Drug interactions
Cyclophosphamide + Hydrochlorothiazide
Severity: Moderate
Cyclophosphamide and Hydrochlorothiazide: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Thiazide diuretics may increase the myelosuppressive effect of cyclophosphamide, leading to deeper or prolonged leukopenia. The effect is usually manageable with blood count monitoring.
What this interaction means in plain words
Cyclophosphamide and Hydrochlorothiazide can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Cyclophosphamide belongs to Oncology; Hydrochlorothiazide belongs to Cardiovascular.
Why it happens
Thiazides may reduce renal clearance of cyclophosphamide and its metabolites, increasing exposure.
What to do
Monitor complete blood counts closely after starting or changing the thiazide. Reduce the cyclophosphamide dose if marked myelosuppression occurs.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Cyclophosphamide
Other interactions of Hydrochlorothiazide
Frequently asked questions
Can I take Cyclophosphamide with Hydrochlorothiazide?
MediHelp rates the interaction as moderate. Cyclophosphamide and Hydrochlorothiazide can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Thiazide diuretics may increase the myelosuppressive effect of cyclophosphamide, leading to deeper or prolonged leukopenia. The effect is usually manageable with blood count monitoring.
How serious is the interaction between Cyclophosphamide and Hydrochlorothiazide?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor complete blood counts closely after starting or changing the thiazide. Reduce the cyclophosphamide dose if marked myelosuppression occurs.
What other medicines interact with Cyclophosphamide?
MediHelp also lists interactions of Cyclophosphamide with, for example, Adenovirus types 4 and 7 live, Belatacept, Bendamustine. The full list is on the Cyclophosphamide page.
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