The tables below summarises the mechanism of action and major adverse effects of commonly used cytotoxic agents.

Alkylating agents

Cytotoxic Mechanism of action Adverse effects
Cyclophosphamide Alkylating agent - causes cross-linking in DNA Haemorrhagic cystitis, myelosuppression, transitional cell carcinoma

Cytotoxic antibiotics

Cytotoxic Mechanism of action Adverse effects
Bleomycin Degrades preformed DNA Lung fibrosis
Anthracyclines (e.g doxorubicin) Stabilizes DNA-topoisomerase II complex inhibits DNA & RNA synthesis Cardiomyopathy

Antimetabolites

Cytotoxic Mechanism of action Adverse effects
Methotrexate Inhibits dihydrofolate reductase and thymidylate synthesis Myelosuppression, mucositis, liver fibrosis, lung fibrosis
Fluorouracil (5-FU) Pyrimidine analogue inducing cell cycle arrest and apoptosis by blocking thymidylate synthase (works during S phase) Myelosuppression, mucositis, dermatitis
6-mercaptopurine Purine analogue that is activated by HGPRTase, decreasing purine synthesis Myelosuppression
Cytarabine Pyrimidine antagonist. Interferes with DNA synthesis specifically at the S-phase of the cell cycle and inhibits DNA polymerase Myelosuppression, ataxia

Acts on microtubules

Cytotoxic Mechanism of action Adverse effects
Vincristine, vinblastine Inhibits formation of microtubules Vincristine: Peripheral neuropathy (reversible) , paralytic ileusVinblastine: myelosuppression
Docetaxel Prevents microtubule depolymerisation & disassembly, decreasing free tubulin Neutropaenia

Topoisomerase Inhibitors

Cytotoxic Mechanism of action Adverse effects
Irinotecan Inhibits topoisomerase I which prevents relaxation of supercoiled DNA Myelosuppression

Other cytotoxic drugs

Cytotoxic Mechanism of action Adverse effects
Cisplatin Causes cross-linking in DNA Nephrotoxicity (the primary dose-limiting side effect), Ototoxicity, peripheral neuropathy, hypomagnesaemia
Hydroxyurea (hydroxycarbamide) Inhibits ribonucleotide reductase, decreasing DNA synthesis Myelosuppression

Methotrexate

Azathioprine