Assessment of the Incidence, Pattern, and Severity of Chemotherapy-Induced Adverse Drug Reactions in Cancer Patients

Chemotherapy is a major component of cancer treatment but is frequently associated with adverse drug reactions (ADRs) that negatively affect patient well-being, treatment adherence, and clinical outcomes. Nausea and vomiting are among the most common chemotherapy-induced adverse effects, particularly with highly emetogenic chemotherapy. Evidence summarized in this review indicates that ADRs commonly involve the hematological, gastrointestinal and nervous systems, with neutropenia, anemia, mucositis, nausea/vomiting and peripheral neuropathy among the major toxicities. A comparative study involving 162 women with ovarian cancer receiving cisplatin-based chemotherapy demonstrated that the duration of nausea was an important determinant of well-being, independent of nausea intensity. Chemotherapy ADRs may be predictable and dose-dependent or idiosyncratic and immune-mediated. Important risk factors include patient characteristics, comorbidities, treatment intensity, combination therapy and pharmacogenetic variation, including DPYD and UGT1A1 variants. Assessment incorporates clinical and laboratory monitoring, causality tools such as Naranjo and WHO-UMC, and severity grading using CTCAE. Management includes antiemetic prophylaxis, growth-factor support, hydration, dose modification and pharmacogenomic-guided interventions. Systematic pharmacovigilance and proactive toxicity monitoring are essential for reducing chemotherapy-related morbidity and improving patient safety.