Chemotherapy Side Effects & Nursing

Chemotherapy kills cancer cells — but it also destroys every rapidly dividing healthy cell in its path. Knowing which cells die first tells you exactly which side effects to expect and when.

Chemotherapy targets rapidly dividing cells indiscriminately, so the body's fastest-dividing healthy tissues take the hardest hit: bone marrow, GI mucosa, and hair follicles. Bone marrow suppression (myelosuppression) is the most dangerous effect. The nadir — the lowest point of blood cell counts — typically occurs 7–14 days after treatment. During the nadir, the client is most vulnerable to infection, bleeding, and severe fatigue. Neutropenia (ANC below 1,500/mm³) requires neutropenic precautions: no fresh flowers or raw fruits/vegetables, private room, strict hand hygiene, no rectal temperatures or suppositories, and no IM injections. Thrombocytopenia (platelets below 50,000/mm³) means bleeding precautions: soft toothbrush, electric razor, avoid aspirin and NSAIDs. Stomatitis and mucositis develop because GI epithelial cells turn over every 3–5 days; assess the oral cavity daily and use gentle mouth care with soft-bristle brushes and saline or sodium bicarbonate rinses — avoid alcohol-based mouthwash. Nausea and vomiting are managed with antiemetics given 30–60 minutes before chemotherapy, not after symptoms start. Alopecia is psychologically significant but not medically dangerous; prepare the client beforehand. Extravasation of vesicant agents (doxorubicin, mechlorethamine) requires immediate action: stop the infusion, aspirate residual drug, and follow facility-specific antidote protocol.

Key Distinctions

Don't confuse nadir (the lowest WBC count at 7–14 days) with the day of infusion — the patient looks fine on chemo day but is most at risk one to two weeks later. Students mix up neutropenic precautions (infection prevention) with bleeding precautions (thrombocytopenia) — they overlap but have different triggers. Extravasation (vesicant leaking into tissue) is not the same as infiltration of non-vesicant fluid; vesicants cause tissue necrosis and require antidotes.

Clinical Pearl

Think 'nadir = naked defense.' At 7–14 days post-chemo, the immune system is at its lowest — a low-grade fever of 100.4°F (38°C) is an emergency, not a wait-and-see.