What the FDA labels say about taking them together
Belumosudil and caffeine
Belumosudil's FDA label of April 7, 2026 names caffeine in its drug interactions section; the caffeine labels PlainMeds reads (2) do not name belumosudil. The belumosudil label: “Concomitant use of REZUROCK with sensitive CYP1A2 substrates (e.g., caffeine) is predicted to increase CYP1A2 substrate exposure, which may increase the risk of adverse reactions related to these substrates.”
Check it at the source: the belumosudil FDA label on DailyMed (effective April 7, 2026, Kadmon Pharmaceuticals, LLC); the caffeine FDA label on DailyMed (effective July 29, 2026, Sagent Pharmaceuticals).
What does the belumosudil label say about caffeine?
Belumosudil label, drug interactionsConcomitant use of REZUROCK with sensitive CYP1A2 substrates (e.g., caffeine) is predicted to increase CYP1A2 substrate exposure [see Clinical Pharmacology (12.3) ], which may increase the risk of adverse reactions related to these substrates.
Source: FDA drug label (Rezurock), Kadmon Pharmaceuticals, LLC, effective April 7, 2026 (SPL set 102e4ef4-7f84-4e34-8df1-479c24d1575d), via openFDA; the full label on DailyMed
What does the caffeine label say about belumosudil?
Caffeine's label (effective July 29, 2026) and its 1 other brand-application label do not name belumosudil in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (caffeine citrate), Sagent Pharmaceuticals, effective July 29, 2026 (SPL set 5f38c395-0093-4afd-89ec-f96e5dc0934a), 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
| Belumosudil | Caffeine | |
|---|---|---|
| Labeled for | n/a | n/a |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | n/a | $0.083 per tablet 200 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