Reversible audiometric threshold changes in children with uncomplicated malaria

Ototoxic hearing loss from antimalarials: A systematic narrative review

BACKGROUND

Drugs used in curative and prophylactic antimalarial treatment may be ototoxic and lead to permanent hearing loss, but there is no consensus regarding prevalence and permanence of ototoxic hearing loss caused by antimalarials. The purpose of this systematic narrative review was to synthesize current evidence on antimalarial ototoxicity in human populations.

METHOD

Studies published between 2005 and 2018 that reported prevalence of post-treatment hearing loss in individuals treated for malaria were included.

RESULTS

Twenty-two studies including data from 21 countries were included. Primary themes of the included studies were to evaluate drug safety and/or efficacy (n = 13) or ototoxic effects of drugs (n = 9). Hearing data were measured objectively in 9 studies. Five studies focused on quinine (or derivates), 10 focused on artemisinin combination therapies, and 7 considered multiple drug combinations. There is a paucity of evidence that thoroughly reports potentially permanent ototoxic effects of antimalarials.

CONCLUSIONS

Antimalarial drugs may be ototoxic in some cases. More research in human populations is needed to describe ototoxicity of current antimalarials and of future drugs that will be used/developed in response to antimalarial resistance. It is recommended that randomized trials evaluating drug safety objectively measure and report ototoxic hearing loss as an adverse event.

Investigation of ototoxicity of artesunate as add-on therapy in patients with metastatic or locally advanced breast cancer: new audiological results from a prospective, open, uncontrolled, monocentric phase I study

PURPOSE

Artesunate (ART) has been used for a long time in the treatment of Plasmodium falciparum malaria and has been considered safe. The present phase I study aimed to determine the daily dose of ART that is well tolerated as add-on therapy in patients with breast cancer for 4 weeks of therapy. Ototoxicity could be a potential safety concern in settings different from malaria. Therefore, comprehensive audiological assessment was essential.

METHODS

The ARTIC M33/2 study was a prospective, open, uncontrolled, monocentric phase I dose-escalation study to evaluate the safety and tolerability of ART in patients with advanced breast cancer. Patients received either 100, 150 or 200 mg oral ART daily for a test phase of 4 weeks as add-on therapy to their ongoing oncological treatment. For the investigation of the safety of ART for hearing, an audiological assessment was performed with each patient before the intake of ART and after 4 weeks of therapy.

RESULTS

Twenty-three female patients were included in the study. During the test phase, four patients had adverse events (AEs) of the auditory system possibly related to the intake of ART. However, none of these AEs was classified as severe AE (SAE) and did not require treatment interruption. Four patients had AEs concerning the vestibular system (vertigo) during the test phase, one of which was classified as SAE. However, the SAE was fully reversible after discontinuation of ART.

CONCLUSION

None of the audiological results after 4 weeks of therapy with ART showed any dose-limiting auditory toxicity. However, audiological monitoring in further clinical studies with prolonged use of oral ART in doses up to 200 mg daily is warranted. The ARTIC M33/2 study is registered at eudract.ema.europa.eu with the Number 2007-004432-23 and at clinicaltrials.gov with the Number NCT00764036.

Severe malaria in children leads to a significant impairment of transitory otoacoustic emissions--a prospective multicenter cohort study

BACKGROUND

Severe malaria may influence inner ear function, although this possibility has not been examined prospectively. In a retrospective analysis, hearing impairment was found in 9 of 23 patients with cerebral malaria. An objective method to quickly evaluate the function of the inner ear are the otoacoustic emissions. Negative transient otoacoustic emissions are associated with a threshold shift of 20 dB and above.

METHODS

This prospective multicenter study analyses otoacoustic emissions in patients with severe malaria up to the age of 10 years. In three study sites (Ghana, Gabon, Kenya) 144 patients with severe malaria and 108 control children were included. All malaria patients were treated with parental artesunate.

RESULTS

In the control group, 92.6 % (n = 108, 95 % confidence interval 86.19-6.2 %) passed otoacoustic emission screening. In malaria patients, 58.5 % (n = 94, malaria vs controls p < 0.001, 95 % confidence interval 48.4-67.9 %) passed otoacoustic emission screening at the baseline measurement. The value increased to 65.2 % (n = 66, p < 0.001, 95 % confidence interval 53.1-75.5 %) at follow up 14-28 days after diagnosis of malaria. The study population was divided into severe non-cerebral malaria and severe malaria with neurological symptoms (cerebral malaria). Whereas otoacoustic emissions in severe malaria improved to a passing percentage of 72.9 % (n = 48, 95 % confidence interval 59-83.4 %) at follow-up, the patients with cerebral malaria showed a drop in the passing percentage to 33 % (n = 18) 3-7 days after diagnosis. This shows a significant impairment in the cerebral malaria group (p = 0.012 at days 3-7, 95 % confidence interval 16.3-56.3 %; p = 0.031 at day 14-28, 95 % confidence interval 24.5-66.3 %).

CONCLUSION

The presented data show that 40 % of children have involvement of the inner ear early in severe malaria. In children, audiological screening after severe malaria infection is not currently recommended, but is worth investigating in larger studies.