What the FDA labels say about taking them together
Magnesium sulfate/potassium chloride/sodium sulfate and tetracycline
Magnesium sulfate/potassium chloride/sodium sulfate's FDA label of January 31, 2026 names tetracycline in its drug interactions section; the tetracycline label PlainMeds reads does not name magnesium sulfate/potassium chloride/sodium sulfate. The magnesium sulfate/potassium chloride/sodium sulfate label: “Administer tetracycline and fluoroquinolone antibiotics, iron, digoxin, chlorpromazine, and penicillamine at least 2 hours before and not less than 6 hours after administration of each dose of SUTAB to avoid chelation …”
Check it at the source: the magnesium sulfate/potassium chloride/sodium sulfate FDA label on DailyMed (effective January 31, 2026, Azurity Pharmaceuticals, Inc.); the tetracycline FDA label on DailyMed (effective March 18, 2025, Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc.).
What does the magnesium sulfate/potassium chloride/sodium sulfate label say about tetracycline?
Magnesium sulfate/potassium chloride/sodium sulfate label, drug interactionsAdminister tetracycline and fluoroquinolone antibiotics, iron, digoxin, chlorpromazine, and penicillamine at least 2 hours before and not less than 6 hours after administration of each dose of SUTAB to avoid chelation with magnesium.
Source: FDA drug label (SUTAB), Azurity Pharmaceuticals, Inc., effective January 31, 2026 (SPL set c020e973-dccf-4862-999e-17db6209a48a), via openFDA; the full label on DailyMed
What does the tetracycline label say about magnesium sulfate/potassium chloride/sodium sulfate?
Tetracycline's label (effective March 18, 2025) does not name magnesium sulfate/potassium chloride/sodium sulfate in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (tetracycline hydrochloride), Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc., effective March 18, 2025 (SPL set eaa5b1bd-0927-46e4-b941-32fcc492d258), 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/potassium chloride/sodium sulfate | Tetracycline | |
|---|---|---|
| Labeled for | n/a | Bacterial infections |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $6.74 per tablet 1.479-0.225-0.188 g tablet | $0.247 per capsule 250 mg capsule |
| 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