Drug interactions
Cilastatin-imipenem + Valacyclovir
Severity: Moderate
Cilastatin-imipenem and Valacyclovir: 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
Seizures have been reported when ganciclovir is combined with imipenem-cilastatin, and valacyclovir's active metabolite acyclovir may carry a similar though less documented concern. Both drug classes can lower seizure threshold, especially in renal impairment.
What this interaction means in plain words
Cilastatin-imipenem and Valacyclovir 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.
Cilastatin-imipenem belongs to Anti Bacterial; Valacyclovir belongs to Anti Virals.
Why it happens
The mechanism is not established and is likely additive lowering of seizure threshold.
What to do
Dose-adjust both drugs for renal function and monitor for confusion, myoclonus or seizures. Consider alternatives in patients with a seizure history.
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 Cilastatin-imipenem
Other interactions of Valacyclovir
- Talimogene laherparepvec + Valacyclovir Major
- Bacitracin + Valacyclovir Moderate
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Valacyclovir Moderate
- Imipenem / cilastatin / relebactam + Valacyclovir Moderate
- Imipenem / cilastatin + Valacyclovir Moderate
- Mycophenolic acid + Valacyclovir Moderate
Frequently asked questions
Can I take Cilastatin-imipenem with Valacyclovir?
MediHelp rates the interaction as moderate. Cilastatin-imipenem and Valacyclovir 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. Seizures have been reported when ganciclovir is combined with imipenem-cilastatin, and valacyclovir's active metabolite acyclovir may carry a similar though less documented concern. Both drug classes can lower seizure threshold, especially in renal impairment.
How serious is the interaction between Cilastatin-imipenem and Valacyclovir?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Dose-adjust both drugs for renal function and monitor for confusion, myoclonus or seizures. Consider alternatives in patients with a seizure history.
What other medicines interact with Cilastatin-imipenem?
MediHelp also lists interactions of Cilastatin-imipenem with, for example, Divalproex, Ganciclovir, Valproic acid. The full list is on the Cilastatin-imipenem page.
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