Drug interactions
Ciprofloxacin + Fostemsavir
Severity: Moderate
Ciprofloxacin and Fostemsavir: 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
Both drugs can prolong the QTc interval, and fostemsavir has been linked to QT prolongation at supratherapeutic exposures. Combined use may add to the risk of ventricular arrhythmia, particularly in patients with other risk factors.
What this interaction means in plain words
Ciprofloxacin and Fostemsavir 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.
Ciprofloxacin belongs to Anti Bacterial; Fostemsavir belongs to Anti Virals.
Why it happens
Additive pharmacodynamic effect on cardiac repolarisation (QT prolongation).
What to do
Obtain a baseline ECG in patients with cardiac risk factors and correct potassium and magnesium before starting. Monitor the QTc while both are given and avoid exceeding recommended fostemsavir doses.
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 Ciprofloxacin
- Agomelatine + Ciprofloxacin Contraindicated
- Ciprofloxacin + Fezolinetant Contraindicated
- Ciprofloxacin + Thioridazine Contraindicated
- Ciprofloxacin + Tizanidine Contraindicated
- Ciprofloxacin + Vandetanib Contraindicated
- Alosetron + Ciprofloxacin Major
Other interactions of Fostemsavir
- Apalutamide + Fostemsavir Contraindicated
- Carbamazepine + Fostemsavir Contraindicated
- Enzalutamide + Fostemsavir Contraindicated
- Fostemsavir + Mitotane Contraindicated
- Fostemsavir + Phenytoin Contraindicated
- Fostemsavir + Rifampicin Contraindicated
Frequently asked questions
Can I take Ciprofloxacin with Fostemsavir?
MediHelp rates the interaction as moderate. Ciprofloxacin and Fostemsavir 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. Both drugs can prolong the QTc interval, and fostemsavir has been linked to QT prolongation at supratherapeutic exposures. Combined use may add to the risk of ventricular arrhythmia, particularly in patients with other risk factors.
How serious is the interaction between Ciprofloxacin and Fostemsavir?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Obtain a baseline ECG in patients with cardiac risk factors and correct potassium and magnesium before starting. Monitor the QTc while both are given and avoid exceeding recommended fostemsavir doses.
What other medicines interact with Ciprofloxacin?
MediHelp also lists interactions of Ciprofloxacin with, for example, Agomelatine, Fezolinetant, Thioridazine. The full list is on the Ciprofloxacin page.
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