Cyclosporine can cause some side effects. About 25% of people taking cyclosporine develop high blood pressure (hypertension). In addition, because cyclosporine can be tough on the kidneys, it can cause a substance called uric acid to build up in the blood (a state known as hyperuricemia). Sometimes this buildup of uric acid can cause gout, a condition that causes intense swelling in one of the joints, often the the big toe. If you already have gout, your condition may worsen while taking cyclosporine. Fortunately, many of these side effects go away as treatment with cyclosporine is reduced or stopped, so your doctor can work with you to adjust your dosage if you begin to experience these problems.