Lack of penetration of amikacin into saliva of tuberculosis patients

In the 2016 update of the World Health Organization treatment guideline for drug-resistant tuberculosis (TB), a shorter multidrug-resistant TB regimen was proposed because of its higher treatment outcomes [1]. However, therapeutic drug monitoring (TDM) is an excellent method to improve clinical outcomes as well and its practice is on the rise [2]. A well-known side-effect of group B injectable anti-TB drugs (e.g. amikacin) is ototoxicity [3]. TDM could also be a solution to minimise side-effects by lowering the drug exposure [4]. In the study by van Altena et al. [5], TDM was practised using the ratio of peak concentration (Cmax) to minimal inhibitory concentration (MIC) and this resulted in a reduction in patients with hearing loss. Saliva is considered as an alternative matrix for TDM because it is easy, noninvasive and more patient friendly to sample [6]. Studies found a limited penetration of gentamycin and tobramycin into saliva [7], while detectable levels of amikacin in saliva of neonates were reported [8]. Given the low penetration of aminoglycosides into saliva and interest in Cmax for TDM of amikacin, our objective was to study whether the salivary Cmax of amikacin is measurable and useful in salivary TDM.Salivary CmaxTDM of amikacin was not feasible in TB treatment due to the very low penetration into saliva http://ow.ly/d6v230h0bW