Lamotrigine with Risperidone Interaction Details

Brand Names Associated with Lamotrigine

Brand Names Associated with Risperidone

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated Nov 08, 2023

Interaction Effect

Increased risk of somnolence

Interaction Summary

Clinicians should be aware of the increased risk adverse effects in patients receiving lamotrigine together with risperiDONE. An increased incidence of somnolence was observed when lamotrigine was coadministered with risperiDONE compared with either agent alone. Although lamotrigine had no clinically significant effect on risperiDONE pharmacokinetics in 14 healthy volunteers,, increased risperiDONE plasma concentrations, with signs of toxicity, developed in one patient administered lamotrigine in addition to a stable dose-regimen of risperiDONE and clozapine .

Severity

Moderate

Onset

Delayed

Evidence

Established

How To Manage Interaction

Clinicians should be aware of the increased risk of adverse effects in patients receiving lamotrigine together with risperiDONE. An increased incidence of somnolence was observed when lamotrigine was coadministered with risperiDONE compared with either agent alone.

Mechanism Of Interaction

Unknown

Literature Reports

A) In a pharmacokinetic study of 14 healthy volunteers, multiple doses of lamotrigine 400 mg had no clinically significant effect on the single-dose pharmacokinetic parameters for risperiDONE. However, an increased incidence of somnolence was observed when lamotrigine was coadministered with risperidone 2 mg (12 of 14 subjects) compared with risperidone alone (1 of 20 subjects) or lamotrigine alone (0 subjects) .

B) Increased risperiDONE plasma concentrations and subsequent toxicity were reported in a 26-year-old woman receiving lamotrigine in addition to a stable dose-regimen of risperiDONE and clozapine. The patient was diagnosed with schizophrenia, had sustained only a partial response to her established regimen of clozapine 550 mg daily and risperiDONE 8 mg daily. Baseline plasma concentrations of risperiDONE and clozapine were 55 to 70 nanograms/mL (ng/mL; 134 to 171 nanomoles/L (nmol/L)) and 800 to 1100 ng/mL (2448 to 3336 nmol/L), respectively. Lamotrigine was initiated, with the dose incrementally titrated up to 200 mg daily. Clozapine and risperiDONE plasma concentrations increased to 1300 ng/mL (3978 nmol/L) and 263 ng/mL (641 nmol/L); no symptoms of intoxication were observed. Lamotrigine was further titrated up to a dose of 225 mg daily, after which risperiDONE plasma concentration increased to 412 ng/mL (1004 nmol/L), accompanied by symptoms of dizziness and tiredness. The risperiDONE dose was reduced to 2 mg daily and completely withdrawn shortly thereafter .

Lamotrigine Overview

• 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.

Risperidone Overview

• Risperidone is 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) in adults and teenagers 13 years of age and older. It is also used to treat episodes of mania (frenzied, abnormally excited, or irritated mood) or mixed episodes (symptoms of mania and depression that happen together) in adults and in teenagers and children 10 years of age and older with bipolar disorder (manic depressive disorder; a disease that causes episodes of depression, episodes of mania, and other abnormal moods). Risperidone is also used to treat behavior problems such as aggression, self-injury, and sudden mood changes in teenagers and children 5 to 16 years of age who have autism (a condition that causes repetitive behavior, difficulty interacting with others, and problems with communication). Risperidone is in a class of medications called atypical antipsychotics. It works by changing the activity of certain natural substances 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:

• Gold Standard Drug Database
• Micromedex
• Lexicomp
• DrugBank

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.