Azathioprine

Methotrexate

Ciclosporin

Cell Cycle

Colchicine also inhibits microtubules

SEs include Bone marrow suppression, hemolysis, pulmonary toxicity, neurotoxicity, leukemogenic

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

Master mnemonic: “DNA → Tubes → Folate → Free Radicals → Topo → Misc”

A. Alkylating agents (cell cycle non-specific)

Cytotoxic Mechanism of action Adverse effects
Cyclophosphamide Alkylating agent - causes cross-linking in DNA Haemorrhagic cystitis,
myelosuppression, transitional cell carcinoma
Tx - Mesna (traps toxic component acrolein)
Busulfan pulmonary fibrosis (“bus‑ulfan = bus‑lungs”)
Melphlan Alkylating agent - formation of cross-links → prevent DNA replication and transcription

Cyclophosphamide causes hemorrhagic cystitis and bladder cancer by producing a bladder-toxic metabolite called acrolein.

Procarbazine (alkylating agent) - used in Hodgkin's lymphoma

Nitrosoureas (Lomustine, Carmustine) - cross BBB and good for brain tumors