for people with neutropenia and fever. Available forms Amikacin may be administered once or twice a day and is usually given by the intravenous or intramuscular route, though it can be given via nebulization. There is no oral form available, as amikacin is not absorbed orally. In people with kidney failure, dosage must be adjusted according to the creatinine clearance, usually by reducing the dosing frequency. In people with a CNS infection such as meningitis, amikacin can be given intrathecally (by direct injection into the spine) or intraventricularly (by injection into the ventricles of brain). An liposome inhalation suspension is also available and approved to treat Mycobacterium avium complex (MAC) in the United States. The application for Arikayce was withdrawn in the European Union because the Committee for Medicinal Products for Human Use (CHMP) was of the opinion that the benefits of Arikayce did not outweigh its risks. Special populations Amikacin should be used in smaller doses in the elderly, who often have age-related decreases in kidney function, and children, whose kidneys are not fully developed yet. It is considered pregnancy category D in both the United States and Australia, meaning they have a probability of harming the fetus. Around 16% of amikacin crosses the placenta; while the half-life of amikacin in the mother is 2 hours, it is 3.7 hours in the fetus. A pregnant woman taking amikacin with another aminoglycoside has a possibility of causing congenital deafness in her child. While it is known to cross the placenta, amikacin is only partially secreted in breast milk. In general, amikacin should be avoided in infants. Infants also tend to have a larger volume of distribution due to their higher concentration of extracellular fluid, where aminoglycosides reside. The elderly tend to have amikacin stay longer in their system; while the average clearance of amikacin in a 20-year-old is 6 L/hr, it is 3 L/hr in an 80-year-old. Clearance is even higher in people with cystic fibrosis. In people with muscular disorders such as myasthenia gravis or Parkinson's disease, amikacin's paralytic effect on neuromuscular junctions can worsen muscle weakness. Adverse effects Side-effects of amikacin are similar to those of other aminoglycosides. Kidney damage and ototoxicity (which can lead to hearing loss) are the most important effects, occurring in 1–10% of users. The nephro- and ototoxicity are thought to be due to aminoglycosides' tendency to accumulate in the kidneys and inner ear.