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Dr. Jaume Almirall, Hospital de Sabadell, Consorci Hospitalari del Parc Taulí, Nephrology Unit, Ap., C. 196, E-08208 Sabadell, Barcelona (Spain) Dear Sir, Garbamazepine is mostly used in partial seizures with complex symptoms. The most frequent adverse reactions are dizziness, drowsiness, unsteadiness, nausea and vomiting. We may also observe aplastic anemia, leukopenia, agranulocytosis, abnormal liver function tests and dermatological signs of hypersensitivity. The kidney is rarely involved, water retention due to inappropriate secretion of anti-diuretic hormone being the most frequent adverse reaction. It has also been reported to induce tubulointerstitial nephritis in the context of an allergic reaction [1-5]. Tubular necrosis caused by carbamazepine has been reported [6]. We observed a new case of tubular necrosis as a toxic reaction secondary to over-dosage. A 48-year-old man was admitted to hospital because of dizziness and unsteadiness. Five years before he had started carbamazepine (200^100 mg) therapy because of complex partial epilepsy. He had had no seizures for the last 2 years. He had no past history of renal disease. Routine blood examination and renal function tests were normal. Two weeks before admission he complained of unsteadiness which was thought to be peripheric dizziness. He returned to the hospital complaining of dizziness, nausea and vomiting. Physical examination on admission revealed a conscious man, well hy-drated, temperature 36.5 °C, pulse 84, and blood pressure 140/80. He had horizontal nystagmus with no other findings. On admission hemoglobin was 11.9 g/l00 ml, white cell count 8,600/mm3 with no eosinophilia; blood urea was 110 mg/dl (39,3 mmol/l) and serum creatinine 8.1 mg/dl (715 μmol/l); Na+ 134 mEq/1, K+ 3.9 mEq/1, HCO3 29 mEq/1. Urine showed 6-8 red cells, abundant granular casts, no white cells; protein 0.79 g/l, and Na+ < 10 mmol/l. The urinary output was 1,200 c 3. The carbamazepine level was 14.7 μg/ml (reference values 8-12 μg/ml). After withdrawal of carbamazepine the patient improved rapidly on consevative management of the renal failure. The dizziness and nystagmus disappeared within 24 h. During the next week urea fell to 74 mg/dl (26.3 mmol/l) and creatinine to 1.4 mg/dl (124 μmol/l). Confirmative analysis by renal biopsy was not done because of the fast recovery of the patient. Twenty-one days later he had normal renal function, creatinine was 1 mg/dl (89