What the FDA labels say about taking them together
Metformin and trospium
Trospium's FDA label of December 30, 2025 names metformin in its drug interactions section; the metformin labels PlainMeds reads (3) do not name trospium. The trospium label: “Concomitant use with metformin immediate release tablets reduced exposure and peak concentration of trospium.”
Check it at the source: the metformin FDA label on DailyMed (effective September 3, 2026, Granules India Ltd); the trospium FDA label on DailyMed (effective December 30, 2025, Glenmark Pharmaceuticals Inc., USA).
What does the metformin label say about trospium?
Metformin's label (effective September 3, 2026) and its 2 other brand-application labels do not name trospium in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (METFORMIN HYDROCHLORIDE), Granules India Ltd, effective September 3, 2026 (SPL set 73197cb5-3e23-4ac0-b189-f9bc848bce66), via openFDA; the full label on DailyMed
What does the trospium label say about metformin?
Trospium label, drug interactionsConcomitant use with metformin immediate release tablets reduced exposure and peak concentration of trospium.
Source: FDA drug label (Trospium Chloride), Glenmark Pharmaceuticals Inc., USA, effective December 30, 2025 (SPL set d5c837a4-d1c6-4615-b7ad-27f3162a03aa), 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
| Metformin | Trospium | |
|---|---|---|
| Labeled for | Type 2 diabetes | Overactive bladder |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | $0.0145 per tablet 500 mg tablet | $0.211 per tablet 20 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