Introduction: The role of vitamin D in metabolism, bone-mineral regulation, and anti-oxidation effect has drawn researchers’ attention toward its exact role in hemodialysis. Objectives: In this study, the effect of uric acid level reduction on serum 25-hydroxy vitamin D levels in hemodialysis patients was assessed. Patients and Methods: This study is a triple-blind clinical trial conducted on 81 hemodialysis patients suffering from asymptomatic hyperuricemia. Serum uric acid levels were assessed at the start of the study. Then patients were divided randomly into two groups of intervention and control. The intervention group received 100 mg of allopurinol tablets daily for two months. The control group received placebo tablets for the same duration. At the end of the study, 25-hydroxyvitamin D and uric acid levels were assessed. Data were analyzed using SPSS software and chi-square, independent t test, Mann–Whitney U, and Spearman’s rank correlation tests. Results: In our study, two groups of control and intervention were similar in terms of patients’ demographic and hemodialysis characteristics. After the intervention, compared to the control group, the serum uric acid levels were significantly lower in the intervention group, while the level of 25-hydroxyvitamin D showed no significant difference between the two groups. Conclusion: In this study, no significant effect of uric acid lowering therapy with vitamin D elevation in hemodialysis patients was detected. Trial Registration: The trial protocol was approved by the Iranian Registry of Clinical Trials (identifier: IRCT2015041721803N1; https:// en.irct.ir/trial/18996, ethical code#IR.SKUMS.1395.231).

Objective:To review the safety issues surrounding tyrosine kinase inhibitors (TKIs), specifically, hematological adverse effects, cardiovascular issues, renal adverse effects and nephrotoxicity, endocrine system adverse effects, concerns related to the reproductive system, dermatological and gastrointestinal adverse effects. Data Sources: A literature search was performed through Web of Science, PubMed, Google Scholar, Scopus, and the Food and Drug Administration. Data Summary: Several safety issues have been raised following the use of TKIs. Most TKIs show hematological side effects. Considering cardiovascular toxicities, as opposed to imatinib which is relatively safe, new-generation TKIs may be associated with severe cardiovascular side effects. Both acute and chronic renal failure were reported with TKIs such as gefitinib, imatinib, pazopanib, sorafenib, and sunitinib. Many endocrine adverse effects have been reported including hypercholesterolemia and hypertriglyceridemia (with lorlatinib) and thyroid dysfunction (with dasatinib). TKIs may interfere with fetus implantation, growth, and gonadal development. Females receiving TKIs and encountering unwanted pregnancy may have a normal pregnancy, miscarriage, or an abnormality in the fetus. Skin toxicity has been identified as the most debilitating adverse effect in patients receiving EGFR-TKI. Gastrointestinal side effects are common with TKIs. Diarrhea was the most frequently reported adverse effect of many TKIs. Conclusions: TKIs are increasingly taking up a critical role in the treatment of cancers due to their specific action toward malignant cells compared to conventional cytotoxic chemotherapy. Despite a dramatic improvement in the survival of patients with cancer following approval of TKIs, various early and late adverse effects were reported.