902. Azathioprine

Nomenclature

CAS number: 446-86-6
6-[(1-Methyl-4-nitro-1H-imidazol-5-yl)thio]-1H-purine; 6-(1-methyl-4-nitro-5-imidazolyl)mercaptopurine; azothioprine; BW-57-322; NSC-39084; Azanin (Tanabe); Azarek (Ecosol); Azasan (Salix); Imuran (GSK); Imurek (GSK); Imurel (GSK); Zytrim (Merckle).
C9H7N7O2S; mol wt 277.26.
C 38.99%, H 2.54%, N 35.36%, O 11.54%, S 11.56%.

Description and references

Immunosuppressive antimetabolite; also active as disease modifying antirheumatic drug (DMARD). Metabolized in vivo to 6-mercaptopurine, q.v. Prepn: G. H. Hitchings, G. B. Elion, US 3056785 (1962 to Burroughs Wellcome). Metabolism and pharmacokinetics: T. L. Ding, L. Z. Benet, Drug Metab. Dispos. 7, 373 (1979). Carcinogenicity studies: P. S. Mitrou et al., Arzneim.-Forsch. 29, 483, 662 (1979). HPLC determn in plasma: E. C. Van Os et al., J. Chromatogr. B 679, 147 (1996). Clinical trial in rheumatoid arthritis: R. F. Wilkens, D. Stablein, J. Rheumatol. 23, Suppl. 44, 64 (1996). Comprehensive description: W. P. Wilson, S. A. Benezra, Anal. Profiles Drug Subs. 10, 29-53 (1981). Review of clinical efficacy in renal transplantation: G. L. C. Chan et al., Pharmacotherapy 7, 165-177 (1987); in multiple sclerosis: C. Confavreux, T. Moreau, Mult. Scler. 1, 379-384 (1996); in inflammatory bowel disease: W. J. Sandborn, Scand. J. Gastroenterol. 33, Suppl. 225, 92-99 (1998).

Chemical structure

Properties

Pale yellow crystals from 50% aq acetone, dec 243-244°. uv max (methanol): 276 nm (ε 1.82 × 104); (0.1N HCl): 280 nm (ε 1.73 × 104); (0.1N NaOH): 285 nm (ε 1.55 × 104). pKa2 8.2. Slightly sol in chloroform, ethanol. Practically insol in water.

Derivative

Sodium salt.

Nomenclature

CAS number: 55774-33-9
C9H6N7NaO2S; mol wt 299.24.
C 36.12%, H 2.02%, N 32.77%, Na 7.68%, O 10.69%, S 10.72%.

Properties

Soly in water: 10 mg/ml.

Caution

Azathioprine is listed as a known human carcinogen: Report on Carcinogens, Eleventh Edition (PB2005-104914, 2004) p III-25.

Therapeutic Category

Immunosuppressant; antirheumatic.

Therapeutic Category (Veterinary)

Immunosuppressant.

Keywords

Antiarthritic/Antirheumatic; Immunosuppressant