Netilmicin shares many characteristics with gentamicin and tobramycin. However, the addition of an ethyl group to the 1-amino position of the 2-deoxystreptamine ring (ring II, Figure 45–2) sterically protects the netilmicin molecule from enzymatic degradation at the 3-amino (ring II) and 2-hydroxyl (ring III) positions. Consequently, netilmicin may be active against some gentamicin-resistant and tobramycin-resistant bacteria.
The dosage (5–7 mg/kg/d) and the routes of administration are the same as for gentamicin. Netilmicin is largely interchangeable with gentamicin or tobramycin but is no longer available in the United States.