What the FDA labels say about taking them together
Camizestrant and ribociclib
Camizestrant's FDA label of September 4, 2026 names ribociclib in its boxed warning section; the ribociclib label PlainMeds reads does not name camizestrant. The camizestrant label: “… is indicated to be used in combination with CDK4/6 inhibitors, including ribociclib, which is a strong CYP3A inhibitor and can prolong the QT interval.”
Check it at the source: the camizestrant FDA label on DailyMed (effective September 4, 2026, AstraZeneca Pharmaceuticals LP); the ribociclib FDA label on DailyMed (effective July 1, 2026, Novartis Pharmaceuticals Corporation).
What does the camizestrant label say about ribociclib?
Camizestrant label, boxed warningARRHYTHMIA RISK WITH CONCOMITANT USE OF QTc INTERVAL PROLONGING DRUGS ETCAMAH in combination with ribociclib, a QTc interval prolonging drug and a strong CYP3A inhibitor, or in combination with other QTc interval prolonging drugs, can increase the risk of Torsades de Pointes, other ventricular arrhythmias, and sudden death ( 5.1 , 5.2 , 7.1 ).
Camizestrant label, drug interactionsMechanism and Clinical Effect; • Camizestrant is a CYP3A substrate. Concomitant use with strong CYP3A inhibitors increases camizestrant plasma concentrations [see Clinical Pharmacology ()], which may increase the risk of adverse reactions related to ETCAMAH. • ETCAMAH is indicated to be used in combination with CDK4/6 inhibitors, including ribociclib, which is a strong CYP3A inhibitor and can prolong the QT interval [see Warnings and Precautions () and Drug Interactions ()].
Camizestrant label, warnings and precautionsWhen ETCAMAH is used in combination with ribociclib, a CDK4/6 inhibitor that causes QTc interval prolongation and is a strong CYP3A inhibitor, there is potential for an increased risk of Torsades de Pointes, other ventricular arrhythmias, and sudden death.
Source: FDA drug label (ETCAMAH), AstraZeneca Pharmaceuticals LP, effective September 4, 2026 (SPL set c54223d3-f3c7-4186-afa0-429d84805826), via openFDA; the full label on DailyMed
What does the ribociclib label say about camizestrant?
Ribociclib's label (effective July 1, 2026) does not name camizestrant in these sections. A label lists what its studies and reports found; it is not a complete list.
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
| Camizestrant | Ribociclib | |
|---|---|---|
| Labeled for | n/a | Breast cancer |
| Boxed warning | Yes | No |
| Pharmacy cost (NADAC) | n/a | $289.72 per unit 600 mg daily dose |
| 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