What the FDA labels say about taking them together
Diltiazem and magnesium sulfate
Magnesium sulfate's FDA label (Magnesium Sulfate In Dextrose) of August 24, 2026 names diltiazem in its drug interactions section; the diltiazem labels PlainMeds reads (4) do not name magnesium sulfate.
Check it at the source: the diltiazem FDA label on DailyMed (effective August 7, 2026, Bausch Health US, LLC); the magnesium sulfate FDA label on DailyMed (effective August 24, 2026, Hospira, Inc.).
What does the diltiazem label say about magnesium sulfate?
Diltiazem's label (effective August 7, 2026) and its 3 other brand-application labels 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 (TIAZAC EXTENDED RELEASE), Bausch Health US, LLC, effective August 7, 2026 (SPL set c567fe7e-887e-4291-a0d1-2dd3f25cbf25), via openFDA; the full label on DailyMed
What does the magnesium sulfate label say about diltiazem?
Magnesium Sulfate In Dextrose label (Hospira, Inc., August 24, 2026), drug interactionsDihydropyridine Calcium Channel Blockers Clinical Impact: • An exaggerated hypotensive response is possible with the concomitant use of Magnesium Sulfate in 5% Dextrose Injection with dihydropyridine calcium channel blockers. The potential for magnesium sulfate to affect other calcium channel blockers (…) is unknown. Intervention: • Monitor vital signs (heart rate, blood pressure, respiration) frequently. • Supportive care and/or discontinuation of the calcium channel blocker may be required. Examples: • Amlodipine, clevidipine, felodipine, isradipine, nicardipine, nifedipine, nimodipine, and nisoldipine
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
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
| Diltiazem | Magnesium sulfate | |
|---|---|---|
| Labeled for | High blood pressure, Angina, Atrial fibrillation | Seizures and epilepsy, Constipation, Pain |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.144 per capsule 24h ER(cd) 120 mg capsule | $0.0039 per gram Epsom salt |
| Shortage now | A presentation being discontinued | 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