Drug interactions
Carbamazepine + Sildenafil
Severity: Moderate
Carbamazepine and Sildenafil: 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
Carbamazepine is a strong inducer of CYP3A4, the main pathway of sildenafil metabolism. Sildenafil concentrations can fall substantially, leading to loss of therapeutic effect.
What this interaction means in plain words
Carbamazepine and Sildenafil 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.
Carbamazepine belongs to Central Nervous System; Sildenafil belongs to Genitourinary.
Why it happens
Carbamazepine induces CYP3A4, accelerating hepatic and intestinal metabolism of sildenafil.
What to do
Monitor for reduced response to sildenafil and consider a higher dose within labeled limits or an alternative agent. Reassess if carbamazepine is stopped.
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 Sildenafil
- Amyl nitrite + Sildenafil Contraindicated
- Atazanavir + Sildenafil Contraindicated
- Cobicistat + Sildenafil Contraindicated
- Elvitegravir / cobicistat / emtricitabine / tenofovir df + Sildenafil Contraindicated
- Glyceryl trinitrate pr + Sildenafil Contraindicated
- Isosorbide dinitrate + Sildenafil Contraindicated
Other interactions of Carbamazepine
- Artemether / lumefantrine + Carbamazepine Contraindicated
- Cabotegravir + Carbamazepine Contraindicated
- Carbamazepine + Delamanid Contraindicated
- Carbamazepine + Dienogest / estradiol valerate Contraindicated
- Carbamazepine + Doravirine Contraindicated
- Carbamazepine + Elbasvir / grazoprevir Contraindicated
Frequently asked questions
Can I take Carbamazepine with Sildenafil?
MediHelp rates the interaction as moderate. Carbamazepine and Sildenafil 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. Carbamazepine is a strong inducer of CYP3A4, the main pathway of sildenafil metabolism. Sildenafil concentrations can fall substantially, leading to loss of therapeutic effect.
How serious is the interaction between Carbamazepine and Sildenafil?
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 for reduced response to sildenafil and consider a higher dose within labeled limits or an alternative agent. Reassess if carbamazepine is stopped.
What other medicines interact with Sildenafil?
MediHelp also lists interactions of Sildenafil with, for example, Amyl nitrite, Atazanavir, Cobicistat. The full list is on the Sildenafil page.
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