Levofolinic acid (calcium levofolinate)

How it works

It is a reduced folate that bypasses dihydrofolate reductase to replenish intracellular folate pools (folinic rescue) and stabilises the binding of fluorouracil's active metabolite to thymidylate synthase.

Prescribing in practice

• When used as rescue after high-dose methotrexate, timely administration guided by methotrexate levels and renal function is critical to prevent serious toxicity.
• It must not be used to treat pernicious or other vitamin B12-deficiency anaemias because it can mask the haematological response while neurological damage progresses.
• Combined with fluorouracil it enhances both efficacy and toxicity, so fluorouracil-related adverse effects may require dose adjustment.

Monitoring

When used for methotrexate rescue, monitor methotrexate concentrations and renal function to determine the duration and intensity of folinic rescue.

Counselling the patient

• This medicine protects healthy cells from the effects of your chemotherapy.
• If used with fluorouracil, report severe diarrhoea, mouth soreness or signs of infection promptly.
• Take or attend for doses exactly as scheduled, as timing is important.

Evidence & guidelines

Folinic acid rescue after high-dose methotrexate and folinic acid modulation of fluorouracil are long-established standards of care in oncology.