Fernandez-Juarez G, et al. - In this retrospective study, researchers intended to gain clarity regarding the timing of initiation, effectiveness, safety, and duration of corticosteroid treatment in drug-induced acute interstitial nephritis. Participants were 182 patients with biopsy-proven drug-induced acute interstitial nephritis from 13 Spanish centers. The definition of exposure was the length of corticosteroid treatment. They mainly assessed the level of serum creatinine at month 6, with respect to baseline values. In drug-induced acute interstitial nephritis, high-dose corticosteroid treatment for 3 weeks or prolonged treatment for >8 weeks were not found to be related to greater kidney function recovery. Worse recovery of kidney function was seen with a delay in the initiation of corticosteroids.