Mercaptopurine (3 brand names, 2 dosage forms, 1 route)
Available dosage forms: TABLET, SUSPENSION.
Routes of administration: ORAL.
Brand Names
- MERCAPTOPURINE
- PURINETHOL
- PURIXAN
Contraindications
None.
Adverse Reactions
The following clinically significant adverse reactions are described elsewhere in the labeling: •Myelosuppression [see Warnings and Precautions (5.1)] •Hepatotoxicity [see Warnings and Precautions (5.2)] •Immunosuppression [see Warnings and Precautions (5.3)] •Treatment Related Malignancies [see Warnings and Precautions (5.4)] •Macrophage Activation Syndrome [see Warnings and Precautions (5.5)]
Mechanism of Action
Mercaptopurine is a purine analog that undergoes intracellular transport and activation to form metabolites including thioguanine nucleotides (TGNs). Incorporation of TGNs into DNA or RNA results in cell-cycle arrest and cell death. TGNs and other mercaptopurine metabolites are also inhibitors of de novo purine synthesis and purine nucleotide interconversions. Mercaptopurine was cytotoxic to proliferating cancer cells in vitro and had antitumor activity in mouse tumor models. It is not known which of the biochemical effects of mercaptopurine and its metabolites are directly or predominantly responsible for cell death.
Overdosage
Signs and symptoms of mercaptopurine overdosage may be immediate (anorexia, nausea, vomiting, and diarrhea) or delayed (myelosuppression, liver dysfunction, and gastroenteritis). Dialysis cannot be expected to clear mercaptopurine. Hemodialysis is thought to be of marginal use due to the rapid intracellular incorporation of mercaptopurine into active metabolites with long persistence. Withhold mercaptopurine immediately if severe or life-threatening adverse reactions occur during treatment. If a patient is seen immediately following an accidental overdosage, it may be useful to induce emesis.