Researchers in the Netherlands have found that halving the dosage of second-line tuberculosis treatments can be effective without the unpleasant side effects, reports

The aminoglycosides amikacin and kanamycin — two second-line injectable drugs for the treatment of multidrug-resistant (MDR)-TB — have both been associated with “profound and permanent” toxicity, with 8% to 37% of patients experiencing hearing loss and nephrotoxicity after taking them for any period of time, according to researchers. Prolonged treatment with the drugs and at higher doses may compound these problems.

At their TB Center in the Netherlands, Alffenaar and colleagues monitor concentrations of aminoglycosides in patients’ blood, making adjustments based on a prespecified maximum concentration to mean inhibitory concentration ratio. This allows them to maintain the efficacy of a patient’s regimen while reducing its toxicity at lower doses. In the study, drug susceptibility testing was conducted for all patients.

“If the bacteria are more susceptible to the antibiotic than normal, we can use a lower dose,” Alffenaar said in a press release.