Risperidone with Primidone Interaction Details

Brand Names Associated with Risperidone

Brand Names Associated with Primidone

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

Interaction Effect

An increased risk of QT interval prolongation, reduced risperiDONE exposure, reduced 9-hydroxyrisperiDONE exposure and reduced efficacy of risperiDONE

Interaction Summary

Coadministration of PHENobarbital and risperiDONE may lead to decreased risperiDONE and 9-hydroxyrisperiDONE exposure. If PHENobarbital is initiated, closely monitor during the first 4 to 8 weeks. In patients receiving PERSERIS(TM) 90 mg or UZEDY(TM), consider increasing to the next highest dose. In patients receiving PERSERIS(TM) 120 mg or UZEDY(TM) 125 mg once monthly or 250 mg once every 2 months, additional oral risperiDONE may be necessary. Upon discontinuation of PHENobarbital, re-evaluate risperiDONE dosage and decrease as necessary. If patients are receiving risperiDONE 25 mg IM, PERSERIS(TM) 90 mg or UZEDY(TM) 50 mg once monthly or 100 mg once every 2 months, treatment may be continued unless the clinician deems it necessary to interrupt risperiDONE 12.5 mg IM dose may be considered, but efficacy is not established. Also, avoid the concomitant use of PHENobarbital with risperiDONE as it may result in additive QTc interval prolongation. If unavoidable, monitor patients for increased risk of QTc interval prolongation .

Severity

Major

Onset

Unspecified

Evidence

Probable

How To Manage Interaction

Coadministration of PHENobarbital and risperiDONE may lead to decreased risperiDONE and 9-hydroxyrisperiDONE exposure. If PHENobarbital is initiated, closely monitor during the first 4 to 8 weeks. In patients receiving PERSERIS(TM) 90 mg or UZEDY(TM), consider increasing to the next highest dose. In patients receiving PERSERIS(TM) 120 mg or UZEDY(TM) 125 mg once monthly or 250 mg once every 2 months, additional oral risperiDONE may be necessary. Upon discontinuation of PHENobarbital, re-evaluate risperiDONE dosage and decrease as necessary. If patients are receiving risperiDONE 25 mg IM, PERSERIS(TM) 90 mg or UZEDY(TM) 50 mg once monthly or 100 mg once every 2 months, treatment may be continued unless the clinician deems it necessary to interrupt; a risperiDONE 12.5 mg IM dose may be considered, but efficacy is not established.. Also, avoid the concomitant use of PHENobarbital with risperiDONE as it may result in additive QTc interval prolongation. If unavoidable, monitor patients for increased risk of QTc interval prolongation .

Mechanism Of Interaction

Additive QT interval prolongation; induction of CYP3A-mediated metabolism of risperiDONE by PHENobarbital

Literature Reports

A) In a drug interaction study, carBAMazepine coadministered with oral risperiDONE decreased the steady-state plasma concentrations of risperiDONE and 9-hydroxyrisperiDONE by about 50%. Plasma concentrations of carBAMazepine did not appear to be affected. Coadministration of other known CYP3A4 enzyme inducers (e.g., phenytoin, rifAMPin, and PHENobarbital) with risperiDONE may cause similar decreases in the combined plasma concentrations of risperidone and 9-hydroxyrisperiDONE, which could lead to decreased efficacy of risperiDONE .

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.

Primidone Overview

• Primidone is used alone or with other medications to control certain types of seizures. Primidone is in a class of medications called anticonvulsants. It works by decreasing 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:

• 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.