A nurse on an oncology unit is preparing to administer doxorubicin to a client who has breast cancer. Prior to beginning the infusion, the nurse verifies the client's current cumulative lifetime dose of the medication. For which of the following reasons is this verification necessary?

The correct answer is C: An excess amount of doxorubicin can lead to cardiomyopathy. Doxorubicin is known to be cardiotoxic, with the risk of developing cardiomyopathy increasing with higher cumulative doses. This verification is necessary to prevent potential cardiac complications in the client. Choice A is incorrect because exceeding the dose limit would not directly cause extravasation. Choice B is incorrect as red tinged urine and sweat are not specific to exceeding the cumulative dose limit of doxorubicin. Choice D is incorrect as myelosuppression is a known side effect of doxorubicin but is not directly related to exceeding the cumulative dose limit.