Magnesium Sulfate
| Evidence Level: L1 | Predicted Indications: 10 |
Table of Contents
Magnesium Sulfate: From Constipation and Pre-eclampsia to Preeclampsia/Eclampsia
One-Sentence Summary
Magnesium sulfate is an established mineral salt, originally used as a laxative for constipation and as an anticonvulsant in pre-eclampsia. The TxGNN model predicts it for Preeclampsia/Eclampsia, but this is already an existing use rather than a true repurposing. The prediction is supported by 29 clinical trials and 20 publications compiled for this report, mostly dose-optimisation studies.
Quick Overview
| Item | Content |
|---|---|
| Original Indication | Constipation; severe, mild and unspecified pre-eclampsia (from the knowledge graph; the Singapore licence records contain no indication text) |
| Predicted New Indication | Preeclampsia/Eclampsia |
| TxGNN Prediction Score | 99.999% |
| Evidence Level | L1 |
| Singapore Market Status | ✓ Marketed |
| Number of Registrations | 2 |
| Recommended Decision | Proceed with Guardrails |
Note: The top prediction overlaps with the drug's existing indications. The more genuinely new directions are lower-ranked and are summarised at the end of the Conclusion.
Why is This Prediction Reasonable?
Currently, detailed mechanism of action data is not available in the compiled data. Based on known information, magnesium sulfate is the standard anticonvulsant for preventing and treating seizures in preeclampsia and eclampsia. Proposed mechanisms include NMDA receptor antagonism, cerebral vasodilation and calcium channel blockade.
The predicted indication matches the drug's original pre-eclampsia indication, so the evidence confirms an existing use rather than opening a new one. "Toxemia of pregnancy" (rank 2) is a synonym for the same condition and shares the same trial list, so it should not be counted as independent evidence. Current trials focus on optimising the regimen: 1 g vs 2 g/h maintenance, low-dose vs Pritchard regimens, obesity-adjusted dosing and postpartum duration.
Clinical Trial Evidence
The 10 most relevant of the 29 trials listed for this prediction:
| Trial Number | Phase | Status | Enrollment | Key Findings |
|---|---|---|---|---|
| NCT02317146 | Phase 2/3 | Completed | 280 | Postpartum magnesium sulfate for 6 vs 24 hours in severe preeclampsia after under 8 hours of pre-delivery treatment |
| NCT03164304 | Phase 4 | Completed | 222 | 1 g vs 2 g IV maintenance dose in severe pre-eclampsia |
| NCT00004399 | N/A | Completed | 2000 | Nimodipine vs magnesium sulfate for preventing eclamptic seizures |
| NCT04501289 | N/A | Completed | 114 | Low-dose regimen vs standard Pritchard regimen |
| NCT06486025 | Phase 1/2 | Unknown | 100 | Alternate dosing in overweight and obese women |
| NCT03318211 | Phase 4 | Unknown | 100 | Continuing vs stopping magnesium sulfate after delivery |
| NCT02396030 | Phase 4 | Terminated | 62 | 1 g/h vs 2 g/h maintenance for eclampsia prevention; stopped early |
| NCT02307201 | Phase 2/3 | Completed | 1114 | 24-hour vs no postpartum magnesium after at least 8 hours of pre-delivery treatment |
| NCT07220902 | Phase 3 | Not yet recruiting | 1240 | Levetiracetam vs magnesium sulfate for eclamptic seizure prevention (equivalence design) |
| NCT03412552 | N/A | Completed | 1238 | Observational analysis of intensive care management; magnesium sulfate used for convulsion control |
Literature Evidence
| PMID | Year | Type | Journal | Key Findings |
|---|---|---|---|---|
| 9794688 | 1998 | Review | Obstet Gynecol | Efficacy, benefits and risks of magnesium sulfate seizure prophylaxis |
| 2288560 | 1990 | Review | Am J Obstet Gynecol | Magnesium sulfate as the ideal anticonvulsant; efficacy and safety documented over 60 years |
| 32980358 | 2022 | Review | Am J Obstet Gynecol | Eclampsia in the 21st century; incidence and outcome disparities |
| 38669914 | 2024 | Review | Pregnancy Hypertens | Magnesium sulfate superior to other anticonvulsants for recurrent convulsions; broader indications |
| 36822712 | 2023 | Review | Obstet Gynecol Clin North Am | IV and IM regimens in high- vs low/middle-income countries |
| 10803454 | 2000 | Review | Clin Pharmacokinet | Pharmacokinetic principles of IV and IM regimens |
| 8879973 | 1996 | Review | Drug Saf | Better than diazepam or phenytoin for preventing recurrent seizures |
| 37467840 | 2023 | Review | Am J Obstet Gynecol | Questions routine use in late postpartum severe hypertension alone |
| 38872116 | 2024 | Pharmacokinetic study | BMC Pregnancy Childbirth | Population pharmacokinetics and dose optimisation in Chinese preeclampsia patients |
| 32642964 | 2020 | Pharmacokinetic study | Drugs R D | Population pharmacokinetic model and covariates |
Singapore Market Information
| Authorization Number | Product Name | Dosage Form | Approved Indication |
|---|---|---|---|
| SIN05860P | DBL Magnesium Sulfate Concentrated Injection 49.3% | Injection | Not stated in the licence record |
| SIN02748P | Lemon Sweet Purgative Syrup | Syrup | Not stated in the licence record |
Only the injection form fits the IV use required for preeclampsia/eclampsia.
Safety Considerations
- Contraindications (knowledge-graph associations, not label text): kidney disease, pyoureter, hypercalcemia, nephrocalcinosis, phosphorus metabolism disease, chronic diarrheal disease, appendicitis, atrioventricular block, hyperkalemic periodic paralysis, periodic paralysis, hypoaldosteronism, myotonia congenita, gastroparesis.
- Drug Interactions: 92 interactions recorded. Major: dolutegravir, amikacin, bictegravir. Moderate examples: nifedipine, amlodipine, doxycycline, tetracycline, ciprofloxacin, cisatracurium, corticosteroids (hydrocortisone, dexamethasone, betamethasone, triamcinolone), bisphosphonates (alendronic acid, risedronic acid, ibandronate), and vitamin D forms (cholecalciferol, calcifediol, calcitriol).
- Practical guardrails: monitor for magnesium toxicity (reflexes, respiratory rate, urine output), adjust dosing in renal impairment, and take care with calcium channel blockers and neuromuscular blockers.
Package insert warnings were not available in the data compiled for this report. Please refer to the package insert for full safety information.
Conclusion and Next Steps
Decision: Proceed with Guardrails
Rationale: Multiple completed Phase 2/3 and Phase 4 trials, plus extensive literature, support magnesium sulfate in preeclampsia/eclampsia, and an injectable product is marketed in Singapore. This is an existing use, so the work is regimen optimisation and safe use, not new-indication discovery.
To proceed, the following is needed:
- The HSA package insert warnings and contraindications (a blocking gap for safety screening)
- Mechanism of action data
- Confirmation that the injection licence covers the pre-eclampsia indication, since the licence record shows no indication text
- A renal-function and magnesium-level monitoring protocol
Other predicted indications (for reference):
- Headache disorder (rank 8): Evidence is promising, with a completed Phase 3 placebo-controlled migraine trial (NCT05967442, n=157), but results are mixed. Further confirmation is needed.
- Pharyngitis (rank 4): Evidence concerns postoperative sore throat, not infectious pharyngitis. It could be reframed as postoperative sore throat prevention.
- Thrombotic disease (rank 3): Weak, with one unreported Phase 3 TTP trial and old animal work.
- Trigeminal autonomic cephalalgia (rank 9): Limited to a small older study and case series.
- Psychotic disorder, nasal cavity disease, acute laryngopharyngitis and treatment-refractory schizophrenia: Little or no supporting evidence. Hold.
Disclaimer
This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.