Chemotherapy looks intimidating on NAPLEX, but the exam repeats the same regimens and the same adverse-effect signals. If you can recognize five core protocols and the toxicities that drive monitoring and rescue strategies, most oncology questions become pattern recognition. Below are the regimens, the “why” behind each component, and the high-yield side effects that show up again and again.
1) R-CHOP for Diffuse Large B-Cell Lymphoma
What it is: Rituximab + Cyclophosphamide + Doxorubicin (Hydroxydaunorubicin) + Vincristine (Oncovin) + Prednisone, given every 21 days.
- Rituximab: Targets CD20 on B cells. Premedicate (acetaminophen + antihistamine) to prevent infusion reactions. Screen for hepatitis B; reactivation can be fatal.
- Cyclophosphamide: Alkylator. Can cause hemorrhagic cystitis via acrolein. Prevent with hydration; mesna is required for ifosfamide and high-dose cyclophosphamide.
- Doxorubicin: Anthracycline. Dose-dependent cardiomyopathy; track lifetime dose (typically 450–550 mg/m²). Consider dexrazoxane when cumulative dose is high or for extravasation.
- Vincristine: Vinca alkaloid. Dose-limiting peripheral neuropathy and severe constipation/ileus. Do not give intrathecally. Max 2 mg per cycle in most protocols.
- Prednisone: Improves response and reduces chemo-induced nausea; watch glucose and mood changes.
Why it’s tested: R-CHOP bundles multiple classic toxicities: infusion reaction (rituximab), hemorrhagic cystitis (cyclophosphamide), cardiomyopathy (doxorubicin), and neurotoxicity/constipation (vincristine). Vignettes often ask for the right prevention (premeds, hydration, stool softeners) or the correct antidote (dexrazoxane).
2) FOLFOX and FOLFIRI for Colorectal Cancer
What they are:
- FOLFOX: Leucovorin (folinic acid) + 5-Fluorouracil + Oxaliplatin
- FOLFIRI: Leucovorin + 5-Fluorouracil + Irinotecan
Key pharmacology:
- Leucovorin boosts 5-FU binding to thymidylate synthase, increasing cytotoxicity. That’s why it is used with 5-FU, but it rescues cells from high-dose methotrexate (different mechanism). The exam loves this contrast.
- 5-FU: Hand–foot syndrome, mucositis, myelosuppression. Patients with DPD deficiency are at risk of severe toxicity.
- Oxaliplatin: Acute cold-induced neuropathy (throat spasms, jaw tightness). Counsel to avoid cold drinks/exposure for 48 hours after infusion.
- Irinotecan: Two diarrheas: acute cholinergic (treat with atropine) and delayed secretory (treat with high-dose loperamide). UGT1A1*28 variants increase neutropenia risk.
Why it’s tested: Questions pair symptoms with the agent. Cold-triggered dysesthesia? Think oxaliplatin. “Cramping and tearing” during infusion? Give atropine for irinotecan. Severe mucositis and palms peeling? That’s 5-FU.
3) AC→T for Breast Cancer (with HER2 Add-ons)
What it is: Doxorubicin + Cyclophosphamide, then Paclitaxel (AC→T). HER2-positive disease often adds trastuzumab (± pertuzumab) in an anthracycline-sparing regimen (e.g., TCHP), but AC→T is foundational.
- Doxorubicin + Cyclophosphamide: Curative intent in early-stage disease. Watch cardiotoxicity and cystitis risks as above.
- Paclitaxel: Peripheral neuropathy is common. Hypersensitivity reactions are due to the Cremophor solvent—premedicate with steroid + H1 + H2 blockers. Docetaxel causes less hypersensitivity but notable fluid retention; premedicate with dexamethasone.
- Trastuzumab (HER2): Reversible cardiomyopathy; monitor LVEF every 3 months. Avoid concurrent anthracycline because cardiotoxicity is additive.
Why it’s tested: The exam stresses sequencing and cardiac safety. If LVEF drops on trastuzumab, hold the drug. Never overlap trastuzumab and doxorubicin. Recognize paclitaxel hypersensitivity and neuropathy.
4) “7+3” for Acute Myeloid Leukemia (AML)
What it is: Cytarabine for 7 days + an anthracycline (daunorubicin or idarubicin) for 3 days as induction therapy.
- Cytarabine: High-dose therapy causes cerebellar toxicity (ataxia) and conjunctivitis; give steroid eye drops prophylactically at high doses and perform neuro checks.
- Anthracycline: Same cardiomyopathy and extravasation risks as doxorubicin in other regimens; lifetime limits still matter.
- Tumor Lysis Syndrome (TLS): AML has high TLS risk during induction. Prevent with aggressive IV hydration and allopurinol. Treat high uric acid or established TLS with rasburicase. Monitor potassium, phosphate, calcium, and creatinine closely.
Why it’s tested: Two predictable patterns: eye drops and neuro exams with high-dose cytarabine, and TLS prevention/management during induction.
5) BEP for Testicular Cancer
What it is: Bleomycin + Etoposide + Cisplatin.
- Bleomycin: Pulmonary fibrosis risk; lifetime max around 400 units. Get baseline and periodic PFTs. High oxygen concentrations can worsen lung injury—important in anesthesia settings.
- Etoposide: Myelosuppression; rare secondary AML with long-term exposure.
- Cisplatin: Nephrotoxicity, severe nausea/vomiting, ototoxicity, and neuropathy. Prevent kidney injury with vigorous hydration and magnesium/potassium repletion; consider mannitol for diuresis. Emetic risk is high—use a 3–4 drug antiemetic regimen.
Why it’s tested: The exam links bleomycin to lungs and cisplatin to kidneys/ears. Expect questions on hydration orders, electrolyte replacement, and emesis prophylaxis with cisplatin.
Adverse Effects You Must Know Cold
- Anthracyclines (doxorubicin, daunorubicin): Cumulative cardiomyopathy; red urine discoloration; vesicants if extravasated. Dexrazoxane for cardioprotection (select patients) and for extravasation.
- Alkylators (cyclophosphamide/ifosfamide): Hemorrhagic cystitis. Mesna + hydration prevent ifosfamide toxicity and high-dose cyclophosphamide toxicity.
- Vinca alkaloids (vincristine, vinblastine): Peripheral neuropathy; constipation/ileus (vincristine). Never intrathecal.
- Platinum agents: Cisplatin (nephrotoxicity, ototoxicity, severe emesis), Carboplatin (thrombocytopenia; dose by Calvert formula), Oxaliplatin (cold neuropathy).
- Antimetabolites: Methotrexate (mucositis, myelosuppression, hepatotoxicity; renal elimination). Use leucovorin rescue for high-dose MTX and ensure alkalinized urine with vigorous hydration to prevent crystal nephropathy.
- Taxanes: Neuropathy; hypersensitivity (paclitaxel); fluid retention (docetaxel).
- Bleomycin: Pulmonary fibrosis; minimal myelosuppression (a favorite board contrast).
- 5-FU/Capecitabine: Hand–foot syndrome, mucositis, diarrhea; cardiac ischemia can occur.
- Irinotecan: Early cholinergic diarrhea (atropine) and late secretory diarrhea (loperamide).
- Monoclonal antibodies: Infusion reactions common; premedicate when appropriate. Rituximab requires HBV screening. Trastuzumab causes cardiomyopathy (monitor LVEF).
- Checkpoint inhibitors (pembrolizumab, nivolumab): Immune-mediated toxicities (colitis, hepatitis, pneumonitis, endocrinopathies). Treat moderate–severe cases with corticosteroids; hold immunotherapy.
Supportive Care Patterns That Show Up on Every Exam
- CINV prophylaxis:
- High emetic risk (cisplatin, high-dose anthracycline/cyclophosphamide): Use 3–4 drugs—NK1 antagonist (e.g., aprepitant), 5-HT3 antagonist, dexamethasone, ± olanzapine.
- Moderate risk: 2–3 drugs (5-HT3 antagonist + dexamethasone ± NK1 antagonist or olanzapine).
- Low risk: Single agent (often dexamethasone or 5-HT3 antagonist).
- Always consider delayed emesis coverage for cisplatin (continue dexamethasone, NK1, and/or olanzapine on days 2–4).
- Tumor Lysis Syndrome: Prevent with hydration and allopurinol in high-risk regimens (e.g., AML induction). Treat with rasburicase if uric acid is high or TLS is present. Avoid routine IV calcium in hyperphosphatemia until phosphate is controlled.
- Growth factors (G-CSF): Primary prophylaxis when febrile neutropenia risk ≥20% or 10–20% with patient risk factors (age, comorbidities, prior FN). Administer 24–72 hours after chemotherapy, not on the same day.
- Extravasation management:
- Anthracyclines: Cold compresses + dexrazoxane.
- Vinca alkaloids and taxanes: Warm compresses + hyaluronidase for vinca agents.
- Vaccines: No live vaccines during chemotherapy; give inactivated vaccines when neutrophil counts have recovered.
Quick Calculation and Dosing Triggers
- BSA dosing: Most IV chemo uses mg/m². Be comfortable calculating BSA and cumulative doses.
- Anthracycline lifetime limits: Doxorubicin 450–550 mg/m² (lower if prior chest radiation or cardiac disease). Epirubicin roughly 900 mg/m². Stop or add dexrazoxane as thresholds approach.
- Carboplatin dosing: Calvert formula = Target AUC × (GFR + 25). GFR is often estimated by creatinine clearance.
- Vincristine cap: Do not exceed 2 mg per dose because neuropathy scales with dose, not BSA.
- Methotrexate rescue: Start leucovorin at scheduled time post-infusion, and continue until MTX levels are safe. Maintain urine pH ≥7 and high urine output.
How to Tackle Oncology Questions Fast
- Identify the regimen by one giveaway drug (vincristine → R-CHOP; oxaliplatin → FOLFOX; bleomycin → BEP; cytarabine → AML induction; paclitaxel after AC → breast).
- Match the symptom to the culprit: Cold throat spasms → oxaliplatin. Immediate cramping/diarrhea → irinotecan (atropine). Red urine and declining LVEF → anthracycline. New cough + low DLCO → bleomycin.
- Pick the prevention/rescue: Mesna for ifosfamide/high-dose cyclophosphamide; dexrazoxane for anthracyclines; leucovorin to rescue MTX (and to enhance 5-FU); atropine/loperamide for irinotecan; hydration/electrolytes for cisplatin; HBV screen for rituximab.
- Don’t forget timing: G-CSF 24–72 hours after chemo; avoid overlapping trastuzumab with anthracycline; avoid cold exposure after oxaliplatin for 48 hours.
Master these five protocols and their predictable toxicities, and you turn most oncology questions into quick, safe decisions. The patterns do not change: know the drug, anticipate the harm, and choose the preventive step or antidote the test is pointing to.
I am a Registered Pharmacist under the Pharmacy Act, 1948, and the founder of PharmacyFreak.com. I hold a Bachelor of Pharmacy degree from Rungta College of Pharmaceutical Science and Research. With a strong academic foundation and practical knowledge, I am committed to providing accurate, easy-to-understand content to support pharmacy students and professionals. My aim is to make complex pharmaceutical concepts accessible and useful for real-world application.
Mail- Sachin@pharmacyfreak.com