Abstract
Antibiotics like amikacin and polymyxin B play an important role in treating infections caused by multidrug-resistant Gram-negative bacteria. However, both drugs can lead to neurotoxic effects, which may worsen if they are administered sequentially or concurrently. This case report discusses a 19-year-old female patient diagnosed with aplastic anemia. She was admitted with symptoms of fever, fatigue, and gum bleeding. Initially, she was treated with amikacin. She had a persistent fever, for which the antibiotic was escalated to Polymyxin B in suspicion of a hospital-acquired infection. Shortly after receiving the first dose of Polymyxin B, the patient experienced acute neurotoxic symptoms, including blurred vision, vomiting, tingling in the cheeks, and headache. These symptoms rapidly improved with supportive care, and no further symptoms were noted when she continued with a maintenance dose of Polymyxin B. The timing of the antibiotic use and the onset of symptoms suggest a combined neurotoxic effect. The presence of amikacin may have induced the sensitivity of nerve tissues, lowering the threshold for neurotoxicity from polymyxin B. Failing to monitor drug levels and not adhering to standard dosing schedules may have contributed to this issue. This case highlights the risk of increased neurotoxicity when aminoglycosides and polymyxins are administered subsequently. Furthermore, it emphasizes the need for proper dosing and consideration of monitoring drug levels to reduce neurological complications.

Key words: Amikacin, Polymyxin B, Drug - Drug Interaction, Neurotoxicity, Severe