Cyclophosphamide and Filgrastim: Drug Interaction Guide

Quick answer: This combination requires caution. Cyclophosphamide and Filgrastim can be used together with adjustments and monitoring.

Interaction severity: Moderate — caution required

How Cyclophosphamide interacts with Filgrastim

G-CSF (filgrastim) mobilises proliferating myeloid precursors that are highly sensitive to cyclophosphamide-induced DNA alkylation, potentially worsening cytopenia and pulmonary toxicity if given simultaneously.

What you should do

Do not administer filgrastim within 24 hours of cytotoxic chemotherapy. Schedule G-CSF starting 24-72 hours after cyclophosphamide completion.

Key facts

Severity

Moderate — caution required

Mechanism

G-CSF (filgrastim) mobilises proliferating myeloid precursors that are highly sensitive to cyclophosphamide-induced DNA ...

Action

Do not administer filgrastim within 24 hours of cytotoxic chemotherapy. Schedule G-CSF starting 24-72 hours after cyclop...

Important medical disclaimer: This page provides educational information about drug interactions for general reference. It is not a substitute for professional medical advice, diagnosis, or treatment. Always discuss your specific medications with a qualified healthcare provider before starting, stopping, or changing any treatment. About our editorial team.

Frequently asked questions

Can I take Cyclophosphamide and Filgrastim together?

With caution. Do not administer filgrastim within 24 hours of cytotoxic chemotherapy. Schedule G-CSF starting 24-72 hours after cyclophosphamide completion.

What is the severity of this interaction?

The interaction between Cyclophosphamide and Filgrastim is classified as Moderate — caution required. G-CSF (filgrastim) mobilises proliferating myeloid precursors that are highly sensitive to cyclophosphamide-induced DNA alkylation, potentially worsening cytopenia and pulmonary toxicity if given simultaneously.

What should I do if I'm prescribed both?

Do not administer filgrastim within 24 hours of cytotoxic chemotherapy. Schedule G-CSF starting 24-72 hours after cyclophosphamide completion. Always consult your prescribing clinician — do not stop or change medications without medical guidance.

Last reviewed: by iMedic Medical Editorial Team. Our editorial process.