# Anticancer Drugs and Immunosuppressants for NEET PG Pharmacology: Methotrexate, Doxorubicin, Cisplatin, Imatinib, Tacrolimus Source: https://tracknation.in/story/anticancer-drugs-and-immunosuppressants-for-neet-pg-pharmacology-methotrexate-doxorubicin-cisplatin-imatinib-tacrolimus (TrackNation — free UPSC notes with PYQs) > NEET PG Pharmacology: signature toxicities and rescues of methotrexate, cyclophosphamide, doxorubicin, cisplatin, vincristine, bleomycin and 5-FU; imatinib, trastuzumab and rituximab; ICMR breast cancer hormonal and HER2 therapy; and tacrolimus, cyclosporine, mycophenolate, azathioprine and 6-mercaptopurine, with a diagram, hooks, vignette MCQs and cards. ## Start Here 🎯 **Exam priority: High.** *Expect: the rescue for methotrexate, the bladder with cyclophosphamide, the heart with doxorubicin and trastuzumab, the kidneys and ears with cisplatin, the lungs with bleomycin, vincristine given intrathecally, and 6-MP with allopurinol.* CBME mapping: **PH 8.10–8.11**. Indian protocol: **ICMR Breast Cancer workflow (July 2020)**. ## Cytotoxic Drugs: Toxicity and Rescue *Anticancer drugs: signature toxicity and its prevention or rescue, from the drugs' labels. Drawn by TrackNation.* - **Methotrexate**: embryo-fetal toxicity; stomatitis, GI toxicity, marrow suppression; deaths when taken daily instead of weekly (RA starts at 7.5 mg once weekly). Leucovorin (folinic acid) rescues at doses ≥ 500 mg/m². - **Cyclophosphamide**: haemorrhagic cystitis — drink plenty of fluids. Mesna is labelled for *ifosfamide* cystitis. - **Doxorubicin**: boxed cardiomyopathy (risk rises above 550 mg/m² cumulative), secondary malignancies, extravasation necrosis, marrow suppression. - **Cisplatin**: boxed nephrotoxicity, neuropathy, vomiting, marrow suppression; ototoxicity (worst in children); low magnesium — hydrate well. - **Vincristine**: IV only — fatal by other routes (intrathecal); neuritic pain, constipation. - **Bleomycin**: pulmonary fibrosis, usually starting as pneumonitis; idiosyncratic reaction in about 1% of lymphoma patients. - **5-FU**: test for DPYD variants — complete DPD deficiency can be fatal. ## Targeted and Hormonal Therapy | **Drug** | **Target / use** | **Key warning (label)** | | Imatinib | BCR-ABL tyrosine kinase (Philadelphia chromosome, CML) | Severe fluid retention, hepatotoxicity | | Trastuzumab | HER2-positive breast cancer (ICMR: 12 months) | Boxed cardiomyopathy: check LV function before and during | | Rituximab | Anti-CD20 | Boxed: HBV reactivation, PML, severe mucocutaneous reactions | | Tamoxifen / aromatase inhibitors | ER/PR-positive breast cancer (ICMR: ≥ 5 years) | Premenopausal tamoxifen; postmenopausal tamoxifen or AI | ## Immunosuppressants | **Drug** | **Key warning (label)** | | Tacrolimus | Boxed malignancy and infection; nephrotoxicity; new-onset diabetes after transplant | | Cyclosporine | Renal dysfunction, tremor, hirsutism, hypertension, gum hyperplasia | | Mycophenolate | Boxed: first-trimester miscarriage and malformations | | Azathioprine | Inactivated by TPMT; reduce with allopurinol; boxed malignancy | | 6-Mercaptopurine | Cut to one-third to one-quarter with allopurinol; check TPMT/NUDT15 if marrow suppression | ## Traps the Examiner Sets - Leucovorin rescues methotrexate; methotrexate for RA is weekly, never daily. - Mesna is for ifosfamide (and fluids for cyclophosphamide). - Doxorubicin and trastuzumab both hit the heart. - Vincristine intrathecally is fatal. - Allopurinol with 6-MP or azathioprine → cut the dose. ## Memory Hooks & Shortcuts *Shortcuts to lock in this article's numbers and lists. Each one only re-packages facts proven above.* - 🧠 **Leucovorin Lifts methotrexate's Lid** — rescue - 🧠 **Cyclophosphamide Cries blood (bladder)** — haemorrhagic cystitis - 🧠 **Dox Damages the heart past 550** — cumulative cardiomyopathy - 🧠 **Cisplatin: Kidneys, Ears, Nerves** — nephro-, oto-, neurotoxicity - 🧠 **Vincristine: Veins only** — fatal intrathecally - 🧠 **Bleomycin Bruises the lungs** — pulmonary fibrosis - 🧠 **Allopurinol + purines: Pare down** — reduce azathioprine/6-MP ## Rapid-Revision Cards - Leucovorin at ≥ 500 mg/m². - Weekly, not daily; deaths reported. - Haemorrhagic cystitis; fluids. - Ifosfamide cystitis. - Cardiomyopathy > 550 mg/m²; extravasation; 2nd cancers. - Kidney, ears, nerves, vomiting, low Mg; hydrate. - IV only; neuropathy, constipation. - Pneumonitis → fibrosis. - DPYD test; DPD deficiency fatal. - BCR-ABL; fluid retention. - HER2; cardiomyopathy; ICMR 12 months. - Anti-CD20; HBV reactivation, PML. - Premenopausal tamoxifen; post: tamoxifen or AI; ≥ 5 y. - Nephrotoxicity, NODAT; boxed infection/malignancy. - Kidney, tremor, hirsutism, BP, gum hyperplasia. - Miscarriage, malformations. - Cut dose; TPMT. - Reduce to 1/3–1/4; TPMT/NUDT15. ## Sources *Facts in this article were checked against these documents.* - Standard Treatment Workflow: Breast Cancer — Indian Council of Medical Research / Department of Health Research, MoHFW, July 2020 - Prescribing labels: methotrexate, leucovorin, cyclophosphamide, Mesnex, doxorubicin, cisplatin, vincristine, bleomycin, fluorouracil, Gleevec, Herceptin Hylecta, Rituxan Hycela, Prograf, Sandimmune, CellCept, Imuran, mercaptopurine — DailyMed, US National Library of Medicine, current labels, accessed November 2026 (link) - Competency Based Undergraduate Curriculum, Pharmacology (PH 8.10–8.11) — National Medical Commission, 2024 ## Test Yourself: Practice Questions Twenty-four questions in NEET PG style, most of them clinical vignettes. ## Practice Questions (NEET PG pattern) *Original questions written in the style of the exam: +4 for a correct answer, −1 for a wrong one. Every answer was checked against the sources listed above. NEET PG papers are not published by NBEMS, so these are not past-paper questions.* **Q1.** A patient receives high-dose methotrexate (1 g/m²) for osteosarcoma. To prevent toxicity, give - (a) dexrazoxane only - (b) leucovorin rescue - (c) mesna - (d) allopurinol only **Answer: (b)** — Leucovorin rescue for doses ≥ 500 mg/m²; it is an antidote to folic acid antagonists. **Q2.** An elderly woman with rheumatoid arthritis mistakenly takes her methotrexate every day instead of once weekly and develops mouth ulcers and pancytopenia. The label notes - (a) daily dosing is preferred - (b) only mouth ulcers occur - (c) this is harmless - (d) daily-for-weekly errors have caused deaths **Answer: (d)** — RA starting dose: 7.5 mg once weekly. **Q3.** A woman on cyclophosphamide develops painful frank haematuria. This is - (a) bladder cancer from 5-FU - (b) haemorrhagic cystitis — prevented by adequate fluids - (c) a kidney stone - (d) a UTI only **Answer: (b)** — Cyclophosphamide label; mesna is labelled for ifosfamide-induced cystitis. **Q4.** Mesna, per its label, reduces haemorrhagic cystitis caused by - (a) ifosfamide - (b) methotrexate - (c) vincristine - (d) doxorubicin **Answer: (a)** — Mesnex label. **Q5.** A lymphoma survivor treated with doxorubicin presents years later with heart failure. The label links cardiomyopathy risk to - (a) hypokalaemia only - (b) cumulative doses above 550 mg/m² - (c) a single small dose - (d) concomitant mesna **Answer: (b)** — Boxed: cardiomyopathy, secondary malignancies, extravasation necrosis, myelosuppression. **Q6.** A child receiving cisplatin develops hearing loss. The label advises - (a) nothing - (b) audiometric and vestibular monitoring (ototoxicity is cumulative, worse in children) - (c) doubling the dose - (d) adding furosemide **Answer: (b)** — Also nephrotoxicity — hydrate; low magnesium. **Q7.** To reduce cisplatin nephrotoxicity, the label stresses - (a) giving with NSAIDs - (b) fluid restriction - (c) giving with aminoglycosides - (d) adequate hydration and monitoring of renal function and electrolytes **Answer: (d)** — Toxicities are dose-related and cumulative. **Q8.** In a leukaemia ward, a syringe of vincristine is about to be given into the spinal canal with intrathecal methotrexate. The label says vincristine is - (a) safe intrathecally - (b) for IV use only — fatal by other routes - (c) given IM - (d) preferred intrathecally **Answer: (b)** — A never event. **Q9.** A man on vincristine complains of nerve pain and constipation. These are - (a) unrelated - (b) caused by mesna - (c) signs of vincristine overdose only - (d) known vincristine toxicities **Answer: (d)** — Neuropathy is vincristine's unique toxicity. **Q10.** A young man treated with bleomycin for testicular cancer develops dry cough and breathlessness. The concern is - (a) TB - (b) bleomycin pneumonitis progressing to pulmonary fibrosis - (c) asthma - (d) heart failure from bleomycin **Answer: (b)** — Pulmonary fibrosis is bleomycin's most severe toxicity. **Q11.** A patient with colon cancer has severe life-threatening toxicity after the first 5-FU dose. The label recommends beforehand - (a) TPMT testing - (b) testing for DPYD variants (DPD deficiency) - (c) G6PD testing - (d) HLA-B*5701 testing **Answer: (b)** — Complete DPD deficiency increases the risk of serious reactions or death. **Q12.** Imatinib in chronic myeloid leukaemia inhibits - (a) topoisomerase II - (b) the BCR-ABL tyrosine kinase - (c) CD20 - (d) HER2 **Answer: (b)** — Product of the Philadelphia chromosome. **Q13.** A woman with HER2-positive breast cancer is starting trastuzumab. Before and during treatment the label requires - (a) TPMT testing - (b) pulmonary function only - (c) audiometry - (d) evaluation of left ventricular function **Answer: (d)** — Boxed cardiomyopathy; ICMR gives trastuzumab for 12 months. **Q14.** ICMR's duration of adjuvant trastuzumab for HER2-positive breast cancer is - (a) 12 months - (b) lifelong - (c) 2 weeks - (d) 5 years **Answer: (a)** — ICMR breast cancer workflow (shorter 9-week to 6-month schedules acceptable in some). **Q15.** A premenopausal woman with ER-positive breast cancer finishes surgery. ICMR's hormonal therapy is - (a) trastuzumab - (b) tamoxifen (minimum 5 years) - (c) an aromatase inhibitor alone - (d) no hormonal therapy **Answer: (b)** — Postmenopausal: tamoxifen or an aromatase inhibitor. **Q16.** Before rituximab for lymphoma, a patient with past hepatitis B must be monitored because the boxed warning includes - (a) QT prolongation - (b) gingival hyperplasia - (c) lactic acidosis - (d) HBV reactivation (and PML) **Answer: (d)** — Rituxan Hycela label. **Q17.** A kidney-transplant patient on tacrolimus develops high blood sugar. The label calls this - (a) steroid diabetes only - (b) new-onset diabetes after transplant - (c) unrelated - (d) type 1 diabetes **Answer: (b)** — Also nephrotoxicity; boxed malignancy and infection. **Q18.** A transplant patient on cyclosporine has swollen gums, excess hair growth, tremor and high BP. These are - (a) principal cyclosporine adverse effects - (b) signs of rejection - (c) unrelated - (d) tacrolimus effects **Answer: (a)** — Renal dysfunction, tremor, hirsutism, hypertension, gum hyperplasia. **Q19.** A young woman with lupus nephritis is offered mycophenolate. She must be counselled about - (a) hypokalaemia - (b) ototoxicity - (c) gum hyperplasia - (d) first-trimester pregnancy loss and malformations (boxed) **Answer: (d)** — Pregnancy prevention is required. **Q20.** A man on azathioprine is started on allopurinol for gout and develops severe marrow suppression. The reason is - (a) coincidence - (b) allopurinol blocks xanthine oxidase, a pathway that inactivates azathioprine's metabolite - (c) gout causes marrow failure - (d) allopurinol is myelotoxic alone **Answer: (b)** — Azathioprine is inactivated by TPMT and by xanthine oxidase; reduce the dose with allopurinol. **Q21.** A child with ALL on 6-mercaptopurine needs allopurinol. The label says reduce 6-MP to - (a) no change - (b) half - (c) one-third to one-quarter of the dose - (d) double **Answer: (c)** — Mercaptopurine label. **Q22.** A child on 6-MP has repeated severe myelosuppression. The label suggests checking - (a) TPMT and NUDT15 status - (b) HLA-B*5701 - (c) DPYD - (d) G6PD **Answer: (a)** — Genetic variants reduce inactivation. **Q23.** Doxorubicin leaks out of the vein during infusion. The boxed warning mentions - (a) no local effect - (b) only allergy - (c) extravasation and tissue necrosis - (d) hyperglycaemia **Answer: (c)** — Doxorubicin boxed warning. **Q24.** Leucovorin works as an antidote because it - (a) bypasses folic acid antagonism - (b) chelates methotrexate - (c) blocks DHFR - (d) increases renal excretion only **Answer: (a)** — Folinic acid; antidote to folic acid antagonists. ### Active Recall From memory: give the signature toxicity and rescue or prevention for methotrexate, cyclophosphamide, doxorubicin, cisplatin, vincristine, bleomycin and 5-FU; the target and warning for imatinib, trastuzumab and rituximab; ICMR's breast cancer hormonal and HER2 plan; and the key warnings for tacrolimus, cyclosporine, mycophenolate, azathioprine and 6-MP.