From the Guidelines
Namenda (memantine) is generally considered safe for patients with seizure disorders. It is primarily used to treat moderate to severe Alzheimer's disease and works as an NMDA receptor antagonist. Unlike some other medications that can lower the seizure threshold, memantine has not been shown to significantly increase seizure risk in most patients with epilepsy, as seen in various studies including those on neuropathic pain management 1. The typical dosing starts at 5 mg once daily and gradually increases to a target dose of 10 mg twice daily, with this slow titration helping to minimize side effects. Some key points to consider when prescribing Namenda to patients with seizure disorders include:
- The medication's mechanism of action as a moderate-affinity NMDA receptor antagonist helps regulate glutamate activity without the excessive blockade that could potentially trigger seizures, which explains its relatively favorable safety profile in seizure disorder patients.
- Patients with severe renal impairment may require dose adjustments.
- While using Namenda, patients should continue their regular antiepileptic medications as prescribed and inform their healthcare provider about any changes in seizure frequency or pattern. It's also worth noting that certain antiepileptic medications, such as carbamazepine, lamotrigine, oxcarbazepine, topiramate, and valproic acid, have been used for neuropathic pain management 1, but Namenda's unique mechanism and safety profile make it a viable option for patients with seizure disorders.
From the Research
Safety of Named Antiepileptic Drugs in Patients with Seizure Disorders
- The safety of antiepileptic drugs, such as lamotrigine, levetiracetam, and valproate, has been evaluated in several studies 2, 3, 4.
- A network meta-analysis of individual participant data found that levetiracetam performed significantly better than carbamazepine and lamotrigine in terms of time to withdrawal of allocated treatment for individuals with partial seizures 2.
- Another study found that lamotrigine, levetiracetam, and topiramate were as effective as valproate for treating generalized tonic-clonic, tonic, and clonic seizures 3.
- A randomized controlled trial found that valproate was superior to levetiracetam in terms of time to 12-month remission from seizures for patients with generalized or unclassifiable epilepsy 4.
Adverse Events Associated with Antiepileptic Drugs
- Common adverse events associated with antiepileptic drugs include drowsiness/fatigue, headache or migraine, gastrointestinal disturbances, dizziness/faintness, and rash or skin disorders 2.
- A study found that adverse reactions were reported by 33% of participants starting lamotrigine, 44% starting levetiracetam, and 45% starting zonisamide 4.
- Another study found that adverse reactions were reported by 37.4% of participants receiving valproate and 41.5% of those receiving levetiracetam 4.
Considerations for Improving Adherence to Antiepileptic Medications
- Extended-release and immediate-release anti-seizure medications with a long half-life may improve adherence by simplifying dosing regimens and reducing pill burden 5.
- Efforts to improve adherence should include therapeutic drug monitoring, improved healthcare provider-patient dialogue, patient education, and the use of "reminder" technology 5.
- A study found that delaying therapy until a second seizure does not affect one- to two-year remission rates, and treatment should begin with monotherapy 6.