The key difference between Azathioprine and 6-mercaptopurine is that Azathioprine works by inhibiting purine synthesis, whereas 6-mercaptopurine works by interfering with normal metabolic processes within cells to disrupt DNA and RNA synthesis.
Azathioprine is an immunosuppressive medication sold under the brand name Imuran while 6-mercaptopurine is a medication useful in treating cancers and autoimmune diseases.
CONTENTS
1. Overview and Key Difference
2. What is Azathioprine
3. What is 6-Mercaptopurine
4. Azathioprine vs 6-Mercaptopurine in Tabular Form
5. Summary – Azathioprine vs 6-Mercaptopurine
What is Azathioprine?
Azathioprine is an immunosuppressive medication sold under the brand name Imuran. It is abbreviated as AZA. This medication can be used to treat rheumatoid arthritis, granulomatosis with polyangiitis, Crohn’s disease, ulcerative colitis and systemic lupus erythematosus, kidney transplants for prevention of rejections. This medication is taken orally or as an injection into the vein.
Figure 01: The Chemical Structure of Azathioprine
There can be some side effects of Azathioprine: bone-marrow suppression and vomiting. However, bone-marrow suppression is common in people having genetic deficiency of the enzyme thiopurine S-methyltransferase. There can be some serious effects as well, such as cancers. If taken during pregnancy, it can harm the baby.
The bioavailability of Azathioprine is about 60%. However, the bioavailability ranges between 30 to 90% in patients. This is because this drug is partly inactivated in the liver. The protein binding ability of this medication is around 20 – 30%. Its metabolism occurs activated non-enzymatically and deactivated by xanthine oxidase. The elimination half-life of Azathioprine is about 26 – 80 hours. The excretion of the medication occurs through the kidney.
When considering the mechanism of action of this medication, it can inhibit purine synthesis. Usually, purine is required to produce DNA and RNA. Therefore, inhibition of purine can cause reduced production of DNA and RNA, which is required for the production of white blood cells. This, in turn, causes immunosuppression.
What is 6-Mercaptopurine?
6-mercaptopurine is a medication useful in treating cancers and autoimmune diseases. This medication is sold under the brand name Purinethol. Most importantly, 6-mercaptopurine is useful in treating acute lymphocytic leukemia, chronic leukemia, and ulcerative colitis.
Figure 02: The Chemical Structure of 6-Mercaptopurine
There can be some common side effects such as bone marrow suppression, liver toxicity, vomiting, and loss of appetite. However, there can be some serious side effects as well, such as cancers and pancreatitis. Moreover, the use of this drug during pregnancy can cause harmful effects on the baby.
The bioavailability of 6-mercaptopurine can range between 5 – 37%. Metabolism of this drug occurs in the presence of xanthine oxidase. The elimination half-life of this drug is about 60 to 120 minutes. The excretion occurs in the kidney.
What is the Difference Between Azathioprine and 6-Mercaptopurine?
Azathioprine is an immunosuppressive medication sold under the brand name Imuran while 6-mercaptopurine is a medication useful in treating cancers and autoimmune diseases. The key difference between Azathioprine and 6-mercaptopurine is that Azathioprine works by inhibiting purine synthesis, whereas 6-mercaptopurine works by interfering with normal metabolic processes within cells to disrupt DNA and RNA synthesis. Moreover, bone-marrow suppression and vomiting are the side effects of Azathioprine while marrow suppression, liver toxicity, vomiting, and loss of appetite are some side effects of 6-mercaptopurine.
The below infographic presents the differences between Azathioprine and 6-mercaptopurine in tabular form for side by side comparison.
Summary – Azathioprine vs 6-Mercaptopurine
Azathioprine and 6-mercaptopurine are important medications to treat cancers and related diseases. The key difference between Azathioprine and 6-mercaptopurine is that Azathioprine works by inhibiting purine synthesis, whereas 6-mercaptopurine works by interfering with normal metabolic processes within cells to disrupt DNA and RNA synthesis.
Reference:
1. “6-MP.” Chemocare, Cleveland Clinic.
Image Courtesy:
1. “Azathioprine” By Ayacop – PubChem (Public Domain) via Commons Wikimedia
2. “Mercaptopurine” By Fvasconcellos – Own work (Public Domain) via Commons Wikimedia