From the Guidelines
The medication amantadine should be discontinued immediately if a patient experiences decreased mentation, falls, and confusion after starting it for Parkinson's disease, as these symptoms suggest severe central nervous system side effects. These side effects, as noted in the study by 1, can include marked behavioral changes, delirium, hallucinations, agitation, and seizures, particularly in elderly patients or those with renal insufficiency. While waiting to speak with the healthcare provider, it is crucial to ensure the patient is in a safe environment to prevent injury from falls. The patient should be monitored closely for improvement of symptoms after discontinuation.
The decision to discontinue amantadine is based on the potential for serious side effects associated with its use, especially in vulnerable populations such as the elderly or those with renal impairment, as highlighted by 1. This study suggests that for persons aged >65 years, the daily dose of amantadine should not exceed 100 mg for prophylaxis or treatment due to declining renal function with age. However, in the context of managing Parkinson's disease, if such side effects occur, the priority should be to prevent further harm.
Key considerations include:
- Ensuring patient safety to prevent falls and injuries
- Monitoring for improvement of symptoms after discontinuing amantadine
- Assessing renal function, as amantadine is primarily excreted by the kidneys
- Considering alternative medications for Parkinson's disease management, such as levodopa/carbidopa, dopamine agonists, or MAO-B inhibitors, depending on the patient's specific needs and tolerability, as guided by the healthcare provider.
From the FDA Drug Label
Patients who attempt suicide may exhibit abnormal mental states which include disorientation, confusion, depression, personality changes, agitation, aggressive behavior, hallucinations, paranoia, other psychotic reactions, and somnolence or insomnia Blurry vision, eye pain, loss of vision and/or impaired mental acuity may occur Avoid excessive alcohol usage, since it may increase the potential for CNS effects such as dizziness, confusion, lightheadedness and orthostatic hypotension.
The patient is experiencing decreased mentation, falls, and confusion after starting amantadine, which may be related to the CNS effects of the medication.
- Key considerations:
- The patient may be experiencing abnormal mental states due to amantadine, including disorientation, confusion, and impaired mental acuity.
- Corneal edema has been reported in patients taking amantadine, which can cause blurry vision and eye pain.
- Excessive alcohol usage may increase the potential for CNS effects.
- Recommendation:
- Notify the physician immediately, as these symptoms may be related to the medication.
- Consider discontinuing amantadine and ruling out other etiologies if corneal edema is suspected.
- Monitor the patient closely for increased seizure activity, congestive heart failure, and other adverse effects.
- Adjust the dose or stop the medication if the patient develops intense urges or other adverse effects while taking amantadine hydrochloride 2 2.
From the Research
Decreased Mentation, Falls, and Confusion after Starting Amantadine
- The symptoms of decreased mentation, falls, and confusion in a patient after starting amantadine for Parkinson's disease could be related to the medication itself or its withdrawal 3, 4.
- Amantadine is known to cause adverse effects such as hallucinations, and its withdrawal can lead to severe delirium, even in patients without prior cognitive impairment 3.
- The pharmacokinetics of amantadine can be affected by renal function, and patients with impaired renal function may experience longer half-lives of elimination, potentially increasing the risk of adverse effects 5.
- There is no direct evidence in the provided studies that links amantadine to decreased mentation, falls, and confusion as a specific side effect. However, the medication's impact on the central nervous system and its potential to cause delirium suggests that it could contribute to such symptoms 4.
- It is essential to consider the patient's overall medical condition, including renal function and other medications, when evaluating the cause of these symptoms and determining the best course of action 5, 6.
- The studies provided do not offer specific guidance on managing decreased mentation, falls, and confusion in patients taking amantadine but highlight the importance of careful medication management and monitoring for potential adverse effects 3, 5, 4, 7, 6.