The use of Ribavirin to treat chronic hepatitis C in patients receiving azathioprine has been reported to induce severe pancytopenia and may increase the risk of azathioprine-related myelotoxicity. Inosine monophosphate dehydrogenase (IMDH) is required for one of the metabolic pathways of azathioprine.
There are several common underlying causes of kidney disease. 1  In older cats Interstitial Nephritis is most frequently seen. 2  Polycystic Kidney Disease (PKD) is a very common problem in Persian cats - 20-30% of them can be affected. 3  Tumours are occasionally seen in middle-aged and older cats.
1. Hyperthyroidism (overactive thyroid glands). This hormonal disease is common in older cats. Hyperthyroid cats are usually hypertensive (have high blood pressure), and this results in increased blood flow through the kidneys. As mentioned above, extra blood flow helps the aging kidney maintain function.