Which of the following is NOT an adverse effect associated with imatinib or dasatinib?

The option indicating hemorrhagic cystitis is correct as it is not typically associated with imatinib or dasatinib. These medications are targeted therapies primarily used to treat certain types of leukemia, particularly chronic myeloid leukemia (CML), and are known for a distinct side effect profile.

Fluid retention is a known adverse effect of both imatinib and dasatinib. It can manifest as edema and is particularly notable in patients receiving these therapies, where it may lead to symptoms like swelling in the limbs or abdominal distention.

QT prolongation is another recognized side effect, especially with dasatinib, which has been documented to affect the heart rhythm and necessitates monitoring of the ECG in patients.

Gastrointestinal (GI) upset, such as nausea, vomiting, and diarrhea, is also common among patients taking these medications. GI symptoms can significantly impact the quality of life and are frequently reported in clinical settings.

In contrast, hemorrhagic cystitis is classically associated with certain chemotherapeutic agents, such as cyclophosphamide, but is not a characteristic adverse effect linked to imatinib or dasatinib. Therefore, it stands apart from the other options listed, making it the correct choice for this question.