Anyone using Imuran as a supplement to reducing prednisone? What have you found for side effects

The drug you mentioned is used for treating a number of things. 

In your case could it be rheumatoid arthritis ?

Having never heard of this drug I Googled it and it is an immunosuppressant too. I don't know why you would be given this and prednisone but looking forward to reading other people's posts on this medication. I wonder how it differs from prednisone.

The thinking behind using azathioprine and other DMARDs such as leflunomide or methotrexate is that they add to the immunosuppressive effect and allow the same effect to be achieved with a lower dose of pred. There is little study evidence that this is achieved reliably but there are rheumies who claim they have worked well for them - at least, each rheumy seems to have their favoured drug to use in this way. 

I suspect that often when they work it is because it wasn't PMR in the first place but some form of inflammatory arthritis - where they would be the first line choice anyway. About 1 in 6 patients with an initial diagnosis of PMR go on to be given a different diagnosis at some later stage.

In the most recent recommendations for the treatment of PMR

https://www.rheumatology.org/Portals/0/Files/2015%20PMR%20guidelines.pdf

they discuss this in Recommendation 7. They feel methotrexate is worth a try on an individual basis and IN DISCUSSION WITH THE PATIENT. No other DMARDs get a mention, including azathioprine/Imuran. I have tried methotrexate - after 4 weeks I felt worse than I ever did with untreated PMR! The fatigue was overwhelming - the other side effects were unpleasant but none really bad enough to say no - but all together they were. I did it to humour my new rheumy - but I can't live like that even if it did get me to a few mg lower. I think it is perhaps worth a try if you don't develop any side effects and, to be fair, many people take it perfectly happily. But, nevertheless, about a third of patients stop mtx because of the side effects. Perhaps the same should apply to azathioprine - but it seems less successful.

In 2015 I was prescribed Azathioprine 50mgms tablet daily.  This was to be increased to 1 and a half tablets after 28 days to treat my PMR alongside the prednisolone I was taking at that time.  On the 11th day I developed a very high temperature, vomiting , diarrhoea and confusion  - advised to stop Azathiorine immediately and a couple of days later I was ok.  6 weeks later it was decided to trial me again in case I had a viral infection at the time of the first trial. After a few days into the trial the same symptoms recurred - end of trial.  I am currently on 5mgms prednisolone daily.