RESUMO
Objective To study the blood concentration of hydroxychloroquine in patients with systemic lupus erythematosus (SLE) treated with different doses, and analyze the relationship between blood concentration of hydroxychloroquine and disease activity, and evaluate its safety.Methods Forty SLE patients were randomly divided into 2 groups, each group contained 20 cases.The patients in group A were treated with hydroxychloroquine (0.4 g, qd), while patients in group B were treated with hydroxychloroquine (0.2 g, qd).The treatment lasted more than six months in every patient.The blood concentrations of hydroxychloro-quine were detected by high performance liquid chromatography.The clinical and laboratory indices were collected.The systemic lupus erythematosus disease activity index (SLEDAI) score was recorded.The doses and varieties of combined hormone, immunosuppressant were recorded.The correlation of blood concentration of hydroxychloroquine and disease activity was analyzed.The significance was determined by Student's t test and Pearson correlation analysis.Results In SLE patients, the average blood concentration of hydro-xychloroquine was (402±190) ng/ml in group A and (150±60) ng/ml in group B (t=7.471, P＜0.01).The disease activities of patients in the two groups showed no significant difference (t=-0.172, P＞0.05).The platelet counts of patients in group A were significantly higher than those in group B[(188±88)×109/L vs (158 ±87) ×109/L] (t=4.375, P＜0.05).However, the other laboratory parameters showed no significant difference between the two groups (P＞0.05).Conclusion The results of this study indicate that the blood concentrations of hydroxy-chloroquine are significantly different in different dosages.The high dose of hydroxy-chloroquine is related to high platelet number in lupus patients.These findings suggest that hydroxychloroquine is safe and effective for SLE patients.