Antiepilepsy Drug Rufinamide Tied to Weight Loss

August 28, 2012

By Frederik Joelving

NEW YORK (Reuters Health) Aug 24 - Nearly half of the patients taking rufinamide for epilepsy in a new case series developed clinically significant weight loss, according to French researchers.

Rufinamide (Banzel) is approved as add-on treatment for Lennox-Gastaut syndrome, a severe form of childhood-onset epilepsy. Weight loss has not been described in clinical trials of the drug. Still, clinicians should be aware of the potential side effect, said Dr. Isabelle Mourand and Dr. Philippe Gelisse, who worked on the new report.

"Supervision of the BMI before and during treatment appears necessary," they told Reuters Health by email. "Moreover, lower starting doses and slower escalation could be recommended."

In a paper published online July 10 in Epilepsia, the researchers describe 15 consecutive adults taking rufinamide (mean dose, 1,886 mg/day) for refractory epilepsy. All were taking lamotrigine as well; four were on valproate, three on zonisamide and three on topiramate.

Seven patients experienced "clinically significant" weight loss, with BMI drops ranging from 7.3% to 18.7% (3.7 kg to 14 kg). Most attributed their weight changes to appetite loss with or without nausea, and four stopped taking rufinamide as a result.

All except one of the patients who discontinued rufinamide saw their weight increase following drug cessation.

Dr. Mourand and Dr. Gelisse, who has been a paid consultant to Eisai Inc, the manufacturer of rufinamide, said they have seen significant weight loss in three new patients since their report.

"In our opinion further research should examine whether there is any relationship between rufinamide dose/blood level and weight loss," they added. "It would be interesting to know whether weight loss with rufinamide can be explained by pharmacodynamic or pharmacokinetic interaction with other antiepileptic drugs."

Dr. Yu-tze Ng, director of epilepsy at the University of Oklahoma College of Medicine in Oklahoma City, said he had not heard of the link between rufinamide and weight loss before seeing the new report -- although several of his patients on rufinamide have suffered gastrointestinal side effects.

He noted that all except one patient who lost weight were also taking topiramate or zonisamide, which themselves have been associated with BMI decreases.

Still, he said the link between rufinamide and weight loss is credible given that the patients' weight was stable before they started on the drug.

"This could be an additional consideration when selecting the correct AED (antiepileptic drug)... for the next patient with epilepsy, with Lennox-Gastaut syndrome or not," Dr. Ng told Reuters Health by email. "Although in general weight loss is desirable in adults, more often than not this can be undesirable in a small child."


Epilepsia 2012.


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