Product Information
Registration Status: ActivePURINETONE TABLET 50mg is approved to be sold in Singapore with effective from 1999-03-17. It is marketed by SHOEI UNIVERSAL CORPORATION PTE LTD, with the registration number of SIN10810P.
This product contains Mercaptopurine 50mg in the form of TABLET. It is approved for ORAL use.
This product is manufactured by KOREA UNITED PHARMACEUTICAL INC in KOREA, and in REPUBLIC OF.
It is a Prescription Only Medicine that can only be obtained from a doctor or a dentist, or a pharmacist with a prescription from a Singapore-registered doctor or dentist.
Description
An antimetabolite antineoplastic agent with immunosuppressant properties. It interferes with nucleic acid synthesis by inhibiting purine metabolism and is used, usually in combination with other drugs, in the treatment of or in remission maintenance programs for leukemia. [PubChem]
Indication
For remission induction and maintenance therapy of acute lymphatic leukemia.
Mechanism of Action
Mercaptopurine competes with hypoxanthine and guanine for the enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRTase) and is itself converted to thioinosinic acid (TIMP). This intracellular nucleotide inhibits several reactions involving inosinic acid (IMP), including the conversion of IMP to xanthylic acid (XMP) and the conversion of IMP to adenylic acid (AMP) via adenylosuccinate (SAMP). In addition, 6-methylthioinosinate (MTIMP) is formed by the methylation of TIMP. Both TIMP and MTIMP have been reported to inhibit glutamine-5-phosphoribosylpyrophosphate amidotransferase, the first enzyme unique to the de novo pathway for purine ribonucleotide synthesis. Experiments indicate that radiolabeled mercaptopurine may be recovered from the DNA in the form of deoxythioguanosine. Some mercaptopurine is converted to nucleotide derivatives of 6-thioguanine (6-TG) by the sequential actions of inosinate (IMP) dehydrogenase and xanthylate (XMP) aminase, converting TIMP to thioguanylic acid (TGMP).
Pharmacokinetics
- Absorption
- Clinical studies have shown that the absorption of an oral dose of mercaptopurine in humans is incomplete and variable, averaging approximately 50% of the administered dose. The factors influencing absorption are unknown.
- Distribution
- The volume of distribution exceeded that of the total body water.
- Metabolism
- Hepatic. Degradation primarily by xanthine oxidase. The catabolism of mercaptopurine and its metabolites is complex. In humans, after oral administration of 35S-6-mercaptopurine, urine contains intact mercaptopurine, thiouric acid (formed by direct oxidation by xanthine oxidase, probably via 6-mercapto-8-hydroxypurine), and a number of 6-methylated thiopurines. The methylthiopurines yield appreciable amounts of inorganic sulfate.
- Elimination
Toxicity
Signs and symptoms of overdosage may be immediate such as anorexia, nausea, vomiting, and diarrhea; or delayed such as myelosuppression, liver dysfunction, and gastroenteritis. The oral LD50 of mercaptopurine was determined to be 480 mg/kg in the mouse and 425 mg/kg in the rat.
Active Ingredient/Synonyms
6 MP | 6-Mercaptopurine | 6-MP | 6-Thiohypoxanthine | 6-Thioxopurine | Mercaptopurina | Mercaptopurine anhydrous | mercaptopurinum | Mercapurin | Mercaptopurine |
Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.