Chemotherapy Flashcards
How do antimetabolites work?
Inhibit DNA synthesis.
Give 3 examples of antimetabolites
Methotrexate, fluorouracil and mercaptopurine.
What is methotrexate?
A folic acid antagonist.
What is fluorouracil?
A pyramidine analogue.
What is mercaptopurine?
An inhibitor of purine synthesis.
What are alkylating agents?
Drugs forming alkyl group bonds to nucleic acids, causing DNA strand cross linking and preventing replication.
Name 2 alkylating agents
Cyclophosphamide and melphalam
Name an intercalating agent?
Dactinomycin
How do intercalating agents work?
Intercalates between base pairs, inhibiting RNA synthesis and subsequently preventing cell division.
How do spindle poisons work?
They bind to tubulin and inhibit polymerisation of microtubules preventing mitotic spindle formation, and prevents mitosis.
Name 3 examples of spindle poisins
Vinca alkaloids, vincristine and vinblastine
What cancers are highly sensitive to chemotherapy?
Lymphoma, Wilm’s, germ cell cancers, small cell lung carcinoma, neuroblastoma
What cancers are only moderately sensitive to chemotherapy?
Breast, colorectal, bladder, ovarian and cervix.
What cancers aren’t very responsive to chemotherapy?
Prostate, renal cell, brain and endometrial.
What are some common ADRs to chemotherapy?
Vomiting (acute phase (4-12hrs), delayed onset (2-5 days later) and chronic phase (2 weeks)), alopecia (2/3 weeks- very common with vinca alkaloids and cyclophosphamide), skin toxicity (irritation and hyperpigmentation in cyclophosphamide), mucositis, cardiomyopathy, arrythmia, haematological toxicity (low neutrophils and platelets.
What effect does vomiting or mucositis have on chemotherapy?
Worsens absorption of drugs.
What effect does weight loss have on chemotherapy?
Lowers distribution.
What are some DDIs of methotrexate?
Penicillins and NSAIDs.
What is a DDI of vincristine?
Causes neuropathy if combined with itraconazole (anti-fungal).
What is a DDI of capecitabine (antimetabolite)?
Warfarin and any CYP450 inhibtors.
What monitoring must be done in chemotherapy?
Monitoring of cancer response through relevant imaging or tumour marker blood tests, testing blood drug levels, and looking for any organ toxicity (ECG, creatinine levels etc.).
