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What the FDA labels say about taking them together

Magnesium sulfate/potassium chloride/sodium sulfate and penicillamine

Magnesium sulfate/potassium chloride/sodium sulfate's FDA label of January 31, 2026 names penicillamine in its drug interactions section; the penicillamine labels PlainMeds reads (2) do 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 penicillamine FDA label on DailyMed (effective January 26, 2026, Bausch Health US, LLC).

What does the magnesium sulfate/potassium chloride/sodium sulfate label say about penicillamine?

Magnesium sulfate/potassium chloride/sodium sulfate label, drug interactions

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 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 penicillamine label say about magnesium sulfate/potassium chloride/sodium sulfate?

Penicillamine's label (effective January 26, 2026) and its 1 other brand-application label do 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 (Cuprimine), NDA019853 (Valeant Pharms Intl), as published by Bausch Health US, LLC, effective January 26, 2026 (SPL set 80e736d3-2017-4d68-94b4-38255c3c59c6), 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

0Magnesium sulfate/potassium chloride/sodium sulfate generic labelers
9Penicillamine generic labelers
Magnesium sulfate/potassium chloride/sodium sulfatePenicillamine
Labeled forn/aRheumatoid arthritis
Boxed warningNoYes
Pharmacy cost (NADAC)$6.74 per tablet 1.479-0.225-0.188 g tabletn/a
Shortage nowNo current entryNo 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?