Quetiapine with Carbamazepine Interaction Details
Brand Names Associated with Quetiapine
- Quetiapine
- Seroquel®
- Seroquel® XR
Brand Names Associated with Carbamazepine
- Carbamazepine
- Carbatrol®
- Epitol®
- Equetro®
- Tegretol®
- Tegretol®-XR
- Teril®
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Nov 25, 2023
Interaction Effect
Decreased quetiapine efficacy
Interaction Summary
Concomitant use of carbamazepine (CYP3A4 substrate and strong CYP3A4 inducer) and quetiapine (CYP3A4 inhibitor and substrate) may cause elevated carbamazepine levels and decreased quetiapine levels. Closely monitor carbamazepine levels and adjust the dose as necessary. Coadministration decreased quetiapine exposure and increased clearance in 1 study with effects lasting at least 3 weeks following carbamazepine withdrawal in a case report . Increase quetiapine dose up to 5 times the original dose when carbamazepine is used for more than 1 to 2 weeks and adjust as necessary; reduce to original dose within 1 to 2 week if carbamazepine is stopped .
Severity
Major
Onset
Delayed
Evidence
Established
How To Manage Interaction
Concomitant use of carbamazepine (CYP3A4 substrate and strong CYP3A4 inducer) and quetiapine (CYP3A4 inhibitor and substrate) may cause elevated carbamazepine levels. Closely monitor carbamazepine levels and adjust the dosage, if required. Coadministration may also result in decreased quetiapine exposure. Increase the dose of quetiapine up to 5 times the original dose when used in combination with carbamazepine for more than 1 to 2 weeks and then titrate based on the individual patient's needs. If carbamazepine is stopped, reduce the dose of quetiapine to the original level within 1 to 2 weeks . In a case report, the influence of carbamazepine induction of quetiapine's metabolism lasted at least 3 weeks following carbamazepine withdrawal .
Mechanism Of Interaction
Inhibition of CYP3A4-mediated carbamazepine metabolism by quetiapine; induction of CYP3A4-mediated quetiapine metabolism by carbamazepine
Literature Reports
A) In a case report, carbamazepine induction of quetiapine's metabolism lasted at least 3 weeks following carbamazepine withdrawal in a 30-year-old woman with mania. The patient was receiving stable carbamazepine 900 mg/day and lithium for more than 3 months for bipolar disorder. Quetiapine was initiated and titrated up to 1200 mg/day for the treatment of an episode of mania. Despite the high dosage of quetiapine, there was no clinical improvement and no serum quetiapine was detected (less than 20 nanograms (ng)/mL) at steady state. Carbamazepine was discontinued and quetiapine levels slowly began to increase; 38 ng/mL after 4 days, 67 ng/mL after 11 days, and 181 ng/mL after 16 days of carbamazepine withdrawal. The patient then experienced sedation and the quetiapine dosage was decreased to 600 mg/day, which resulted in serum level of 45 ng/mL following 25 days of carbamazepine withdrawal. One year later, her quetiapine level was 210 ng/mL, which was 4 times greater than 3 weeks after carbamazepine withdrawal .
B) In a 36-day, open-label, pharmacokinetic study of clinically stable psychiatric patients with schizophrenia, schizoaffective disorder, or bipolar disorder (n=18) receiving stable doses of quetiapine 300 mg twice daily and subsequently titrated to carbamazepine 200 mg 3 times daily over 2 weeks, experienced a decrease in quetiapine AUC and Cmax, and an increase in clearance. Coadministration at day 34 decreased the Cmax of quetiapine by 80% from 1042 to 205 nanograms (ng)/mL and decreased AUC from 4650 to 621 ng x hr/mL. Quetiapine clearance increased 7.5-fold from 65 to 483 L/hr .
Quetiapine Overview
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Quetiapine tablets and extended-release (long-acting) tablets are used to treat the symptoms of schizophrenia (a mental illness that causes disturbed or unusual thinking, loss of interest in life, and strong or inappropriate emotions). Quetiapine tablets and extended-release tablets are also used alone or with other medications to treat episodes of mania (frenzied, abnormally excited or irritated mood) or depression in patients with bipolar disorder (manic depressive disorder; a disease that causes episodes of depression, episodes of mania, and other abnormal moods). In addition, quetiapine tablets and extended-release tablets are used with other medications to prevent episodes of mania or depression in patients with bipolar disorder. Quetiapine extended-release tablets are also used along with other medications to treat depression. Quetiapine tablets may be used as part of a treatment program to treat bipolar disorder and schizophrenia in children and teenagers. Quetiapine is in a class of medications called atypical antipsychotics. It works by changing the activity of certain natural substances in the brain.
Carbamazepine Overview
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Carbamazepine is used alone or in combination with other medications to control certain types of seizures in people with epilepsy. It is also used to treat trigeminal neuralgia (a condition that causes facial nerve pain). Carbamazepine extended-release capsules (Equetro brand only) are also used to treat episodes of mania (frenzied, abnormally excited or irritated mood) or mixed episodes (symptoms of mania and depression that happen at the same time) in patients with bipolar I disorder (manic-depressive disorder; a disease that causes episodes of depression, episodes of mania, and other abnormal moods). Carbamazepine is in a class of medications called anticonvulsants. It works by reducing abnormal electrical activity in the brain.
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Definitions
Severity Categories
Contraindicated
These drugs, generally, should not be used together simultaneously due to the high risk of severe adverse effects. Combining these medications can lead to dangerous health outcomes and should be strictly avoided unless otherwise instructed by your provider.
Major
This interaction could result in very serious and potentially life-threatening consequences. If you are taking this drug combination, it is very important to be under close medical supervision to minimize severe side effects and ensure your safety. It may be necessary to change a medication or dosage to prevent harm.
Moderate
This interaction has the potential to worsen your medical condition or alter the effectiveness of your treatment. It's important that you are monitored closely and you potentially may need to make adjustments in your treatment plan or drug dosage to maintain optimal health.
Minor
While this interaction is unlikely to cause significant problems, it could intensify side effects or reduce the effectiveness of one or both medications. Monitoring for changes in symptoms and your condition is recommended, and adjustments may be made if needed to manage any increased or more pronounced side effects.
Onset
Rapid: Onset of drug interaction typically occurs within 24 hours of co-administration.
Delayed: Onset of drug interaction typically occurs more than 24 hours after co-administration.
Evidence
Level of documentation of the interaction.
Established: The interaction is documented and substantiated in peer-reviewed medical literature.
Theoretical: This interaction is not fully supported by current medical evidence or well-documented sources, but it is based on known drug mechanisms, drug effects, and other relevant information.
How To Manage The Interaction
Provides a detailed discussion on how patients and clinicians can approach the identified drug interaction as well as offers guidance on what to expect and strategies to potentially mitigate the effects of the interaction. This may include recommendations on adjusting medication dosages, altering the timing of drug administration, or closely monitoring for specific symptoms.
It's important to note that all medical situations are unique, and management approaches should be tailored to individual circumstances. Patients should always consult their healthcare provider for personalized advice and guidance on managing drug interactions effectively.
Mechanism Of Interaction
The theorized or clinically determined reason (i.e., mechanism) why the drug-drug interaction occurs.
Disclaimer: The information provided on this page is for informational purposes only and should not be considered medical advice. Always consult with a qualified healthcare professional regarding your specific circumstances and medical conditions.
Where Does Our Information Come From?
Information for our drug interactions is compiled from several drug compendia, including:
The prescribing information for each drug, as published on DailyMED, is also used.
Individual drug-drug interaction detail pages contain references specific to that interaction. You can click on the reference number within brackets '[]' to see what reference was utilized.
The information posted is fact-checked by HelloPharmacist clinicians and reviewed quarterly.