Background: Hyperuricemia has been associated with increased risk of endothelial dysfunction, cardiovascular, and renal disease. Allopurinol is a potent xanthine oxidase inhibitor used in hyperuricemic patients. It has been shown to decrease cardiovascular disease and hypertension. However, studies have reported conflicting evidence on its effects on blood pressure (BP) and estimated glomerular filtration rate (GFR) in chronic kidney disease (CKD) patients.
Objective: To demonstrate the effect of allopurinol on BP and estimated GFR in CKD patients.
Material and method: Patients with CKD stage II-III were screened for possible study enrollment. All patients received allopurinol 50 mg once daily for 12 weeks. The main outcomes were to observe the changes of BP and GFR after given treatment.
Results: Forty-four patients were eligible with mean age of 70.14 ± 8.50 years and mean estimated GFR of 43.22 ± 14.44 mL/ min/1.73 m². Serum uric acid decreased significantly from 8.11 ± 2.68 to 7.05 ± 2.38 mg/dL (p = 0.012) at the end of the study. Allopurinol had also statistically significant lower systolic BP (137.72 ± 14.72 to 131.34 ± 12.10 mmHg, p = 0.019) and diastolic BP (79.63 ± 11.56 to 75.43 ± 9.80 mmHg, p = 0.037) at 12 weeks when compared to baseline. There was significant increased in GFR after treatment (43.22 ± 14.44 vs. 45.34 ± 16.09, mL/min/1.73 m², p = 0.029). No serious adverse effects were noted in any of the treated subjects. Two patients (4.5%) in the treatment group had minor skin reaction.
Conclusion: The study results confirmed that 12 weeks of allopurinol treatment affects the values of serum uric acid, BP and GFR in early stage of CKD patients who already received standard antihypertensive agents without any significant serious adverse effects.