Which adverse effect of gentamicin should the nurse report to the provider?

Gentamicin is an aminoglycoside antibiotic that is notable for its potential to cause ototoxicity, which can manifest as tinnitus, or ringing in the ears. This adverse effect is particularly significant because it may signal damage to the auditory system, which can lead to permanent hearing loss if not addressed promptly. Therefore, reporting tinnitus to the provider is critical for evaluating the patient's condition and potentially adjusting the medication regimen or implementing further monitoring to prevent irreversible effects.

In contrast, while constipation, hypoglycemia, and joint pain may present their own concerns, they are not typically recognized as common or significant adverse effects associated with gentamicin therapy. Thus, they do not carry the same urgency for reporting in the context of gentamicin use.