Chemotherapy

A single splash of cyclophosphamide on ungloved skin can cause mutagenic exposure — and the nurse, not the patient, becomes the victim. Safe handling isn't optional; it's self-preservation.

Chemotherapy agents are hazardous drugs classified by NIOSH — they can cause reproductive harm, cancer, and organ damage in healthcare workers through skin absorption, inhalation, or accidental ingestion. Personal protective equipment (PPE) for handling includes chemotherapy-rated double gloving, a closed-front disposable gown, eye protection, and a respirator when aerosolization risk exists. All preparation occurs in a biological safety cabinet (BSC) with vertical laminar airflow — never at the bedside or under a horizontal hood. Administration requires a closed-system transfer device (CSTD) to prevent drug escape. IV tubing must be primed with non-drug solution before attaching the chemotherapy bag. Spill kits must be immediately accessible on the unit; spills are cleaned inward to outward to avoid spreading. All contaminated materials — gowns, gloves, tubing, empty bags — go in yellow chemotherapy waste containers, not regular biohazard (red bag) trash. Body fluids of patients receiving chemo are considered hazardous for 48 hours post-administration; nurses and caregivers handling urine, stool, emesis, or linens within this window must wear chemotherapy-rated gloves. Pregnant nurses should not handle or administer chemotherapy under any circumstance.

Key Distinctions

Don't confuse standard biohazard waste (red bag) with chemotherapy waste (yellow bag) — mixing them is a regulatory and safety violation. Students assume regular exam gloves are sufficient; only chemotherapy-tested gloves rated to ASTM D6978 prevent permeation. A horizontal laminar flow hood protects the drug's sterility but blows contaminants toward the preparer — a vertical BSC protects BOTH.

Clinical Pearl

Yellow means chemo. Yellow waste bag, yellow sharps container. If it touched chemo, it goes in yellow — including the tubing primed with plain saline that later carried the drug.

General Principles

Chemotherapy kills rapidly dividing cells — cancer cells, but also bone marrow precursors, GI mucosa, and hair follicles. The nadir is the lowest point of blood cell counts after a chemotherapy cycle, typically occurring 7–14 days post-administration depending on the agent. The absolute neutrophil count (ANC) is the critical lab: ANC = (% neutrophils + % bands) × WBC. An ANC below 1,000/mm³ is neutropenia; below 500/mm³ is severe neutropenia with high infection risk. Neutropenic precautions include private room, no fresh flowers or raw fruits/vegetables, strict hand hygiene (the single most effective intervention), no rectal temperatures or suppositories, and avoiding IM injections. The classic danger sign is fever — even low-grade (≥100.4°F / 38°C) in a neutropenic patient is a medical emergency requiring immediate blood cultures and broad-spectrum antibiotics. These patients cannot mount a normal inflammatory response, so classic infection signs like redness, swelling, and purulent drainage may be absent. Fever may be the only indicator of sepsis.

Key Distinctions

Don't confuse nadir (the lowest WBC/ANC point, days 7–14) with onset of side effects (nausea can start within hours). Students think a normal WBC means the patient is safe, but you must calculate the ANC — a WBC of 3,000 with only 10% neutrophils gives an ANC of just 300. A neutropenic fever is treated as sepsis until proven otherwise, not watched and reassessed.

Clinical Pearl

No pus, no redness, no problem? Wrong. A neutropenic patient can't make inflammation — fever alone is your fire alarm. Treat it like sepsis.

Cardiotoxic Agents

Doxorubicin (Adriamycin) is an anthracycline antibiotic that intercalates DNA and generates free radicals, destroying rapidly dividing cells. The critical nursing concern is cumulative, dose-dependent cardiotoxicity. Free radicals damage cardiac myocytes, which cannot regenerate. Cardiotoxicity presents in two forms: acute (during or shortly after infusion — transient arrhythmias, ECG changes) and chronic (weeks to years later — irreversible cardiomyopathy progressing to heart failure). The lifetime cumulative dose limit is 550 mg/m²; exceeding it dramatically increases heart failure risk. Before therapy begins, a baseline ejection fraction (EF) is obtained via echocardiogram or MUGA scan, with serial monitoring throughout treatment. An EF dropping below 50% or declining ≥10% from baseline warrants holding the drug and notifying the provider. Dexrazoxane is a cardioprotective agent sometimes given before doxorubicin to chelate iron and reduce free radical formation in cardiac tissue. The nurse monitors for signs of heart failure at every visit: weight gain, peripheral edema, dyspnea, jugular vein distention, crackles, and decreasing exercise tolerance. Patient teaching includes daily weights, reporting new shortness of breath immediately, and understanding that cardiac monitoring will continue even after chemotherapy ends because late-onset cardiomyopathy can appear months to years later.

Key Distinctions

Don't confuse doxorubicin's chronic cardiotoxicity (cumulative, irreversible cardiomyopathy) with acute infusion-related arrhythmias (transient, usually self-limiting). Students often mix up the cardioprotectant dexrazoxane with mesna (which protects the bladder from cyclophosphamide, a sibling atom topic). The red-orange discoloration of urine from doxorubicin is expected, not hematuria — teach the patient before the first dose so they don't panic.

Clinical Pearl

Think of doxorubicin like sunburn on the heart — each dose adds damage that never fully heals. Once you hit the lifetime cap, the heart can't take any more.

Nephrotoxic & Ototoxic Agents

Cisplatin is a platinum-based alkylating-like agent used for testicular, ovarian, bladder, and lung cancers. Its two signature toxicities are nephrotoxicity and ototoxicity, both dose-related and potentially irreversible. Cisplatin damages renal tubular cells directly, causing acute tubular necrosis. BUN and creatinine must be checked before each cycle — the drug is held if creatinine clearance falls below the provider-specified threshold (commonly CrCl < 60 mL/min). The primary nursing prevention strategy is aggressive IV hydration with normal saline (often 1–2 L) before and after infusion, plus forced diuresis with mannitol in some protocols, to flush platinum metabolites through the tubules quickly. Urine output must be maintained at ≥100 mL/hr during and after administration. Monitor serum magnesium and potassium — cisplatin causes renal tubular wasting of both electrolytes, and hypomagnesemia is a commonly tested complication. Ototoxicity presents as high-frequency hearing loss and tinnitus, often permanent. Baseline and serial audiometry are standard. The patient should report any ringing, muffled hearing, or difficulty hearing high-pitched sounds immediately. Carboplatin, a related platinum agent, is less nephrotoxic and ototoxic but carries higher myelosuppression risk — this swap matters clinically when renal function declines.

Key Distinctions

Don't confuse cisplatin's nephrotoxicity (renal tubular damage prevented by hydration) with cyclophosphamide's bladder toxicity (hemorrhagic cystitis prevented by mesna) — different organs, different protectants. Students mix up cisplatin ototoxicity (high-frequency hearing loss, irreversible) with aminoglycoside ototoxicity (vestibular and cochlear) — cisplatin is primarily cochlear. Carboplatin is NOT interchangeable with cisplatin regarding toxicity profile: less renal/oto, more marrow suppression.

Clinical Pearl

Flood the kidneys, save the kidneys. If urine output drops below 100 mL/hr during cisplatin, intervene immediately — the tubules are sitting in poison.

Neurotoxic Agents

Vincristine is a vinca alkaloid that works by binding tubulin and disrupting microtubule formation, which arrests cell division in metaphase. Its dose-limiting toxicity is peripheral neurotoxicity, not myelosuppression — a critical distinction from most other chemotherapy agents. Neurotoxicity is cumulative and presents in a predictable pattern: peripheral neuropathy appears first (numbness, tingling, loss of deep tendon reflexes starting in the fingers and toes), then autonomic neuropathy follows (constipation progressing to paralytic ileus, urinary retention, orthostatic hypotension). Constipation must be taken seriously — a paralytic ileus can become a surgical emergency. Vincristine is administered IV only and is fatal if given intrathecally. The maximum single adult dose is typically capped at 2 mg to limit neurotoxicity. You assess baseline neurological function before each cycle: grip strength, foot sensation, DTRs, and bowel patterns. A prophylactic bowel regimen (stool softeners, stimulant laxatives) should be initiated at treatment start, not after constipation develops.

Key Distinctions

Don't confuse vincristine's dose-limiting toxicity (neurotoxicity) with most other chemo agents where myelosuppression is dose-limiting — vincristine causes relatively mild bone marrow suppression. Students mix up vincristine (neurotoxic) with vinblastine (myelosuppressive) — remember vincristine = nerves. Never confuse the IV-only route with intrathecal administration — intrathecal vincristine is universally fatal.

Clinical Pearl

VinCRISTINE = Cripples Nerves. If the patient can't feel their feet or hasn't had a bowel movement, the vincristine is talking — listen.

Hemorrhagic Cystitis & Mucositis

Cyclophosphamide is an alkylating agent used in cancer treatment and severe autoimmune conditions. Its liver metabolism produces acrolein, a toxic byproduct that accumulates in urine and directly damages the bladder mucosa, causing hemorrhagic cystitis — presenting as dysuria, urinary frequency, and frank hematuria that can become life-threatening. The key nursing intervention is aggressive hydration (typically 3 L/day or IV fluids) to dilute acrolein and promote frequent voiding. Mesna (sodium 2-mercaptoethane sulfonate) is the specific uroprotectant: it binds acrolein in the bladder, neutralizing it before damage occurs. Mesna is given IV or orally, timed with cyclophosphamide doses. Patients must void every 1–2 hours during and after infusion — holding urine concentrates acrolein. Mucositis is the other hallmark adverse effect across many chemotherapy agents but is prominent with cyclophosphamide and methotrexate. Rapidly dividing mucosal cells in the mouth and GI tract are destroyed, causing painful oral ulceration, difficulty swallowing, and infection risk. Nursing care includes oral assessments using a standardized tool before each cycle, soft-bristle toothbrushes, bland rinses (normal saline or sodium bicarbonate — never alcohol-based mouthwash), and cryotherapy (ice chips during short infusions to vasoconstrict oral mucosa and reduce drug delivery to those tissues).

Key Distinctions

Don't confuse hemorrhagic cystitis (acrolein damage to bladder, prevented with mesna and hydration) with nephrotoxicity from cisplatin (direct renal tubular damage, prevented with pre/post hydration and monitoring creatinine). Students mix up mesna (uroprotectant for cyclophosphamide) with dexrazoxane (cardioprotectant for doxorubicin). Mucositis management uses saline or bicarb rinses — never commercial alcohol-based mouthwash, which worsens tissue breakdown.

Clinical Pearl

Mesna saves the bladder, dexrazoxane saves the heart. Match the protectant to the poison: acrolein → mesna, doxorubicin → dexrazoxane.

Chemotherapy Side Effects

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 patient 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 patient 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.