Which of the following routes is least common for administering aminoglycosides?

The subcutaneous route is considered the least common for administering aminoglycosides due to the pharmacokinetic properties of these medications. Aminoglycosides, such as gentamicin and amikacin, are primarily utilized for their potent antibacterial effects against serious infections, particularly those caused by gram-negative bacteria. These drugs are typically not absorbed well through the gastrointestinal tract, making oral administration ineffective for therapeutic purposes.

In contrast, intravenous and intramuscular routes are preferred because they ensure rapid and reliable absorption of the drug into systemic circulation, allowing for effective treatment of severe infections. Subcutaneous administration would not only lead to variable absorption but could also result in inadequate levels of the medication, which is critical when managing life-threatening infections. Thus, the subcutaneous route is rarely used for aminoglycosides due to these considerations in efficacy and absorption.