Lamotrigine with Escitalopram Interaction Details
Brand Names Associated with Lamotrigine
- Lamictal®
- Lamictal® CD
- Lamictal® ODT
- Lamictal® XR
- Lamotrigine
Brand Names Associated with Escitalopram
- Escitalopram
- Lexapro®
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Nov 10, 2023
Interaction Effect
An increased risk of myoclonus
Interaction Summary
Myoclonus occurred in 2 patients receiving escitalopram and lamotrigine concomitantly, where symptoms resolved following withdrawal of escitalopram in 1 patient. There was no evidence of a metabolic enzyme interaction with lamotrigine, and the interaction was believed to be due to an additive/synergistic effect of lamotrigine and escitalopram on the 5-HT1A receptors, or by an additive inhibition of voltage-gated calcium channels by both agents. Exercise caution when using both drugs concurrently and monitor for signs and symptoms of myoclonus including involuntary twitching and jerking.
Severity
Moderate
Onset
Delayed
Evidence
Probable
How To Manage Interaction
Use caution if escitalopram and lamotrigine are used concurrently as this resulted in myoclonus in 2 patients. In one patient, myoclonus resolved after escitalopram was withdrawn. Monitor for signs and symptoms of myoclonus including involuntary twitching and jerking.
Mechanism Of Interaction
Additive inhibition of voltage-gated calcium channels; additive or synergistic effects on the 5-HT1A receptor
Literature Reports
A) Myoclonus occurred in 2 patients following concomitant treatment with escitalopram and lamotrigine. The first patient, a 22-year-old woman taking escitalopram 30 mg/day for depression, developed daytime and nighttime myoclonus after 8 weeks of receiving lamotrigine (titrated to 100 mg/day) for the treatment of bipolar type II disorder. Serum levels of both drugs, measured after the onset of myoclonus, were within the expected drug reference ranges and escitalopram levels remained stable compared to a baseline level drawn prior to starting lamotrigine therapy. Neither drug was discontinued and the patient continued to have myoclonus while on escitalopram and lamotrigine therapy. Further analysis revealed that the patient was a normal metabolizer of CYP3A4, CYP2C19, and CYP2D6 enzymes. The second patient, a 28-year-old woman taking lamotrigine 300 mg/day for a seizure disorder, developed daytime and nighttime myoclonus after 2 weeks of receiving escitalopram (titrated to 20 mg/day) for generalized anxiety disorder. For 6 months, the patient experienced the same frequency of myoclonus while on both therapies; however, the myoclonus resolved 2 weeks after escitalopram was withdrawn. Lamotrigine serum levels, measured at the onset and after the myoclonus resolved, did not change. Although escitalopram is metabolized by hepatic enzymes CYP3A4, CYP2C19, and CYP2D6, there was no evidence of a metabolic enzyme interaction with lamotrigine. It was postulated that the myoclonus may have been caused by an additive or synergistic effect of lamotrigine and escitalopram on the 5-HT1A receptors, or by an additive inhibition of voltage-gated calcium channels by both agents .
Lamotrigine Overview
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Lamotrigine extended-release (long-acting) tablets are used with other medications to treat certain types of seizures in patients who have epilepsy. All types of lamotrigine tablets (tablets, orally disintegrating tablets, and chewable tablets) other than the extended-release tablets are used alone or with other medications to treat seizures in people who have epilepsy or Lennox-Gastaut syndrome (a disorder that causes seizures and often causes developmental delays). All types of lamotrigine tablets other than the extended-release tablets are also used to increase the time between episodes of depression, mania (frenzied or abnormally excited mood), and other abnormal moods in patients with bipolar I disorder (manic-depressive disorder; a disease that causes episodes of depression, episodes of mania, and other abnormal moods). Lamotrigine has not been shown to be effective when people experience the actual episodes of depression or mania, so other medications must be used to help people recover from these episodes. Lamotrigine is in a class of medications called anticonvulsants. It works by decreasing abnormal electrical activity in the brain.
Escitalopram Overview
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Escitalopram is used to treat depression in adults and children and teenagers 12 years of ago or older. Escitalopram is also used to treat generalized anxiety disorder (GAD; excessive worry and tension that disrupts daily life and lasts for 6 months or longer) in adults. Escitalopram is in a class of antidepressants called selective serotonin reuptake inhibitors (SSRIs). It works by increasing the amount of serotonin, a natural substance in the brain that helps maintain mental balance.
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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.