What the FDA labels say about taking them together
Fulvestrant and ribociclib
Ribociclib's FDA label of July 1, 2026 names fulvestrant in its warnings and precautions section; the fulvestrant labels PlainMeds reads (3) do not name ribociclib. The ribociclib label: “In patients with advanced or metastatic breast cancer who received 600 mg KISQALI plus NSAI or fulvestrant, 15 out of 1054 patients (1.4%) had a > 500 ms post-baseline QTcF value and 61 out of 1054 patients (6%) had a > …”
Check it at the source: the fulvestrant FDA label on DailyMed (effective September 25, 2020, AstraZeneca Pharmaceuticals LP); the ribociclib FDA label on DailyMed (effective July 1, 2026, Novartis Pharmaceuticals Corporation).
What does the fulvestrant label say about ribociclib?
Fulvestrant's label (effective September 25, 2020) and its 2 other brand-application labels do not name ribociclib in these sections. A label lists what its studies and reports found; it is not a complete list.
Source: FDA drug label (FASLODEX), AstraZeneca Pharmaceuticals LP, effective September 25, 2020 (SPL set 83d7a440-e904-4e36-afb5-cb02b1c919f7), via openFDA; the full label on DailyMed
What does the ribociclib label say about fulvestrant?
Ribociclib label, warnings and precautionsIn patients with advanced or metastatic breast cancer (MONALEESA-2, MONALEESA-3, and MONALEESA-7) who received 600 mg KISQALI plus NSAI or fulvestrant, 15 out of 1054 patients (1.4%) had a > 500 ms post-baseline QTcF value and 61 out of 1054 patients (6%) had a > 60 ms QTcF increase from baseline.
Source: FDA drug label (KISQALI), Novartis Pharmaceuticals Corporation, effective July 1, 2026 (SPL set aaeaef94-f3f5-4367-8ea2-b181d7be2da8), 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
| Fulvestrant | Ribociclib | |
|---|---|---|
| Labeled for | Breast cancer | Breast cancer |
| Boxed warning | No | No |
| Pharmacy cost (NADAC) | n/a | $289.72 per unit 600 mg daily dose |
| Shortage now | A presentation being discontinued | 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