Drug interactions
Carbamazepine + Hydrochlorothiazide
Severity: Moderate
Carbamazepine and Hydrochlorothiazide: 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 lower serum sodium, so combined use increases the risk of clinically significant hyponatremia. Symptoms range from nausea and confusion to seizures, and older patients are at higher risk.
What this interaction means in plain words
Carbamazepine and Hydrochlorothiazide 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; Hydrochlorothiazide belongs to Cardiovascular.
Why it happens
Additive hyponatremia through thiazide-induced renal sodium loss and carbamazepine-related antidiuretic effect (SIADH-like).
What to do
Check serum sodium before starting and periodically thereafter, particularly in the first weeks. Stop or change the diuretic if sodium falls significantly or symptoms occur.
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 Hydrochlorothiazide
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 Hydrochlorothiazide?
MediHelp rates the interaction as moderate. Carbamazepine and Hydrochlorothiazide 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 lower serum sodium, so combined use increases the risk of clinically significant hyponatremia. Symptoms range from nausea and confusion to seizures, and older patients are at higher risk.
How serious is the interaction between Carbamazepine and Hydrochlorothiazide?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check serum sodium before starting and periodically thereafter, particularly in the first weeks. Stop or change the diuretic if sodium falls significantly or symptoms occur.
What other medicines interact with Hydrochlorothiazide?
MediHelp also lists interactions of Hydrochlorothiazide with, for example, Dofetilide, Amifostine, Amiodarone. The full list is on the Hydrochlorothiazide page.
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