Table 1 Shows a summary of included studies

Riga et al. 2013

Greece

RCT

20 out of 24 candidates for cisplatin-based chemotherapy completed the trial.

Transtympanic infusions of diluted solution of 10% N-acetylcysteine by adding Ringer Lactate

none

1 month after the end of cisplatin chemotherapy session. As a session, it was considered 2 to 3 cisplatin chemotherapy cycles according to the therapeutic protocol.

Hearing acuity was evaluated before each cycle with pure tone audiometry.

Transtympanic injections of N-acetylcysteine may be a safe and effective way to prevent cisplatin-induced ototoxicity especially at high frequencies.

Yoo et al. 2014

Canada

RCT

11 out of 13 patients receiving cisplatin chemotherapy for head and neck cancer completed the trial.

Transtympanic 2% L-NAC

none

at 1 to 2 months following chemotherapy.

the difference in the loss of pure tone averages (PTA) at 2, 4, and 8 kHz

No overall significant benefit was demonstrated, except for two patients in which transtympanic L-NAC was associated with significantly better hearing.

Better delivery methods may improve the efficacy of this treatment.

Sarafraz et al. 2018

Shahid Sadoughi University of Medical Sciences in Yazd, Iran

2016–2017

RCT

57 out of 60 cisplatin-treated patients completed the trial.

Transtympanic injection of N-acetylcysteine (10%)

dexamethasone

before each cycle and six months later.

Hearing acuity was evaluated with pure tone audiometry (PTA)

Transtympanic injections of N-acetylcysteine as a safe and inexpensive antioxidant agent seem to be an effective otoprotective strategy for the prevention of cisplatin-induced ototoxicity and for increasing the quality of life -especially in children-, which is evident at high frequencies (8000 Hz)