2019 Volume 31 Issue 1 Pages 66-73
A 57-year-old woman with a 15-year history of post surgically treated right temporal lobe epilepsy and subsequent chronic psychosis controlled on carbamazepine (CBZ), valproate (VPA), and bromperidol was seen for a regular medical check-up. CBZ was increased in dosage 7 months prior to admission. Laboratory tests taken after an 11-month interval showed an increase in serum creatinine (1.2 mg/dl) compared to baseline concentration (0.6 mg/dl), without any systemic manifestations such as fever and rash. CBZ and VPA were discontinued in suspect of drug-induced renal impairment, and lamotrigine was initiated for replacement. Histological confirmation of acute interstitial nephritis (AIN) was made by renal biopsy. Elevated levels of indicator proteins for renal tubular dysfunction decreased after discontinuation of CBZ, albeit with kidney injury remaining thereafter. Recently, complications among those receiving long-term therapy by conventional antiepileptic drugs are becoming an increasing concern, and it is of interest to psychiatrists in the general hospitals to manage such potential harm. Herein we report a case of drug-induced AIN, with CBZ being the probable cause. As AIN presents with non-specific symptoms, delays in recognition are common and may result in serious kidney injury. Therefore, even among patients with a stable course, regular laboratory evaluations are warranted to recognize any early organ involvement when changes in medication are made.
