Drug interactions
Carbamazepine + Norgestimate
Severity: Major
Carbamazepine and Norgestimate: major interaction.
Last updated Sources: US FDA label
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 reduces circulating levels of norgestimate's active metabolites, undermining contraceptive efficacy. Breakthrough bleeding and unintended pregnancy may result.
What this interaction means in plain words
Carbamazepine and Norgestimate can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Why it happens
Carbamazepine induces CYP3A4 and other hepatic enzymes, accelerating metabolism of progestin and estrogen components.
What to do
Choose a non-enzyme-affected contraceptive such as an IUD or injectable medroxyprogesterone, or add condoms. Continue backup for 28 days after stopping carbamazepine.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Carbamazepine and Norgestimate, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
References
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 Norgestimate?
MediHelp rates the interaction as major. Carbamazepine and Norgestimate can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Carbamazepine reduces circulating levels of norgestimate's active metabolites, undermining contraceptive efficacy. Breakthrough bleeding and unintended pregnancy may result.
How serious is the interaction between Carbamazepine and Norgestimate?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Choose a non-enzyme-affected contraceptive such as an IUD or injectable medroxyprogesterone, or add condoms. Continue backup for 28 days after stopping carbamazepine.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
