Chemotherapy mechanisms of action and side effects

Question 1

Mechanism of action of alkylating agents?

Answer 1

Cross link guanine nucleobases in DNA

PLATINUM analogues - carboplatin, cisplatin, oxaliplatin

Question 2

Mechanism of action of Antimetabolites?

Answer 2

Inhibit DNA synthesis

Folate inhibitors - MTX, pemetrexed
Purine analogues - mercaptopurine
Pyrimidine analogues - 5-FU, capcetabine, gemcetabine
Hydroxyurea

Question 3

Mechanism of action of Topoisomerase II inhibitors?

Answer 3

Block topoisomerase action = Unwinding DNA

Anthracyclines - doxorubicin
Epipodophyllotoxins - Etoposide

Question 4

Mechanism of antimicrotubule agents?

Answer 4

Inhibit microtubule action

Taxanes - paclitaxel, docetaxel
Vinca alkaloids - vinblastine

Question 5

Mechanism of action of anti-tumour antibiotics

Answer 5

Induce DNA lesions, inhibit topoisomerases

Bleomycin

Question 6

Side effects of cisplatin?

Answer 6

Acoustic nerve damage

Nephrotoxicity

Question 7

Side effect of Taxanes and vinca alkaloids?

Answer 7

Peripheral neuropathy

Question 8

Side effect of bleomycin?

Answer 8

Pulmonary fibrosis

Question 9

Side effects of doxorubicin?

Answer 9

Non reversible cardiomyopathy
Lymphoma
Alopecia

Question 10

Side effect of cyclophosphomide?

Answer 10

Haemorrhagic cystitis

Question 11

Side effect of tamoxifen?

Answer 11

Cataracts

Question 12

Causes of hypercalcaemia in oncology patients?

Answer 12

PTHrP - tumour cells secreting PTH related protein - squamous cell, renal cell, breast and ovarian cancer

Osteolytic
Rarely calciteriol producing - Hodgkins

Question 13

Treatment of hypercalcaemia?

Answer 13

Fluids and rehydration

–> IV bisphosphonate

Question 14

Side effects of Pyrimidine analogues?

Answer 14

Coronary vasospasm
Diarrhoea
Mucositis
Hand and foot erythema

DPD deficiency = worse SEs

Question 15

Side effects of Oxaliplatin?

Answer 15

Peripheral neuropathy
Diarrhoea
Myelosuppression
Cold induced laryngospasm
Neurotoxicity