Drug interactions
Sulfamethoxazole + Valganciclovir
Severity: Moderate
Sulfamethoxazole and Valganciclovir: 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
Sulfamethoxazole, usually given with trimethoprim, can cause myelosuppression, and ganciclovir also suppresses bone marrow. Combined use may increase the risk of neutropenia, anemia and thrombocytopenia.
What this interaction means in plain words
Sulfamethoxazole and Valganciclovir 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.
Why it happens
Additive bone marrow suppression.
What to do
Monitor complete blood counts regularly during combined therapy. Reduce or interrupt one agent if significant cytopenias develop.
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 Valganciclovir
Frequently asked questions
Can I take Sulfamethoxazole with Valganciclovir?
MediHelp rates the interaction as moderate. Sulfamethoxazole and Valganciclovir 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. Sulfamethoxazole, usually given with trimethoprim, can cause myelosuppression, and ganciclovir also suppresses bone marrow. Combined use may increase the risk of neutropenia, anemia and thrombocytopenia.
How serious is the interaction between Sulfamethoxazole and Valganciclovir?
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 regularly during combined therapy. Reduce or interrupt one agent if significant cytopenias develop.
What other medicines interact with Valganciclovir?
MediHelp also lists interactions of Valganciclovir with, for example, Didanosine, Ganciclovir, Liposomal doxorubicin. The full list is on the Valganciclovir page.
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