period ( sumatriptan , 39 minutes ; placebo , 54 minutes ) and across the work shift ( sumatriptan , 86 minutes ; placebo , 168 minutes ) . Significantly ( P<.001 ) greater percentages of patients in the sumatriptan group compared with the placebo group returned to normal work performance by 2 hours after dosing ( sumatriptan , 52 % ; placebo , 9 % ) and across the work shift ( sumatriptan , 66 % ; placebo , 18 % ) . Significantly ( P < or = .001 ) greater percentages of patients in the sumatriptan group compared with the placebo group experienced headache relief 1 hour after dosing ( sumatriptan , 69 % ; placebo , 18 % ) and 2 hours after dosing ( sumatriptan , 79 % ; placebo , 32 % ) . CONCLUSION Sumatriptan reduced migraine-associated productivity loss during a minimum 8-hour work shift by approximately 50 % compared with placebo and alleviated headache in more than three fourths of patients We compared the efficacy and safety of subcutaneous ( SC ) sumatriptan ( 6 mg ) with that of dihydroergotamine ( DHE ) nasal spray ( 1 mg plus optional 1 mg ) in the acute treatment of  migraine . Two hundred sixty-six adult migraineurs ( International Headache Society criteria ) completed a multicenter , double-blind , double-dummy , cross-over study . Patients took SC sumatriptan for one attack and DHE nasal spray for the other in r and om order . Data from both treatment periods show that at all time points from 15 minutes , SC sumatriptan was significantly better than DHE nasal spray at providing both headache relief ( moderate/severe headache improving to mild/none ) and resolution of headache . Similarly , SC sumatriptan was superior to DHE nasal spray for the other efficacy end points assessed in the study . Patients reported that both treatments were well tolerated . Adverse events were reported by 43 % of patients taking SC sumatriptan and 22 % of patients taking DHE nasal spray . These were usually mild and transient . We conclude that subcutaneous sumatriptan has a faster onset of action than DHE nasal spray and provides greater relief of acute migraine symptoms . NEUROLOGY 1996;47 : 361 - OBJECTIVES : To investigate the efficacy of a second subcutaneous dose of 6 mg sumatriptan in the treatment of recurrence of headache after successful treatment of a migraine attack with an initial 6 mg dose . METHODS : In a prospect i ve , r and omised , placebo controlled , double blind , parallel group study ,  
    Output:
    
Relief of headache-associated symptoms , including nausea , photophobia , and phonophobia , was greater with sumatriptan than with placebo , and use of rescue medication was lower with sumatriptan than placebo .
For the most part , adverse events were transient and mild and were more common with sumatriptan than placebo .
Subcutaneous sumatriptan is effective as an abortive treatment for acute migraine attacks , quickly relieving pain , nausea , photophobia , phonophobia , and functional disability , but is associated with increased adverse events