Effect of Cyclosporin A on Hearing Status in Children with Difficult to Treat Idiopathic Nephrotic Syndrome

Background: Cyclosporin A (CsA) is an important drug regimen for difficult to treat nephrotic syndrome (NS) with few information known about its ototoxicity.

Aims: Assessment the hearing status in children with difficult to treat idiopathic NS on CsA treatment.

Material and Methods: This prospective cohort study included 2 groups: Group I: 15 children with steroid sensitive idiopathic nephrotic syndrome on steroids only as a line of treatment was used as comparing group to group II which included 15 children recently diagnosed difficult to treat NS starting CsA as steroids sparing drug, hearing functions were assessed using standard, high-frequency audiometry and transient otoacoustic emissions (TOAEs) at base line for both groups and after 6 months of CsA treatment for group II.

Results: There was significant elevation of hearing threshold in extended high frequency (> 8 KHz) (subclinical hearing loss) after six months of CsA. There was positive correlation between Cyclosporin A trough level and elevated hearing threshold in pure tone audiometry and extended high frequency (> 8 KHz). There was insignificant difference between groups according to TOAEs. There was statistically significant positive correlation between extended high frequency range and serum trough CsA level in group II.

Conclusions: CsA is a potential cause of hearing impairment in children with difficult to treat NS so all patients on CsA need routine audiological assessment especially with high serum CsA level and long duration.