Table 2.
Adverse effect estimates from randomised controlled trials (Comparisons 2–4)
| Outcome or subgroup | Studies | Participants | Method (I 2 (%))* | RR (95% CI) |
|---|---|---|---|---|
|
Comparison 2: lower dose versus higher dose magnesium sulphate IM maintenance: treatment of pre-eclampsia/eclampsia | ||||
|
2.1 Death due to 'toxicity’ |
|
|
|
|
| 2.1.1 4 g IV LD; 2 g/3 h IM MD versus Pritchard’s regimen^ |
1 [28] |
126 |
F (NA) |
0.25 (0.01, 6.05) |
|
2.2 Stopped due to 'toxicity’ |
|
|
|
|
| 2.2.1 4 g IV LD; 2 g/3 h IM MD versus Pritchard’s regimen^ |
1 [28] |
126 |
F (NA) |
0.05 (0.01, 0.39) |
|
2.3 Deferred or skipped doses |
2 [27,28] |
176 |
F (0) |
0.36 (0.20, 0.63) |
| 2.3.1 4 g IV LD; 2 g/3 h IM MD versus Pritchard’s regimen^ |
1 [28] |
126 |
F (NA) |
0.43 (0.23, 0.83) |
| 2.3.2 'Dhaka’ regimen* versus 'Bhalla’ regimen~ |
1 [27] |
50 |
F (NA) |
0.23 (0.07, 0.71) |
|
2.4 Given calcium gluconate |
|
|
|
|
| 2.4.1 'Dhaka’ regimen* versus 'Bhalla’ regimen~ |
1 [27] |
50 |
F (NA) |
0.25 (0.60, 1.06) |
|
2.5 Respiratory depression |
|
|
|
|
| 2.5.1 4 g IV LD; 2 g/3 h IM MD versus Pritchard’s regimen^ |
1 [28] |
126 |
F (NA) |
0.25 (0.01, 6.05) |
|
2.6 Absent tendon reflexes |
2 [27,28] |
176 |
F (0) |
0.21 (0.10, 0.46) |
| 2.6.1 4 g IV LD; 2 g/3 h IM MD versus Pritchard’s regimen^ |
1 [28] |
126 |
F (NA) |
0.20 (0.08, 0.50) |
| 2.6.2 'Dhaka’ regimen* versus 'Bhalla’ regimen~ |
1 [27] |
50 |
F (NA) |
0.25 (0.06, 1.06) |
|
2.7 Gluteal abscess (pain, phlebitis, inflammation) |
|
|
|
|
| 2.7.1 4 g IV LD; 2 g/3 h IM MD versus Pritchard’s regimen^ |
1 [28] |
126 |
F (NA) |
No gluteal abscesses |
|
2.8 Postpartum haemorrhage |
|
|
|
|
| 2.8.1 4 g IV LD; 2 g/3 h IM MD versus Pritchard’s regimen^ |
1 [28] |
126 |
F (NA) |
0.38 (0.03, 4.03) |
|
2.9 Pulmonary oedema |
|
|
|
|
| 2.9.1 4 g IV LD; 2 g/3 h IM MD versus Pritchard’s regimen^ |
1 [28] |
126 |
F (NA) |
0.25 (0.01, 6.05) |
|
Comparison 3: magnesium sulphate IV maintenance versus IM maintenance: treatment of pre-eclampsia/eclampsia | ||||
|
3.1 Death |
|
|
|
|
| 3.1.1 4 g IV LD; 0.75 g/hour IV MD versus Pritchard’s regimen^ |
1 [29] |
137 |
F (NA) |
0.35 (0.04, 3.27) |
|
3.2 Discontinuation or modification of treatment |
2 [30,31] |
317 |
F (0) |
1.46 (0.83, 2.58) |
| 3.2.1 6 g IV LD; 2 g/hour MD versus Pritchard’s regimen^ |
1 [30] |
17 |
F (NA) |
3.33 (0.15, 71.90) |
| 3.2.2 'Springfusor pump’ IV versus 'Standard’ IM regimen |
1 [31] |
300 |
F (NA) |
1.41 (0.79, 2.52) |
|
3.3 Clinical signs of toxicity |
2 [29,30] |
154 |
R (38) |
0.82 (0.05, 12.56) |
| 3.3.1 4 g IV LD; 0.75 g/hour IV MD versus Pritchard’s regimen^ |
1 [29] |
137 |
F (NA) |
0.21 (0.01, 4.27) |
| 3.3.2 6 g IV LD; 2 g/hour MD versus Pritchard’s regimen^ |
1 [30] |
17 |
F (NA) |
3.33 (0.15, 71.90) |
|
3.4 Pain level 'acceptable’ |
|
|
|
|
| 3.4.1 'Springfusor pump’ IV versus 'Standard’ IM regimen |
1 [31] |
300 |
F (NA) |
4.93 (3.59, 6.78) |
|
3.5 Caesarean section |
2 [29,30] |
154 |
F (0) |
1.03 (0.78, 1.35) |
| 3.5.1 4 g IV LD; 0.75 g/hour IV MD versus Pritchard’s regimen^ |
1 [29] |
137 |
F (NA) |
0.99 (0.75, 1.32) |
| 3.5.2 6 g IV LD; 2 g/hour MD versus Pritchard’s regimen^ |
1 [30] |
17 |
F (NA) |
1.50 (0.47, 4.76) |
|
3.6 Postpartum haemorrhage |
|
|
|
|
| 3.6.1 4 g IV LD; 0.75 g/hour IV MD versus Pritchard’s regimen^ |
1 [29] |
137 |
F (NA) |
0.35 (0.04, 3.27) |
|
Comparison 4: short versus standard (24 hours) postpartum magnesium maintenance therapy: treatment of pre-eclampsia | ||||
|
4.1 Toxicity |
2 [32,33] |
256 |
F (NA) |
0.25 (0.06, 1.08) |
| 4.1.1 Short (12 h) versus standard (24 h) |
1 [32] |
196 |
F (NA) |
No toxicity |
| 4.1.2 Short (based on clinical criteria) versus standard (24 h) |
1 [33] |
60 |
F (NA) |
0.25 (0.06, 1.08) |
|
4.2 Side effects |
|
|
|
|
| 4.2.1 Short (based on clinical criteria) versus standard (24 h) |
1 [33] |
60 |
F (NA) |
0.17 (0.02, 1.30) |
|
4.3 'Intolerance’ |
|
|
|
|
| 4.3.1 Short (based on clinical criteria) versus standard (24 h) | 1 [33] | 196 | F (NA) | No intolerance |
^Pritchard’s regimen: 4 g IV and 10 g IM LD; 5 g IM MD/4 hours.
*Dhaka regimen: 4 g IV and 6 g IM LD; 2.5 g IM/4 hours.
~Bhalla regimen: 4 g IV and 8 g IM LD; 4 g IM/4 hours.
I2statistics is a test of heterogeneity; where I2 was > 30% summary estimates were calculated using random-effects meta-analysis; the bold effect estimates indicate statistical significance.
Abbreviations: CI confidence interval, F fixed-effect, g gram, h hour, IM intramuscular, IV intravenous, LD loading dose, MD maintenance dose, NA not applicable, R random-effects, RR risk ratio.