Urolithiasis on the ketogenic diet with concurrent topiramate or zonisamide therapy

• Published in: Epilepsy research Vol. 90; no. 1; pp. 151 - 156
• Main Authors: Paul, Elahna, Conant, Kerry D, Dunne, Irie E, Pfeifer, Heidi H, Lyczkowski, David A, Linshaw, Michael A, Thiele, Elizabeth A
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.06.2010; Elsevier
• Subjects: Anticonvulsants - adverse effects; Biological and medical sciences; Child; Child, Preschool; Combined Modality Therapy - adverse effects; Diet, Ketogenic - adverse effects; Diseases of the nervous system; Epilepsy; Epilepsy - diet therapy; Epilepsy - drug therapy; Female; Fructose - adverse effects; Fructose - analogs & derivatives; Headache. Facial pains. Syncopes. Epilepsia. Intracranial hypertension. Brain oedema. Cerebral palsy; Humans; Infant; Isoxazoles - adverse effects; Ketogenic diet; Kidney stones; Male; Medical sciences; Nervous system (semeiology, syndromes); Neurology; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Retrospective Studies; Risk Factors; Topiramate; Urolithiasis - chemically induced; Zonisamide; Topiramate; Epilepsy; Ketogenic diet; Zonisamide; Kidney stones; Nervous system diseases; Concurrent; Anticonvulsant; Kidney; Cerebral disorder; Treatment; Urinary system; Sulfonamides; Central nervous system disease; Lithiasis; Benzisoxazole derivatives
• ISSN: 0920-1211; 1872-6844
• DOI: 10.1016/j.eplepsyres.2010.04.005

Summary Children with refractory epilepsy who are co-treated with the ketogenic diet (KD) and carbonic anhydrase inhibitor (CA-I) anti-epileptic medications including topiramate (TPM) and zonisamide (ZNS) are at risk for urolithiasis. Retrospective chart review of all children treated with ketogenic therapy at our institution was performed in order to estimate the minimal risk of developing signs or symptoms of stone disease. Children ( N = 93) were classified into groups according to KD +/− CA-I co-therapy. Fourteen patients had occult hematuria or worse, including 6 with radiologically confirmed stones. Three of 6 calculi developed in the KD + ZNS group of 17 patients who were co-treated for a cumulative total of 97 months (3.1 stones per 100 patient months). One confirmed stone was in the KD + TPM group of 22 children who were co-treated for a cumulative total of 263 months (0.4 stones per 100 patient months). All six patients had at least three of five biochemical risk factors including metabolic acidosis, concentrated urine, acid urine, hypercalciuria and hypocitraturia. Standard of care interventions to minimize hypercalciuria, crystalluria and stone formation used routinely by pediatric nephrologists should also be prescribed by neurologists treating patients with combination anti-epileptic therapy. Non-fasting KD initiation, fluid liberalization, potassium citrate prophylaxis as well as regular laboratory surveillance are indicated in this high risk population.