What the FDA labels say about taking them together
Magnesium sulfate and nifedipine
Magnesium sulfate's FDA label (Magnesium Sulfate In Dextrose) of August 24, 2026 names nifedipine in its drug interactions section; the nifedipine labels PlainMeds reads (2) do not name magnesium sulfate. The magnesium sulfate label: “Co-administration with unapproved tocolytics: Do not use concomitantly with beta adrenergic agents such as terbutaline and calcium channel blockers such as nifedipine”
Check it at the source: the magnesium sulfate FDA label on DailyMed (effective August 24, 2026, Hospira, Inc.); the nifedipine FDA label on DailyMed (effective December 24, 2024, Aurobindo Pharma Limited).
What does the magnesium sulfate label say about nifedipine?
Magnesium Sulfate In Dextrose label (Hospira, Inc., August 24, 2026), drug interactionsSupportive care and/or discontinuation of the calcium channel blocker may be required. Amlodipine, clevidipine, felodipine, isradipine, nicardipine, nifedipine, nimodipine, and nisoldipine.
Magnesium Sulfate In Dextrose label (Hospira, Inc., August 24, 2026), warnings and precautionsCo-administration with unapproved tocolytics: Do not use concomitantly with beta adrenergic agents such as terbutaline and calcium channel blockers such as nifedipine
Source: FDA drug label (Magnesium Sulfate In Dextrose, NDA020488), Hospira, Inc., effective August 24, 2026 (SPL set 03ebeabb-8386-4af4-3086-bdf3c3fc4a5a), via openFDA
Source: FDA drug label (Magnesium Sulfate in Water), Hospira, Inc., effective August 24, 2026 (SPL set 22ca78b4-f5a3-4144-cf89-5f633acf1e6d), via openFDA; the full label on DailyMed
What does the nifedipine label say about magnesium sulfate?
Nifedipine's label (effective December 24, 2024) and its 1 other brand-application label do not name magnesium sulfate in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (Nifedipine), Aurobindo Pharma Limited, effective December 24, 2024 (SPL set eb70b7ff-f9f0-41d0-901a-f4c04ae9ed46), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Magnesium sulfate | Nifedipine | |
|---|---|---|
| Labeled for | Seizures and epilepsy, Constipation, Pain | High blood pressure, Angina |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.0039 per gram Epsom salt | $0.130 per tablet 30 mg tablet |
| Shortage now | No current entry | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once