Ropinirole with Warfarin Interaction Details
Brand Names Associated with Ropinirole
- Requip®
- Requip® XL
- Ropinirole
Brand Names Associated with Warfarin
- Coumadin®
- Jantoven®
- Warfarin
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Dec 03, 2023
Interaction Effect
An increase in INR
Interaction Summary
Use caution with the coadministration of rOPINIRole and warfarin as this led to an increase in INR as described in a case report. The mechanism of this interaction is theorized to be either competitive inhibition of the CYP1A2-mediated warfarin metabolism and/or the displacement of warfarin from protein binding sites by rOPINIRole. Increased INR monitoring is recommended when rOPINIRole therapy is required concurrently with warfarin therapy. Additionally, if rOPINIRole therapy is discontinued, consider increased INR monitoring to prevent a subtherapeutic INR and adjust the warfarin dose appropriately.
Severity
Major
Onset
Delayed
Evidence
Probable
How To Manage Interaction
Because the observed interaction resulted in an increased INR, practitioners should consider monitoring INR more frequently if rOPINIRole therapy is initiated or adjusted in a patient stabilized on warfarin. Additionally, if a patient discontinues rOPINIRole while concomitantly on warfarin, consider frequent INR monitoring and adjust the warfarin dose as needed.
Mechanism Of Interaction
Competitive inhibition of CYP1A2-mediated warfarin metabolism and/or displacement of warfarin by rOPINIRole from protein binding sites
Literature Reports
A) A case report described an increase in INR without reported bleeding events after initiation of rOPINIRole for progressing Parkinson's disease in a 63-year-old male stabilized on warfarin. The patient, who also had Alzheimer's disease and was status post-cardiovascular accident (3 years), was maintained on levodopa 25 mg/carbidopa 250 mg (4 tablets/day), doxazosin 4 mg/day, and warfarin 4 mg/day. Three months prior to initiation of rOPINIRole, the patient's INR was therapeutic at 2.1 and had been stable for over a year, with no changes in warfarin dosage. Nine days after the start of rOPINIRole 0.25 mg three times daily, the patient's INR increased to 4.6. The patient denied any changes in diet, nonprescription product use, herbal product use, or alcohol use. Warfarin was withheld for 4 days and then the dose was reduced by 50%, causing the INR to drop to 1.2. The warfarin dose was increased to 75% of the pre-rOPINIRole dose and the INR became therapeutic at 1.7. ROPINIRole was discontinued 1 month later due to gastrointestinal adverse effects. Subsequently, the patient's INR became subtherapeutic again necessitating the return to the original warfarin dose (4 mg/day). The interaction was rated as probable based on the Naranjo probability scale. Postulated mechanisms were either competitive inhibition of the CYP1A2-mediated warfarin metabolism by rOPINIRole, thereby resulting in accumulation of R-warfarin, and/or displacement of warfarin by rOPINIRole from protein binding sites .
Ropinirole Overview
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Ropinirole is used alone or with other medications to treat the symptoms of Parkinson's disease (PD; a disorder of the nervous system that causes difficulties with movement, muscle control, and balance), including shaking of parts of the body, stiffness, slowed movements, and problems with balance. Ropinirole is also used to treat restless legs syndrome (RLS or Ekbom syndrome; a condition that causes discomfort in the legs and a strong urge to move the legs, especially at night and when sitting or lying down). Ropinirole is in a class of medications called dopamine agonists. It works by acting in place of dopamine, a natural substance in the brain that is needed to control movement.
Warfarin Overview
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Warfarin is used to prevent blood clots from forming or growing larger in your blood and blood vessels. It is prescribed for people with certain types of irregular heartbeat, people with prosthetic (replacement or mechanical) heart valves, and people who have suffered a heart attack. Warfarin is also used to treat or prevent venous thrombosis (swelling and blood clot in a vein) and pulmonary embolism (a blood clot in the lung). Warfarin is in a class of medications called anticoagulants ('blood thinners'). It works by decreasing the clotting ability of the blood.
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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.