Dose-limiting toxicity of anticancer chemotherapy:
1. Gastrointestinal toxicity
a. It is common and can manifest as nausea, vomiting, diarrhea and constipation. Sometimes, hemorrhage in the gut can also occur.
b. 5-HT3 antagonists are the drugs of choice for chemotherapy induced vomiting.
c. Granisetron is available in the patch that can be put 24 hours before chemotherapy and can be left for 1 week afterwards.
d. Aprepitant, a neurokinin receptor antagonist can also be used in refractory vomiting.
a. Depression of bone marrow results in granulocytopenia, agranulocytosis, thrombocytopenic, aplastic anaemia. This is the most serious toxicity, often limits the does that can be employed. Infections and bleeding are the usual complications.
b. It occurs commonly with Busulphan, hydroxyurea, nitrosoureas, platinum compounds, cyclophosphamide and doxorubicin.
c. Drugs like streptozotocin, bleomycin and vincristine produce minimal bone marrow depression.
d. Bone marrow suppression of various degrees can occur. All cell lines can be affected and allogenic bone marrow transplant may be needed.
a. It is the most common toxic feature of anthracycline antibiotics. For example, dose dependent cardiac damage occurs with doxorubicin.
b. It is more common when dose is more than 550 mg/M2 and can be free radical mediated.
c. Treatment involves a free radical scavenger (dexrozoxane) (Dhikav V, Drugs of Choice’ 4thedition, 2010).
d. Though, there is evidence that cardiac damage could be dose limiting in case of anthracycline, but mostly, it is depression of bone marrow that is often dose limiting. Therefore, the correct answer should be B.
e. Damage to the skin cells can lead to proliferative changes in the nearby cells leading to changes in skin, nails, hairs and mucous membranes. Photosensitivity, petechiae, nail changes, exfoliation, erythema are usual changes.