Inclusion Criteria:  Patients willing and able to give informed consent for participation in the study Ability to understand study procedures and to comply with it for the duration of the study. Subjects of both sexes, the age range between 18 and 70 years old. Serum uric acid above 7 mg / dl. Estimated glomerular filtration rate by MDRD abbreviated formula less than 60 ml / min / 1.73 m2 and above 15 ml / min / 1.73 m2. Stability of renal function (serum creatinine increase without exceeding 50% in the three months before the start of the study). Clinically stable in terms of no hospitalizations of cardiovascular events in the 3 months before the study began.  Exclusion Criteria:  Drop active in the 60 days prior to study initiation. Use of allopurinol within 60 days preceding baseline Active infections within 30 days prior to baseline. Patients with systemic inflammatory disease Infection with HIV, Hepatitis C and Hepatitis B. History of cancer within 5 years prior to the first dose of study medication Chronic liver disease. Immunosuppressive therapy. Pregnant women, breastfeeding or planning to become pregnant. Allergy or sensitive to allopurinol. Addiction to drugs or alcohol, in the opinion of the investigator, may interfere with compliance with study requirements. Inability or unwillingness of the individual or legal guardian or representative to give written informed consent.