What Is Azathioprine?

Azathioprine (Imuran®) is a prescription medication that is approved to: 

• Be used along with other medications to prevent organ rejection after a kidney transplant 
• Reduce  the signs and symptoms  of active rheumatoid arthritis. 

Who Makes It? 

Azathioprine  is made by Prometheus Laboratories. 
 
How Does Azathioprine Work? 

It  is not known exactly how azathioprine works  to prevent kidney transplant  rejection or  to treat rheumatoid arthritis. The medication acts  in a way similar to certain types  of chemotherapy medications, killing cells  by damaging DNA. Also, much like chemotherapy medications, azathioprine suppresses  the immune system (it is thought to work mostly by suppressing  the immune system). The immune system is responsible for rejecting  transplanted organs, and an overactive immune system plays an important role in rheumatoid arthritis.
  
When and How to Take It 

General considerations for when and how to take azathioprine include the following: 
 

• The medication  comes in  tablet form.  It is usually taken by mouth  once or twice a day. 
• You can  take azathioprine with or without food. If the medication bothers your stomach, try taking  it with food. 
• Azathioprine should be taken at  the same time(s) each day  to maintain an even level in  your blood.
• For the medication  to work properly, it must be taken  as prescribed.  Azathioprine will  not work  if you stop taking it. 

Dosing Information 

The dose of azathioprine your healthcare provider recommends will vary, depending on a number of factors, including: 

• The medical  condition being treated 
• How  your body responds to  the drug (some people do not clear it from the body as well as others) 
• Your weight 
• Other medical  conditions you may have 

As is always the case, do not adjust your dose unless your healthcare provider specifically instructs you to do so. 

Azathioprine Side Effects 

As with any medicine, side effects are possible with azathioprine. However, not everyone who takes  the drug will experience side effects. In fact, most people tolerate  it quite well. If side effects do occur, in most cases, they are minor  and either require no treatment  or can easily be treated by you or  your healthcare provider. Serious side effects are less common. 
 
Common side effects include but are not limited to: 

• Leukopenia (low levels  of certain white blood cells called leukocytes) 
• Infections
• Nausea  
• Vomiting.

Drug Interactions 

Azathioprine can potentially interact with a few medicines 

What Should I Tell My Healthcare Provider Before Taking Azathioprine? 

You should talk with your healthcare provider prior to taking this drug if you have: 

• Taken chemotherapy medications in the past 
• A blood disorder 
• Any infection. 

Also, let your healthcare provider know if you are: 

• Pregnant or thinking of becoming pregnant 
• Breastfeeding

Make sure  to tell your healthcare provider about all of the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements.
  
What If I Take an Overdose? 

People who  take too much azathioprine may  have overdose symptoms that could include: 

• Bone marrow depression (a decreased ability of the bone marrow to make blood cells) 
• Bleeding
• Infections
• Nausea, vomiting, and diarrhea 
• Loss of life. 

If you happen to take too much, seek immediate medical attention.
  
How Should Azathioprine Be Stored? 

Azathioprine should be stored at room temperature, away from moisture and heat. The tablets should be stored in an airtight container.
 
Keep this and all medications out of the reach of children. 

What Should I Do If I Miss a Dose? 

If you do not take your azathioprine as scheduled, take your missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule. Do not take a double dose.
  
Available Strengths 

Azathioprine tablets are available in one strength -- Azathioprine 50 mg. An injectable form is also available.
  
Generic Azathioprine 

Currently, both brand-name and generic versions of azathioprine are licensed for sale