topiramate and Hypercalciuria

Topiramate is an approved drug to treat seizures, but its indications have been extended to other diseases of the nervous system and as an adjuvant to chronic pain. We present four cases of topiramate-induced nephrolithiasis from 2006-2012 in women whose treatment was prescribed for pain control and as a mood stabilizer at doses of 250-300 mg/day. In two cases, the lithiasis was caused by calcium phosphate (patite) and in the other two cases by oxalate and calcium phosphate. The most common metabolic alteration was an alkaline pH, followed by hypocitraturia. The drug was discontinued in two patient; it was reduced in one and was maintained in the fourth. An increase in fluid and potassium citrate intake was prescribed. In patients starting treatment with topiramate, an adequate control and prevention of nephrolithiasis should be performed due to the risk of mixed tubular acidosis and hypocitraturia. to the risk of mixed tubular acidosis and hypocitraturia.

Topics: Adult; Aged; Analgesics; Calcium Oxalate; Calcium Phosphates; Chronic Pain; Citric Acid; Female; Fructose; Humans; Hypercalciuria; Kidney Calculi; Middle Aged; Nephrolithiasis; Personality Disorders; Potassium Citrate; Psychotropic Drugs; Topiramate

Topiramate (TPM), an anti-epileptic drug with >4 million users, increases renal stones in adults. We screened outpatient TPM-treated children without history of stones to estimate the prevalence of renal stones and to characterize urine stone-risk profiles.. Children taking TPM ≥1 month underwent an interview, renal ultrasound, and spot urine testing in this prospective study. Normal spot urine values were defined as: calcium/creatinine ratio ≤0.20 mg/mg (>12 months) or ≤0.60 mg/mg (≤12 months), citrate/creatinine ratio >0.50 mg/mg, and pH ≤ 6.7.. Of 41 patients with average age of 9.2 years (range 0.5-18.7), mean TPM dose of 8.0 mg/kg/day (range 1.4-23.6), and mean treatment duration of 27 months (range 1-112), two (4.9%) had renal stones. The majority of children taking TPM had lithogenic abnormalities on spot urine testing, including 21 (51%) with hypercalciuria, 38 (93%) with hypocitraturia, and 28 (68%) with pH ≥ 6.7. Hypercalciuria and hypocitraturia were independent of TPM dose and duration; urine pH increased with dose. 24-h urine parameters improved in 1 stone-former once TPM was weaned.. Asymptomatic stones were found in 2/41 (4.8%) children taking TPM. Risk factors for stones were present in the spot urine of most children, including hypocitraturia (93%) and hypercalciuria (51%), independent of TPM dose and duration. High urine pH, found in 68%, correlated with TPM dose. Pediatric specialists should be aware of increased risks for stones, hypercalciuria, hypocitraturia, and alkaline urine in children taking TPM.

Topics: Adolescent; Alkalies; Anticonvulsants; Calcium; Child; Child, Preschool; Citric Acid; Creatinine; Epilepsy; Female; Fructose; Humans; Hypercalciuria; Infant; Kidney Calculi; Male; Prevalence; Prospective Studies; Risk Factors; Topiramate