starting dosages in dogs are 2-4 mg/kg once a day. In cats we use 2mg/kg once a day (10mg/cat on average) for several days and then usually decrease to every other day. The drug reaches steady state fairly rapidly in about 4 days. Ideally a trough blood serum level (22-24 hours post pilling) should be measured about 10-14 days after starting and dosage adjustments may be made based on these values and the patient's clinical response.
The drug is generally very well tolerated, but side effects include deceased appetite, vomiting, and diarrhea. Decreases in leukocytes, red cells and platelets can be seen. Possibly the most common side effect seen in dogs is a rapidly developing cutaneous, ulcerative drug eruption. This drug eruption is frequently seen on the nasal plane, face or food pads, but on occasion will occur on the neck or truncal skin. This drug eruption rapidly resolves if Leflunomide therapy is discontinued. In people, acute hepatic necrosis has been reported, and although this has not been reported in dogs, there have been suspected cases that can present similar to that of imuran toxicity. For these reasons, a CBC should be monitored monthly, as well as intermittent liver panels.
Keep away from children and animals. Leflunomide should not be given to pregnant animals or animals with severe kidney failure.
Side effects of Leflunomide may include : decreased appetite, tiredness or vomiting.
Store at 25°C (77°F); excursions permitted to 15° to 30°C (59° to 86°F) [see USP Controlled Room Temperature]. Protect from light.