ABSTRACT
Novalgin; the sodium sulphonate derivative of aminopyrine, is an analgesic, antipyretic drug, widely used in Egypt. In spite of its well known hematologic complications, mutagenicity tests are deficient in the literature. The main aim of the present work was to study the cytogenetic effects of novalgin on bone marrow cells of Rattus norvegicus, using the method recommended by the Ad Hoc Committee of Mutagenicity Testing [1972]; Novalgin induced significant Chromosomal aberrations of both chromatid and chromosome type, and depression of mitosis 48 hours after treatment with the maximum tolerated dose in the acute study and after sub-acute treatment with the clinical dose, The results of the study suggest that novalgin is mutagenic and causes depression of mitosis when administered at very high doses, or after prolonged use of the clinical dose