known or not) when starting antibiotics and other medications that are renally excreted GENITOURINARY COMPLICATIONS OF CANCER TREATMENT The most common form of bladder injury in cancer patients is hemorrhagic cystitis, a potential complication of exposure to cyclophosphamide or ifosfamide Prevention of drug-induced hematuria usually includes hydration, frequent voiding, and administration of mesna (2-mercaptoethane sulfonate sodium), a drug that binds the toxic metabolite Manifestations include dysuria, suprapubic pain, and microscopic or gross hematuria with onset within 24 hours of drug administration Other causes of toxicity to the GU tract include infection, bladder radiation, tumor resection, or ongoing presence of tumor in the GU tract If a patient is complaining of bladder-related symptoms or the urinalysis shows evidence of hematuria, the oncology-specific history should be reviewed to help develop an appropriate differential diagnosis in addition to the usual causes (such as infection) that would be considered in a patient without cancer Initial management should include initiation of one and one-half times to twice maintenance hydration and frequent voiding Laboratory evaluation should include a urinalysis, CBC to look for anemia or thrombocytopenia, and coagulation studies Any contribution from coagulopathy and/or thrombocytopenia should be corrected If severe bleeding or bladder outlet obstruction from clots occurs, a urologist should be consulted A bladder catheter large enough to be used for irrigation should be placed and bladder washing initiated Packed red blood cell transfusion may be needed In very rare cases, bleeding can be life threatening and bladder sclerosis is indicated Mesna has no utility once the offending drug has cleared from the system Pain management with oxybutynin chloride and narcotics should be initiated as needed SKIN COMPLICATIONS OF CANCER TREATMENT Various cancer treatments are known to have cutaneous toxicities Radiation induces dermatitis in the treatment field that can range from mild to severe based on the total dose and any concurrent radiation sensitizers The presentation may vary from a mild erythroderma, similar to sunburn, to severe desquamation in the treatment field Any topical treatment must be prescribed in conjunction with the treating radiation oncologist because certain topical agents may increase the radiation dose to the skin Drug rashes are very common in oncology patients Because patients tend to be on many drugs at one time, it may be difficult to identify the specific culprit Management of a drug reaction is not unique in oncology patients However, consultation with the oncologist may be needed to discuss if alternate treatment is needed