What's the safe limit for lurbinectedin daily use?

There isn’t a daily “safe limit” for lurbinectedin. It isn’t given every day. It is dosed as an IV infusion on Day 1 of a 21-day cycle (about once every 3 weeks).

Typical approved regimen (high level):
- Dose: about 2.0 mg/m^2 per cycle
- Route/time: IV infusion over about 1 hour
- Schedule: every 21 days, continued until disease progression or intolerable toxicity
- Dose adjustments: if there are significant toxicities (e.g., low blood counts, liver enzyme elevations), the next cycle can be delayed and the dose can be reduced per the clinician’s guidelines
- Drug interactions: avoid strong CYP3A inhibitors/inducers, as lurbinectedin is metabolized by CYP3A

Common side effects include myelosuppression (low white cells, red cells, platelets), nausea, vomiting, fatigue, liver enzyme elevations, diarrhea or constipation, and shortness of breath.

If you’re asking this for yourself or someone you know, the exact dosing and any needed adjustments should be determined by a doctor based on overall health, liver function, blood counts, and other meds. If you want, I can summarize the official prescribing information or look up specifics for hepatic impairment or prior therapies.