ALKYLATING AGENTS are so named because Ihey alkylate or chemically react with certain biochemical entities, particularly those concerned with the synthesis of nucleic acid. Alkylulion is the substitution of an organic grouping in place of another grouping in a niolecule.
Alkylating agents are are important because they interfere with the growth and reproduction of cells, disrupting the replication of cells. This cytotoxic property is used to retard the division and growth of cancer cells, and the alkylating drugs are widely'used in the chemotherapy of rnalignant tumours, often in conjunction with surgery and sometimes with radiotherapy. Unfortunately, troublesome side-effects occur such as: damage to veins when the drug is given intravenously with resultant leakage into adjacent tissues; impaired kidney function by the formation of uric acid crystals; nausea and vomiting; alopecia (hair loss); suppression of bone marrow activity (production of blood cells); adverse effects on reproductive function, including teratogenesis. Indeed, cytotoxic drugs must not be given in pregnancy, especially during the first three months, Prolonged use of alkylating drugs, especially when accompanying radiotherapy, is also associated with a signficant rise in the incidence of acute non-lymphocytic leukaemia. Among the dozen or so alkylating drugs in use are carmustine,