***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: PURPOSE Following parenteral magnesium tocolysis for patients in preterm labor . The choice of oral tocolytic medications is controversial . METHODS Over a six-month period , 47 patients who were inpreterm labor were r and omized after parenteral magnesium tocolysis  to receive magnesium gluconate ( [ Mg-g ] 648 mg elemental magnesium/day ) or magnesium chloride ( [ Mg-c ] 640 mg elemental magnesium/ day ) . A serum magnesium was obtained 24 hours after the initiation of oral therapy . RESULTS In the 25 patients were treated with Mg-g and 22 with Mg-c there were no differences in patient demographics , initial cervical dilatation hours on parenteral magnesium sulfate , recurrent contractions , or side effects between the two groups . The cost was also similar ( Mg-c , $ 1.40/d ; Mg-g , $ 2.11/d ) . The serum magnesium levels were higher in the Mg-c group ( 1.80 + /- 0.28 mg/dl ) compared to the Mg-g group ( 1.63 + /- 0.30 mg/dl ) but the difference was not significant . CONCLUSION These two preparations of magnesium are similar in their effects on uterine activity and serum levels when used at these dosages OBJECTIVE to establish the efficacy and safety of nifedipine and magnesium sulfate in arresting preterm labor . METHOD seventy-four patients with singleton pregnancies at 23 - 36 weeks in preterm labor , were selected r and omly to receive either oral nifedipine or intravenous magnesium sulfate . RESULTS both drugs had similar tocolytic efficacy and side effects while nifedipine was faster than magnesium sulfate in arresting uterine contractions ( 4.8 + /- 4.23 vs. 2.98 + /- 3.03 h ) P = 0.04 . CONCLUSION this data suggests that oral nifedipine with the same efficacy , side effects and faster action could be a suitable and more convenient alternative to intravenous magnesium sulfate in arresting preterm labor OBJECTIVE Our purpose was to evaluate the relative efficacy and safety of indomethacin versus magnesium sulfate in the management of  preterm labor in pregnancies < 32 weeks of gestation . STUDY DESIGN Eligible patients admitted with singleton pregnancies and idiopathic preterm labor between August 1988 and October 1989 were r and omized by sealed envelopes to receive either indomethacin or intravenous magnesium sulfate . RESULTS Of 101 eligible patients 49 were r and omized to receive indomethacin .  The two study groups were similar in regard to a number of entry variables , including gestational age , cervical examination , and contraction frequency .  Indomethacin was as effective as magnesium sulfate in delaying delivery > 48 hours , 90 % versus 85 % , and together with oral terbutaline in extending the gestation , 22.9 versus 22.7 days . Tocolysis with magnesium sulfate was discontinued in eight ( 15 % ) patients because of maternal side effects , in contrast to none in the indomethacin group , p < 0.05 . CONCLUSION For gestations < 32 weeks indomethacin may be considered an appropriate alternative to magnesium sulfate as a first-time tocolytic agent OBJECTIVE This study was undertaken to compare a high-dose protocol for magnesium sulfate tocolytic therapy with a low-dose regimen with respect to time needed to achieve tocolysis . STUDY DESIGN Patients between 24 and 34 weeks ' gestation with preterm labor were included . Patients with ruptured membranes or nonreassuring fetal assessment s were excluded . Gravid women received a 4-g loading dose of magnesium sulfate and were prospect ively r and omly assigned to receive a maintenance dose of 2 or 5 g/h . RESULTS The median times to tocolysis were 120 minutes ( semi-interquartile range , 30 minutes ) in the low-dose group and 90 minutes ( semi-interquartile range , 28 minutes ) in the high-dose group ( P < .001 ) . CONCLUSION Patients treated with a higher maintenance dose of magnesium sulfate had a higher frequency of side effects ; however , tocolysis was achieved more rapidly and they required shorter admissions to the labor and delivery unit without increased maternal or neonatal morbidity An open-label , r and omised , parallel-group , study was conducted in three study centres in women with premature labor and indication for a single agent intravenous tocolysis therapy with magnesium sulphate .  The aim of this study was to examine the local and general tolerability and side-effects of magnesium sulphate for tocolysis . Furthermore , we tested the tolerability of a ready-for-use magnesium solution . No measurements of efficacy were performed during this study . Initially , patients received a loading dose of 4.0 g magnesium sulphate administered over 30 min . Thereafter , a continuous intravenous infusion of 1 - 2 g magnesium sulphate per hour up to 21 days was given . Venous score ( Maddox ) , vital signs , adverse events as well as general tolerability ( assessed by investigator and patients ) and blood parameters were assessed . We showed good local and systemic tolerability of high dose magnesium sulphate for tocolysis . Only seven patients ( 15 % ) were withdrawn from the study prematurely due to minor adverse events . Potential serious complications of MgSO(4 ) such as respiratory arrest or clinical ly relevant respiratory depression were not observed . The most frequently reported local adverse events were injection site pain , itching , erythema , swelling , in duration and palpable venous cord . The most common systemic adverse events considered to be possibly related to the study drugs involved the nervous system ( dizziness ) followed by the digestive system ( nausea , constipation ) . Systolic and diastolic blood pressure changed only slightly during the treatment . Respiratory rate and body temperature remained stable also . Toxic magnesium levels ( > 2.5 mmol/l ) were not observed . The assessment of the clinical investigators with regard to tolerability was very good or good in 72.5 % of the patients . The introduction of the ready-to-use solution has the advantage of eliminating the need to mix the solution prior to administration . This means a lower risk of overdose and contamination OBJECTIVE : To compare oral rofecoxib with intravenous magnesium sulfate as a tocolytic . METHODS : This was a r and omized study of patients who were between 22 and 34 weeks of gestation with preterm labor . Patients were r and omly assigned to receive either daily oral rofecoxib ( 50 mg ) or intravenous magnesium sulfate for a maximum of 48 hours . Outcome variables included delay of delivery for 48 hours and the incidence of side effects . Data were analyzed by using the Student t test , Mann – Whitney U test , & khgr;2 test , and repeated- measures analysis of variance . Sample size calculations were based on previous studies of tocolytic efficacy . RESULTS : Two hundred fourteen patients were r and omly assigned ( 105 received rofecoxib and 109 received magnesium sulfate ) . Delivery was delayed for 48 hours in 95 ( 90.4 % ) and 96 ( 88 % ) of the patients in the rofecoxib and magnesium sulfate groups , respectively ( relative risk 0.97 ; 95 % confidence interval 0.89 , 1.06 ) . To show a statistically significant benefit in delay of delivery past 48 hours , a total of 2,686 patients would be required in each group . There was no difference between the groups over the course of the study in cervical dilatation , amniotic fluid index , or cervical length by vaginal ultrasonography . The median hospital days on the original admission were also similar at 2 for both groups ( P = .10 ) . There was a higher reported incidence of maternal side effects in the magnesium sulfate group ( relative risk 1.81 ; 95 % confidence interval 1.07 , 3.06 ) . There was no difference in the incidence of neonatal side effects . CONCLUSION : There was no difference between oral rofecoxib and intravenous magnesium sulfate in arresting preterm labor . LEVEL OF EVIDENCE : OBJECTIVE The purpose of this study was to determine whether intravenous magnesium sulfate ( MgSO4 ) followed by oral nifidepine tocolysis in women with preterm labor between 32 0/7 and 34 6/7 weeks ' gestation reduces neonatal hospital stay . STUDY DESIGN Fifty-four women between 32 0/7 and 34 6/7 weeks with preterm labor were r and omized to receive either MgSO4 and oral nifidepine ( n = 24 ) or no tocolysis ( n = 30 ) . All women received betamethasone and prophylactic antibiotics . The primary outcome was total neonatal hospital stay . Data were analyzed using Chi-square and Mann Whitney U test . RESULTS The 2 groups had similar mean cervical dilation and gestational age  at enrollment . There were no statistically significant differences in total neonatal hospital stay ( 5.8 + /- 7.2 days ; median of 3 days in the no tocolysis vs. 7.5 + /- 8.6 days ; median of 3 days in the tocolysis group ) , rate of preterm delivery ( 57 % vs. 75 % ) or need for oxygen supplementation ( 7 % vs. 21 % , p < 0.23 ) . The neonatal complications were similar in each group . CONCLUSION Tocolysis after 32 weeks gestation does not reduce neonatal hospital stay AIM The effectiveness of the management of preterm birth remains an important health care issue , especially when considering that more than two thirds of singleton neonatal death occurs in preterm labor . The purpose of this study was to compare oral celecoxib with intravenous magnesium sulfate as tocolytic . METHODS This was a r and omized study of patients who were between 24 and 34 weeks of gestation with preterm labor . One hundred and four pregnant women with preterm labor were r and omly assigned to receive celecoxib 100 mg b.i.d . for 48 h or intravenous magnesium sulfate ( MgSO4 ) for maximum of 48 h. Outcome variables included delay of delivery for 48 h and the incidence of side-effects . Data was analyzed using the Student t-test and the chi(2 ) test . RESULTS There was no difference between the groups over the course of the study in demographic characteristics , cervical examination and amniotic fluid index . Labor was arrested for 48 h was in 42 ( 81 % ) and 45 ( 87 % ) of the patients in the celecoxib and magnesium sulfate groups , respectively ( p-0.298 ) . There were no severe maternal or neonatal complications in either group . CONCLUSION Celecoxib is as effective as magnesium sulfate for primary tocolysis OBJECTIVE The aim of this study was to compare the efficacy and safety of oral nicardipine in acute therapy for preterm labor with those of parenteral magnesium sulfate . STUDY DESIGN Patients between 24 and 34 weeks ' gestation with documented preterm labor were r and omly assigned to receive oral nicardipine ( n = 57 ) or intravenous magnesium sulfate ( n = 65 ) as initial tocolytic therapy . Patients in the nicardipine group received a 40-mg loading dose and then 20 mg every 2 hours as needed to stop contractions ( total 80 mg ) . Patients in the magnesium sulfate group received a 6-g bolus followed by 2 to 4 g/h to provide uterine quiescence . Patients could be switched to another tocolytic regimen if they continued to have contractions after 6 hours of therapy . The main outcome variables examined were time to uterine quiescence , time gained in utero , recurrence of preterm labor , failure of tocolysis , and pertinent maternal and neonatal outcomes . RESULTS There were no significant differences in maternal demographic characteristics between the groups . Among patients who responded with uterine quiescence within 6 hours , there was a significant decrease in the time to uterine quiescence in the nicardipine group ( P < .01 ) . Patients in the magnesium sulfate group were more likely to have recurrence of preterm labor necessitating further tocolytic attempts ( P = .048 ) . The patients in the magnesium sulfate group had more adverse side effects , mainly nausea and vomiting ( P = .004 ) . There were no differences in birth weight , estimated gestational age at delivery , or neonatal complications between the 2 groups . CONCLUSIONS Oral nicardipine is an effective , safe , and well-tolerated tocolytic agent . In this prospect i ve clinical trial patients r and omly assigned to receive oral nicardipine had arrest of preterm labor more rapidly than did those r and omly assigned to receive parenteral magnesium sulfate . Patients who received magnesium sulfate were more likely to have adverse medication effects and recurrent preterm labor In travenous magnesium sulfate and alcohol were compared as treatments for  premature labor .  A successful treatment was the absence of contractions for a 24 hour interval . Early treatment was found to be essential for successful management of prem 
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There is no evidence examining duration of therapy , timing of therapy and the role for repeat dosing .
However , given that evidence has been drawn from a single study ( with a small sample size ) , these data should be interpreted with caution .Magnesium sulphate has been shown to be of benefit in a wide range of obstetric setting s , although it has not been recommended for tocolysis .