Proceedings of AVA Annual Conference, Brisbane, 2018. Dandrieux, J – Immune suppressive drugs: Do we need more than prednisolone? Immune suppressive drugs: Do we need more than prednisolone? Julien Dandrieux U-Vet Werribee Animal Hospital 250 Princes Hwy, Werribee VIC 3030 Introduction Prednisolone is a very effective immune suppressive drug, with rapid onset of action at an attractive price. However, the effect of corticosteroids is not specific to the immune system and for this reason several adverse effects can be seen. This is especially an important consideration when treating diseases for which immune suppression is expected to be needed for several months to achieve a durable clinical response. For this reason, several other immune suppressive drugs have been used commonly in conjunction with steroids such as azathioprine, cyclosporine, and chlorambucil as steroid sparing drugs. Chlorambucil and cyclosporine can also be used as sole agent in animals where prednisolone is contra-indicated: for example, to treat a cat that has developed diabetes while treated with steroids. We will get more familiar with newer immune suppressive drugs such as mycophenolate and leflunomide. At the end of this discussion, you should feel comfortable to use these drugs in your busy every day caseload. Some common drugs dosages are listed in table 1. However, these should be used as guidelines only as the exact dosage can vary greatly depending on the individual animal and the condition treated. Animals on any immune-suppressive drugs should be monitored both for control of their disease (to ensure improvement with the treatment) and for secondary infections. Commonly used immunosuppressive drugs Glucocorticoids such as prednisolone are often used as the first line treatment as their onset of effect is very rapid and they are relatively cheap. However, they cause many side effects that can be a worry for the owner - such as polydipsia (PD), polyuria (PU), polyphagia (PP), and lethargy. Budesonide is a corticosteroid with local effect in the gut which can be used for steroid-responsive diarrhoea with less systemic side effects than other steroids. However, some absorption and systemic side effects are also seen with this drug. Because steroids have many side effects, which are not only dose dependent but also time dependent (low doses of prednisolone over time can have as much side effect as a high dose for a short period), they are often combined with other immunosuppressive agents to enable a faster decrease in the steroid dosage. Azathioprine is commonly used to this effect in dogs and chlorambucil in cats. Other drugs will be used as single agents or combined agents depending on the disease and veterinarian preference. There is currently very little literature to support one type of immune-suppressive drugs over the other and it becomes a clinician’s preference. Cyclosporine is frequently used especially in dermatological conditions. Leflunomide and mycophenolate are seldom used as a first-line treatment, but rather