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Purixan (MERCAPTOPURINE)

Stason Pharms · FDA-approved approved Small molecule Quality 62/100

Purixan works by inhibiting the enzyme responsible for producing prostaglandins, which are involved in inflammation and immune response.

Purixan (Mercaptopurine) is a small molecule drug developed by Stason Pharms, targeting Prostaglandin G/H synthase 1. It is a member of the mercaptopurine class and was first approved by the FDA in 1953 for the treatment of Acute lymphoid leukemia, Acute promyelocytic leukemia, and FAB M3. Purixan is off-patent and has multiple generic manufacturers. Key safety considerations include its short half-life of 1.0 hours and low bioavailability of 12%. As an off-patent medication, its commercial status is primarily generic.

At a glance

Generic nameMERCAPTOPURINE
SponsorStason Pharms
Drug classmercaptopurine
TargetProstaglandin G/H synthase 1
ModalitySmall molecule
Therapeutic areaOncology
PhaseFDA-approved
First approval1953

Mechanism of action

Mechanism of Action: Mercaptopurine (6-MP) 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 action of inosinate (IMP) dehydrogenase and xanthylate (XMP) aminase, convert

Approved indications

Common side effects

Drug interactions

Key clinical trials

Primary sources

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SourceUsed for
FDA labelMechanism, indications, dosing, boxed warnings, drug interactions
ClinicalTrials.govTrial enrolment, design, endpoints, results

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