ONCOLOGY SAFETY LAB
Connect the drug.
Recognize the risk.
Remember the response.
Explore chemotherapy toxicities and supportive care, then put the patterns to work in short practice cases.
A foundation for healthcare learning. Not an exhaustive oncology reference or a patient-specific treatment plan.
Free oncology foundations. Explore 17 safety cards and 15 practice cases. Source dates and references are included with each topic; use the report link beside a question if something needs our attention.
EXPLORE BY SYSTEM
One drug. More than one risk.
Select a system on this schematic, or use the text filter. Some drugs affect several systems.
Illustration is schematic; button positions do not represent the full distribution of a toxicity.
17 of 17 cards shown.
DoxorubicinHeart · Skin
- How it works
- Anthracycline: intercalates DNA and interferes with topoisomerase II.
- What to watch for
- Cumulative cardiomyopathy and tissue injury after extravasation.
- Prevention, monitoring or response
- Assess left ventricular function before, during and after therapy; track prior anthracycline exposure.
- Patient counseling
- Report breathlessness, swelling or infusion-site pain promptly. Red urine for 1–2 days can be expected discoloration, but blood or clots, painful urination or persistent discoloration require prompt contact—even during that period.
Sources and dates
Doxorubicin hydrochloride injection labeling
5.1 cardiomyopathy; 5.3 extravasation; 12.1 mechanism; 17 and Patient Information counseling
PI highlights 7/2024; current retrieved SPL also contains later packaging revision dates. Source checked 2026-09-13.
BleomycinLungs
- How it works
- Causes DNA strand breaks.
- What to watch for
- Pneumonitis and pulmonary fibrosis; risk rises with exposure but lower doses are not risk-free.
- Prevention, monitoring or response
- Assess new respiratory symptoms promptly. A cumulative-dose number alone cannot exclude toxicity.
- Patient counseling
- Tell the surgical/anesthesia team about prior bleomycin. Report new cough or shortness of breath.
Sources and dates
Bleomycin labeling
Clinical Pharmacology; Warnings; Adverse Reactions: Pulmonary; Dosage and Administration
PI March 2026. Source checked 2026-09-13.
CisplatinKidneys · Nerves
- How it works
- Platinum compound that forms DNA cross-links.
- What to watch for
- Kidney injury, magnesium loss, hearing damage and peripheral neuropathy.
- Prevention, monitoring or response
- Provide prescribed hydration; monitor renal function/electrolytes and hearing as indicated. Use effective antiemetic prophylaxis.
- Patient counseling
- Report ringing ears, hearing changes, numbness or reduced urine output.
Sources and dates
Cisplatin injection labeling
2.1 hydration; 5.1 renal; 5.6 hearing; 6.2 electrolyte wasting; 12.1 mechanism; 17 counseling
PI highlights 12/2023. Source checked 2026-09-13.
OxaliplatinNerves
- How it works
- Platinum compound that cross-links DNA.
- What to watch for
- Acute cold-triggered sensory symptoms and cumulative neuropathy.
- Prevention, monitoring or response
- Monitor persistent sensory changes and functional impairment. Throat or breathing symptoms need assessment, including for hypersensitivity.
- Patient counseling
- Avoid cold drinks, ice and cold objects around treatment as instructed. Do not assume every breathing symptom is harmless cold sensitivity.
Sources and dates
Oxaliplatin labeling
5.1 hypersensitivity; 5.2 neuropathy; 12.1 mechanism; 17 counseling
PI highlights 6/2024. Source checked 2026-09-13.
VincristineNerves · Gut
- How it works
- Vinca alkaloid that disrupts microtubules and the mitotic spindle.
- What to watch for
- Peripheral/autonomic neuropathy, constipation and ileus; wrong-route administration can be fatal.
- Prevention, monitoring or response
- Use intravenous administration in a flexible container with route safeguards. Assess bowel function and neurologic symptoms.
- Patient counseling
- Report severe constipation, abdominal distension, weakness or new numbness.
Sources and dates
Vincristine sulfate injection labeling
Boxed warning; Clinical Pharmacology; Precautions; Adverse Reactions; Dosage and Administration
12/2025. Source checked 2026-09-13.
Irinotecan — conventional formulationGut · Blood
- How it works
- Irinotecan and SN-38 inhibit topoisomerase I.
- What to watch for
- Early cholinergic diarrhea differs from potentially severe delayed diarrhea.
- Prevention, monitoring or response
- Atropine can treat early cholinergic symptoms if appropriate. Delayed diarrhea needs prompt prescribed antidiarrheal treatment, hydration and assessment.
- Patient counseling
- Use the oncology team’s diarrhea plan. Fever, inability to drink or persistent diarrhea needs urgent contact.
Sources and dates
Conventional irinotecan hydrochloride injection labeling
5.1 early/late diarrhea; 12.1 mechanism; 17 counseling
PI highlights 9/2022. Source checked 2026-09-13.
Fluorouracil / capecitabineGut · Skin · Blood
- How it works
- Fluorouracil metabolites inhibit thymidylate synthase and disrupt RNA/DNA. Capecitabine is converted to fluorouracil.
- What to watch for
- DPD deficiency can cause early severe or fatal toxicity; diarrhea, mucositis and hand-foot symptoms need attention.
- Prevention, monitoring or response
- Test DPYD variants before treatment unless immediate therapy is necessary. Avoid use when variants cause complete DPD deficiency; individualize treatment for partial deficiency. A negative test does not eliminate severe-toxicity risk.
- Patient counseling
- Promptly report severe early diarrhea, mouth sores or neurologic symptoms. Do not independently adjust doses.
Sources and dates
Fluorouracil injection labeling
2.1 DPYD testing; 5.1 DPD deficiency; 5.5–5.8; 12.1; 17
11/2025. Source checked 2026-09-13.
FDA fluoropyrimidine DPD safety-labeling update
Healthcare-provider recommendations; summary of boxed warning, dosage and precautions
FDA communication content date 2026-02-05. Source checked 2026-09-13.
Xeloda (capecitabine) labeling
2.1 DPYD testing; 5.1 DPD deficiency; 12.1 mechanism
2/2026. Source checked 2026-09-13.
Mesna with ifosfamideBladder
- How it works
- Binds urotoxic metabolites, including acrolein.
- What to watch for
- Reduces hemorrhagic cystitis risk; does not protect against every ifosfamide toxicity.
- Prevention, monitoring or response
- Continue hydration, urine monitoring and the prescribed mesna schedule. Protection is incomplete.
- Patient counseling
- Report pink/red urine or urinary symptoms. Mesna is not a substitute for monitoring.
Sources and dates
Mesna injection labeling
1; 2.3 hematuria monitoring; 12.1 mechanism; 17 counseling
PI highlights 11/2025. Source checked 2026-09-13.
Ifosfamide for injection labeling
5.2 encephalopathy; 5.3 nephrotoxicity and urotoxicity
PI 12/2024. Source checked 2026-09-13.
Glucarpidase and leucovorin timingKidneys
- How it works
- Glucarpidase enzymatically breaks down circulating methotrexate through a nonrenal pathway.
- What to watch for
- Used for toxic methotrexate concentrations with delayed clearance from impaired renal function.
- Prevention, monitoring or response
- Continue prescribed hydration/alkalinization and leucovorin rescue. Separate leucovorin by at least 2 hours before or after glucarpidase.
- Patient counseling
- For methotrexate measurement during the first 48 hours after glucarpidase, use a chromatographic method. The breakdown product DAMPA can falsely elevate immunoassay results.
Sources and dates
Voraxaze (glucarpidase) labeling
1 indications; 2.2 supportive care/leucovorin timing; 5.2 assay interference; 12.1 mechanism
PI highlights 8/2019. Source checked 2026-09-13.
RasburicaseKidneys · Blood
- How it works
- Converts uric acid to allantoin.
- What to watch for
- G6PD deficiency is a contraindication because hemolysis can occur; methemoglobinemia is another serious risk.
- Prevention, monitoring or response
- Screen patients at higher risk for G6PD deficiency before therapy; known deficiency contraindicates use. For uric-acid testing, collect blood in prechilled heparin tubes, immediately keep it in an ice-water bath, prepare plasma in a precooled 4°C centrifuge, keep plasma in ice water and assay within 4 hours of blood collection.
- Patient counseling
- Report breathing difficulty or a severe reaction urgently. Continued breakdown of uric acid in a mishandled sample can produce a falsely low result; specimen handling does not prevent patient hemolysis.
Sources and dates
Elitek (rasburicase) labeling
Boxed warning; 4; 5.2 hemolysis; 5.3 methemoglobinemia; 5.4 specimen handling; 7 laboratory interference; 12.1
PI highlights 5/2025. Source checked 2026-09-13.
Uridine triacetateGut · Blood
- How it works
- Supplies uridine that competes with fluorouracil-related RNA toxicity.
- What to watch for
- Emergency rescue after fluoropyrimidine overdose or qualifying early severe toxicity.
- Prevention, monitoring or response
- Start indicated rescue as soon as possible and within 96 hours after fluorouracil or capecitabine administration ends. Safety and efficacy when started later are not established.
- Patient counseling
- Do not wait for symptoms after an overdose. This is not routine prevention of ordinary treatment adverse effects.
Sources and dates
Vistogard (uridine triacetate) labeling
1 emergency indications/limitations; 2.1 timing; 12.1 mechanism
PI highlights 10/2023. Source checked 2026-09-13.
Prevention of severe nausea and vomitingGut
- How it works
- A 5-HT3 antagonist such as ondansetron blocks serotonin signaling at that receptor; an NK1 antagonist such as aprepitant blocks substance-P signaling. Olanzapine acts at several receptor types. Dexamethasone adds antiemetic benefit; a single definitive mechanism is not asserted here.
- What to watch for
- Highly emetogenic treatment such as cisplatin needs preventive treatment.
- Prevention, monitoring or response
- For adult non-AC highly emetogenic chemotherapy, MASCC/ESMO recommends a 5-HT3 antagonist, NK1 antagonist, dexamethasone and olanzapine before treatment.
- Patient counseling
- Follow the full prevention/rescue schedule. Report uncontrolled vomiting; the regimen must account for sedation, interactions and patient factors.
Sources and dates
2023 MASCC/ESMO antiemetic guideline update
Recommendations: acute nausea/vomiting after non-AC high-emetic-risk chemotherapy
2023 guideline update; article published 2024. Source checked 2026-09-13.
Ondansetron oral labeling — receptor pharmacology
12.1 mechanism
PI highlights 8/2025; later patient-leaflet revision is separate. Source checked 2026-09-13.
Aprepitant oral labeling — receptor pharmacology
12.1 mechanism
PI highlights 5/2025; later SPL/packaging dates are separate. Source checked 2026-09-13.
Olanzapine oral labeling — receptor pharmacology
12.1 mechanism; 12.2 receptor pharmacodynamics
PI highlights 4/2026; later patient-leaflet/SPL dates are separate. Source checked 2026-09-13.
PegfilgrastimBlood
- How it works
- Granulocyte colony-stimulating factor stimulates neutrophil production and function.
- What to watch for
- Prevention of febrile neutropenia in indicated settings; bone pain is common.
- Prevention, monitoring or response
- For labeled chemotherapy use, avoid administration from 14 days before until 24 hours after chemotherapy. Neulasta Onpro delivery starts about 27 hours after application and lasts about 45 minutes; verify actual delivery meets the chemotherapy interval.
- Patient counseling
- Report left upper abdominal or shoulder pain promptly. An on-body device problem or missed dose needs the care team.
Sources and dates
Neulasta (pegfilgrastim) labeling
2.1 chemotherapy timing; 2.4 on-body injector; 2.5 device counseling; 5.1 spleen; 6.1 bone pain; 12.1 mechanism
8/2026. Source checked 2026-09-13.
PembrolizumabImmune system · Lungs · Gut
- How it works
- Blocks programmed death-1 (PD-1), removing inhibitory PD-1 signaling and allowing a stronger immune response, including against tumors.
- What to watch for
- Immune inflammation can affect multiple organs, including after treatment stops.
- Prevention, monitoring or response
- Evaluate symptoms and alternative causes promptly. Holds, discontinuation, immunosuppression or hormone replacement depend on the organ and severity.
- Patient counseling
- Report new diarrhea, breathlessness, marked weakness or other concerning changes. Do not self-treat suspected immune toxicity.
Sources and dates
Keytruda (pembrolizumab) labeling
2.3 dose modifications; 5.1 immune-mediated events and endocrine distinctions; 12.1; Medication Guide
7/2026. Source checked 2026-09-13.
Fam-trastuzumab deruxtecan-nxkiLungs · Heart · Blood
- How it works
- HER2-directed antibody-drug conjugate delivering a topoisomerase I inhibitor.
- What to watch for
- Interstitial lung disease/pneumonitis can be fatal.
- Prevention, monitoring or response
- Drug-related symptomatic Grade 2 or higher ILD/pneumonitis requires permanent discontinuation and prompt systemic corticosteroid treatment. The current adjuvant-setting table separately addresses radiotherapy-only pneumonitis: consider interruption for Grade 2 and permanently discontinue for Grade 3 or higher. Prompt evaluation must distinguish these causes.
- Patient counseling
- Report new cough, fever or shortness of breath immediately. This drug is not interchangeable with other trastuzumab products.
Sources and dates
Enhertu (fam-trastuzumab deruxtecan-nxki) labeling
Boxed warning; 2.3 Table 3 and radiotherapy-related footnote; 5.1 ILD/pneumonitis; 12.1; 17
5/2026. Source checked 2026-09-13.
Fever during chemotherapyBlood
- How it works
- Low neutrophil defenses can make infection rapidly dangerous.
- What to watch for
- Fever can be the only infection sign.
- Prevention, monitoring or response
- CDC patient counseling: contact the oncology team immediately for temperature at least 100.4°F (38°C).
- Patient counseling
- Keep daytime/after-hours numbers handy. If seeking emergency care, identify yourself as receiving chemotherapy. Do not wait to feel worse.
Sources and dates
CDC: Watch Out for Fever
Key points; Steps to take
Page dated 2024-11-14; current body retrieved 2026-09-13. Source checked 2026-09-13.
Dexrazoxane — indication mattersHeart · Skin
- How it works
- Its protective mechanism is not fully established. Intracellular conversion to an iron-chelating metabolite is proposed to reduce iron-mediated free-radical injury from anthracyclines.
- What to watch for
- Cardiac protection and treatment of anthracycline extravasation have different eligibility and administration requirements.
- Prevention, monitoring or response
- Verify the exact product and protocol. NCI distinguishes cardiac-protection use from Totect’s extravasation indication.
- Patient counseling
- Infusion-site pain or swelling needs immediate staff assessment. Do not apply one indication’s schedule to another.
Sources and dates
NCI: Dexrazoxane hydrochloride
Use in Cancer
Updated 2021-03-29. Source checked 2026-09-13.
Doxorubicin hydrochloride injection labeling
5.1 cardiomyopathy; 5.3 extravasation; 12.1 mechanism; 17 and Patient Information counseling
PI highlights 7/2024; current retrieved SPL also contains later packaging revision dates. Source checked 2026-09-13.
Dexrazoxane for injection labeling
1 cardioprotection indication; 5.3 residual cardiac risk; 12.1 proposed mechanism
2/2024. Source checked 2026-09-13.
CONNECT THE PATTERN
Name the drug before you reveal it.
Match 1 of 5. Reduces hemorrhagic cystitis risk; does not protect against every ifosfamide toxicity.
Terms and abbreviations
- DPYD
- Gene encoding dihydropyrimidine dehydrogenase
- DPD
- Dihydropyrimidine dehydrogenase, an enzyme involved in fluorouracil breakdown
- DNA
- Deoxyribonucleic acid
- RNA
- Ribonucleic acid
- G6PD
- Glucose-6-phosphate dehydrogenase
- ILD
- Interstitial lung disease
- HER2
- Human epidermal growth factor receptor 2
- PD-1
- Programmed death-1
- 5-HT3
- 5-hydroxytryptamine (serotonin) type 3 receptor
- NK1
- Neurokinin-1 receptor
- AC
- Anthracycline plus cyclophosphamide
- SN-38
- Active metabolite of irinotecan
- DAMPA
- Methotrexate breakdown product: 4-deoxy-4-amino-N10-methylpteroic acid
- OBI
- On-body injector
- IV
- Intravenous
- G-CSF
- Granulocyte colony-stimulating factor
LEARN FROM EVERY CHOICE
Fifteen cases. Three focused sets.
Take a set of five, read every explanation, and revisit the relevant cards. First-response responses save to your confirmed account after submission. These are original teaching cases, not an exam-readiness score.
KEEP LEARNING
More practice. Your progress, saved.
Try our free NAPLEX topic previews without an account. Sign in to use your membership. Review NAPLEX membership options to continue with more questions and saved progress.
Build understanding that carries forward.
Pair these safety patterns with drug fundamentals and calculation practice. More reviewed oncology cases can build on this foundation as the collection grows.