Mercaptopurine

What is this medication?

6-Mercaptopurine, Purinethol/Purixan
Antineoplastic; Antimetabolite; Immunosuppressant

Officially indicated for use in acute lymphoblastic leukemia.  It is also prescribed off-label for use in acute promyelocytic leukemia, Crohn disease, lymphoblastic lymphoma, and ulcerative colitis.

How does this medication work?

Mercaptopurine is a purine antagonist and blocks the incorporation of purine nucleotides into DNA and RNA essentially inhibiting their synthesis.

How should I take this medication?

Acute, lymphoblastic leukemia
Oral: Take 1.5mg/kg to 2.5mg/kg once daily

How to Take: Take on an empty stomach at the same time each day. 

What should I watch for while using this medication?

Bone marrow suppression 

Risk of hematologic toxicity in patients with hepatic impairment

Can cause infections, macrophage activation syndrome, malignancy

Can cause photosensitivity

Use with caution in patients with hepatic and renal impairment

What if I miss a dose?

If you miss a dose of medication, try to take it as soon as possible.  However, if it is almost time for your next dose, take only that scheduled dose.  Do not take double or extra doses.

How should I store this medication?

Keep out of the reach of children at all times.  Store at room temperature, 59 to 86° F (15 to 30° C).  Protect from light.  Keep the container tightly closed.  Properly dispose of any unused medication after the expiration date.

What are the possible side effects of using this medication?

The frequency of side effects is not defined but do include:

Malaise, drug fever, skin rash, hyperpigmentation, urticaria , alopecia, hyperuricemia, anorexia, diarrhea, nausea, vomiting, oral lesion, pancreatitis, cholestasis, mucositis, sprue-like symptoms, stomach pain, ulcerative bowel lesion, oligospermia, renal toxicity, uricosuria, bone marrow depression, anemia, granulocytopenia, hemorrhage, hepatosplenic T-cell lymphomas, leukopenia, lymphocytopenia, metastases, neutropenia, thrombocytopenia, hyperbilirubinemia, increased serum transaminases, ascites, hepatic encephalopathy, hepatic fibrosis, hepatic injury, hepatic necrosis, hepatomegaly, hepatotoxicity, intrahepatic cholestasis, jaundice, toxic hepatitis, immunosuppression, infection, pulmonary fibrosis.