What the FDA labels say about taking them together
Magnesium sulfate/potassium sulfate/sodium sulfate and penicillamine
Magnesium sulfate/potassium sulfate/sodium sulfate's FDA label of June 30, 2026 names penicillamine in its drug interactions section; the penicillamine labels PlainMeds reads (2) do not name magnesium sulfate/potassium sulfate/sodium sulfate. The magnesium sulfate/potassium sulfate/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 SUPREP Bowel Prep Kit to avoid …”
Check it at the source: the magnesium sulfate/potassium sulfate/sodium sulfate FDA label on DailyMed (effective June 30, 2026, Bionpharma Inc.,); the penicillamine FDA label on DailyMed (effective January 26, 2026, Bausch Health US, LLC).
What does the magnesium sulfate/potassium sulfate/sodium sulfate label say about penicillamine?
Magnesium sulfate/potassium sulfate/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 sodium sulfate, potassium sulfate, and magnesium sulfate oral solution to avoid chelation with magnesium.
Source: FDA drug label (Suprep Bowel Prep, NDA022372), Azurity Pharmaceuticals, Inc., effective January 31, 2026 (SPL set 50f23abd-6a66-44cb-960e-d43c16a5ae5f), via openFDA
Source: FDA drug label (sodium sulfate, potassium sulfate, and magnesium sulfate), Bionpharma Inc.,, effective June 30, 2026 (SPL set 31d13799-0931-7735-e063-6294a90a6d02), via openFDA; the full label on DailyMed
What does the penicillamine label say about magnesium sulfate/potassium sulfate/sodium sulfate?
Penicillamine's label (effective January 26, 2026) and its 1 other brand-application label do not name magnesium sulfate/potassium sulfate/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
| Magnesium sulfate/potassium sulfate/sodium sulfate | Penicillamine | |
|---|---|---|
| Labeled for | n/a | Rheumatoid arthritis |
| Boxed warning | No | Yes |
| Pharmacy cost (NADAC) | $0.0901 per mL Sod sul-potass sul-mag sul solution | n/a |
| 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