From the Guidelines
Hydroxychloroquine's effect on the seizure threshold is not directly addressed in the provided evidence, and therefore, its impact on seizure threshold cannot be definitively determined from the given studies. The provided evidence discusses various medications and their potential to lower the seizure threshold, such as zanamivir, oseltamivir, amantadine, and rimantadine 1, as well as the management of seizures in emergency departments 1. However, hydroxychloroquine is not mentioned in these studies.
Given the lack of direct evidence, it is essential to consider the potential risks and benefits of hydroxychloroquine in patients with seizure disorders. Some medications, like tramadol and cocaine, are known to lower the seizure threshold 1. If hydroxychloroquine were to have a similar effect, it would be crucial to monitor patients closely for seizure activity.
- Key considerations for healthcare providers include:
- Careful risk assessment before prescribing hydroxychloroquine to patients with a history of seizures
- Monitoring patients for neurological symptoms that might precede seizure activity
- Adjusting the typical dosing of hydroxychloroquine (200-400 mg daily) in patients with risk factors, such as pre-existing seizure disorders, central nervous system disorders, or renal impairment
- Discontinuing hydroxychloroquine and considering alternative treatments if a patient experiences a seizure while on the medication
It is crucial to rely on the most recent and highest-quality studies when making definitive recommendations. In this case, the lack of direct evidence regarding hydroxychloroquine's effect on the seizure threshold means that healthcare providers must exercise caution and consider the potential risks and benefits when prescribing this medication to patients with seizure disorders 1.
From the FDA Drug Label
- 3 Drugs that Lower the Seizure Threshold Hydroxychloroquine sulfate can lower the seizure threshold. Co-administration of hydroxychloroquine sulfate with other antimalarials known to lower the seizure threshold (e.g., mefloquine) may increase the risk of seizures.
Hydroxychloroquine can lower the seizure threshold. This is a direct effect of the drug, and co-administration with other drugs that also lower the seizure threshold may increase the risk of seizures 2.
From the Research
Hydroxychloroquine and Seizure Threshold
- The relationship between hydroxychloroquine and seizure threshold is a topic of interest, with some studies suggesting a potential link between the two.
- A systematic review of published literature on chloroquine or hydroxychloroquine therapy in persons with and without epilepsy found no substantial evidence to suggest that these medications can increase seizure risk 3.
- However, a case report of a 17-year-old female with systemic lupus erythematosus (SLE) who developed a tonicoclonic crisis after receiving hydroxychloroquine for 2 weeks at a dosage of 200 mg/day suggests that hydroxychloroquine may be responsible for tonicoclonic seizures in predisposed subjects 4.
- Other studies have investigated the effects of antiepileptic drugs on serum immunoglobulin levels in children 5 and the seizure-lowering effects of antipsychotic medication 6, but these studies do not provide direct evidence on the relationship between hydroxychloroquine and seizure threshold.
- A network meta-analysis of individual participant data on antiepileptic drug monotherapy for epilepsy found that levetiracetam performed significantly better than current first-line treatment carbamazepine and other current first-line treatment lamotrigine performed better than all other treatments (aside from levetiracetam) 7, but this study does not provide information on hydroxychloroquine.
Key Findings
- There is limited evidence to suggest that hydroxychloroquine lowers the seizure threshold.
- A systematic review found no substantial evidence to support a link between hydroxychloroquine and increased seizure risk 3.
- A case report suggests that hydroxychloroquine may be responsible for tonicoclonic seizures in predisposed subjects 4.
- Further research is needed to fully understand the relationship between hydroxychloroquine and seizure threshold.