Drug interactions
Carbamazepine + Sulfamethoxazole
Severity: Minor
Carbamazepine and Sulfamethoxazole: minor 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 may modestly reduce sulfamethoxazole exposure, though the clinical importance is unclear. Both drugs can also cause hematologic toxicity and hypersensitivity reactions.
What this interaction means in plain words
Carbamazepine and Sulfamethoxazole have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Carbamazepine may induce CYP2C9-mediated sulfamethoxazole metabolism; evidence is limited.
What to do
No dose change is usually required. Monitor blood counts and watch for rash or reduced antibacterial response.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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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 Sulfamethoxazole?
MediHelp rates the interaction as minor. Carbamazepine and Sulfamethoxazole have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Carbamazepine may modestly reduce sulfamethoxazole exposure, though the clinical importance is unclear. Both drugs can also cause hematologic toxicity and hypersensitivity reactions.
How serious is the interaction between Carbamazepine and Sulfamethoxazole?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No dose change is usually required. Monitor blood counts and watch for rash or reduced antibacterial response.
What other medicines interact with Carbamazepine?
MediHelp also lists interactions of Carbamazepine with, for example, Artemether / lumefantrine, Cabotegravir, Delamanid. The full list is on the Carbamazepine page.
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