What the FDA labels say about taking them together
Calcium acetate and tecovirimat
Tecovirimat's FDA label of December 31, 2025 names calcium acetate in its drug interactions section; the calcium acetate label PlainMeds reads does not name tecovirimat. The tecovirimat label: “Monitor for signs or symptoms of adverse effects when TPOXX is co-administered with phosphate binders.”
Check it at the source: the calcium acetate FDA label on DailyMed (effective July 1, 2025, Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc.); the tecovirimat FDA label on DailyMed (effective December 31, 2025, SIGA Technologies, Inc.).
What does the calcium acetate label say about tecovirimat?
Calcium acetate's label (effective July 1, 2025) does not name tecovirimat in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (calcium acetate), Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc., effective July 1, 2025 (SPL set d48c66a9-26fe-4e1a-a68a-88afe83fb51d), via openFDA; the full label on DailyMed
What does the tecovirimat label say about calcium acetate?
Tecovirimat label, drug interactionsConcomitant Drug Class/Drug Name: Calcium acetate Lanthanum carbonate Sevelamer carbonate Sucroferric oxyhydroxide; Effect on Concentration a: ↑ tecovirimat; Clinical Effect/Recommendation: Monitor for signs or symptoms of adverse effects when TPOXX is co-administered with phosphate binders [see Overdose ()].
Source: FDA drug label (TPOXX), SIGA Technologies, Inc., effective December 31, 2025 (SPL set fce826ab-4d6a-4139-a2ee-a304a913a253), 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
| Calcium acetate | Tecovirimat | |
|---|---|---|
| Labeled for | n/a | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | $0.170 per capsule 667 mg capsule | 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