Antibiotics are therapy to treat diseases caused by bacterial infection. Infectionus diseases are one of the biggest diseases in Indonesia, including pneumonia (Kemnkes, 2018). The high prevalence of infectious diseases leads to more and more irrational use of antibiotics and the potensial for antibiotic resistance ( A. Rahimi, et.al., 2018). Amikacin and gentamicin are aminoglycoside antibiotics used to treat pneumonia. These antibiotics are included in the category of narrow therapeutics index drugs, so it is necessary to monitor drug levels in the blood to prevent toxicity and resistance and increase the success of therapy.

This study aims to determine the pharmacokinetics of amikacin and gentamicin drug levels and calculate the dose adjustment to fit within the drug therapy range. This research was conducted with an observasional design. Data collection through Medical Record data at RSUD Margono Soekardjo Purwokerto for the period January-Desember 2020.

The results of this study show that of the 37 respondents who received amikacin as many as 8 respondents (21,62%) and 29 respondents (78,38%) who received gentamicin. All respondents who received amikacin did not have a suitable ratio of Cmax/MIC > 8 and Cmax > 64 mg/L, so it was necessary to adjust the dose to achieve optimal levels. The optimal level of amikacin is stated to be achieved whwn the ratio of Cmax/MIC > 8 and Cmax > 64 mg/L will optimally produce a Minimum Inhibitor Concentration (MIC) of 8 mg/L (Aliska, et.al., 2017). All respondents who received gentamicin had drugs levels that were within the therapeutic rage (0,5-10 mg/L) so no need for dose adjustment.

Based on the results of this study, it can be concluded that monitoring of antibiotic levels with a narrow therapeutic index needs to be a carried out to optimize antibiotic levels so that they can produce Minimum Inhibitor Concentration (MIC) and reach therapeutic range levels to increase therapeutic success and prevent antibiotic resistance and toxicity

Keywords : Aminoglycoside, Minimum Inhibitor Concentration, Pharmakokinetic