Incompatibility: Extemporaneous admixtures of beta-lactam antibacterials and aminoglycosides may result in substantial mutual inactivation. If these groups of antibacterials are administered concurrently, they should be administered in separate sites at least 1 hour apart. Do not mix them in the same intravenous bag, bottle, or tubing.
When aminoglycosides and penicillins are administered separately by different routes, a reduction in aminoglycosides serum concentration may occur. Usually this is clinically significant only in patients with severely impaired renal function when the excretion of both medications is delayed.