From the Guidelines
Dextromethorphan is not recommended for treating Posterior Reversible Encephalopathy Syndrome (PRES) caused by methotrexate. The standard treatment for methotrexate-induced PRES involves immediate discontinuation of methotrexate, blood pressure control if hypertension is present, and supportive care, as suggested by the ESMO-EONS-EANO clinical practice guidelines for diagnosis, prevention, treatment, and follow-up of systemic anticancer therapy-induced peripheral and central neurotoxicity 1.
Key Considerations
- The treatment of PRES is purely symptomatic and includes discontinuation of the offending agent, correction of electrolytes, and symptomatic treatment with benzodiazepines, for example, if necessary 1.
- Very stringent control of blood pressure is crucial, especially when PRES is present, and treatment requires cessation of anticancer therapy and antiepileptic treatment in case of seizures 1.
- PRES is usually reversible with appropriate supportive management within 2 weeks, and a reintroduction of the prior anticancer therapy has to be decided on an individual basis 1.
Management Approach
- Discontinuation of methotrexate is the first step in managing PRES caused by this agent.
- Blood pressure control is essential to prevent further endothelial injury and disruption of the blood-brain barrier.
- Supportive care, including management of seizures with anticonvulsants if necessary, is critical until the condition resolves.
- Dextromethorphan, primarily used as a cough suppressant, has no established role in the management of PRES, as the pathophysiology involves endothelial dysfunction and disruption of the blood-brain barrier leading to vasogenic edema, which is not directly addressed by dextromethorphan 1.
Monitoring and Follow-Up
- Close neurological monitoring and follow-up imaging are essential to confirm resolution of the brain edema and to guide the management of the patient.
- The decision to reintroduce methotrexate or any other anticancer therapy should be made cautiously and based on individual patient assessment, considering the risk of recurrent PRES and the potential benefits of the therapy.
From the Research
Dextromethorphan Treatment for PRES due to Methotrexate
- There is limited research directly addressing the use of dextromethorphan for treating Posterior Reversible Encephalopathy Syndrome (PRES) caused by methotrexate.
- A study from 2 describes a case of methotrexate-induced PRES in an adult, highlighting the importance of considering this condition in the differential diagnosis of acute neurological changes in patients receiving methotrexate.
- Research on dextromethorphan's neuroprotective effects is available, with studies suggesting its potential in treating various neurological disorders, including those involving neurotoxicity and inflammation 3, 4, 5.
- Specifically, dextromethorphan has been shown to provide neuroprotection via anti-inflammatory and anti-excitotoxicity effects in the cortex following traumatic brain injury 3.
- Its potential in treating methotrexate neurotoxicity is mentioned in 4 and 5, indicating some promise for its use in conditions involving neurotoxicity.
- However, the clinical efficacy of dextromethorphan in treating PRES due to methotrexate is not directly established in the provided studies.
- Further research is needed to explore the therapeutic potential of dextromethorphan in this specific context, considering its mechanisms of action and the pathophysiology of methotrexate-induced PRES.