A nurse is collecting data from a client who has pyelonephritis and is receiving gentamicin via IV infusion. Which of the following manifestations should the nurse identify as an adverse effect of the treatment?

A. New onset of hearing loss. Gentamicin is an aminoglycoside antibiotic known for its ototoxic effects, which can lead to irreversible hearing loss or vestibular dysfunction. The drug damages the hair cells in the inner ear, resulting in symptoms like tinnitus, dizziness, or difficulty hearing. Clients receiving gentamicin should be closely monitored for auditory changes, as early detection can help prevent worsening damage. B. Constipation. Gentamicin does not typically affect gastrointestinal motility, making constipation an unlikely adverse effect. It primarily causes nephrotoxicity and ototoxicity, with its main targets being the kidneys and inner ear. Gastrointestinal side effects are rare and usually limited to nausea or mild discomfort rather than significant bowel irregularities. C. Slurred speech. While aminoglycosides can cause neuromuscular blockade in rare cases, slurred speech is not a common adverse effect. More frequently, gentamicin affects the vestibular system, leading to balance disturbances or dizziness rather than impairing speech function. If neuromuscular symptoms develop, the medication should be reassessed to prevent severe complications. D. Hypotension. Gentamicin does not directly cause hypotension as a primary side effect. Its adverse effects are more commonly associated with kidney damage, ototoxicity, and, in rare cases, neuromuscular paralysis. If a client on gentamicin experiences hypotension, other underlying causes such as sepsis or volume depletion should be considered.