Purpose of reviewAlthough mycophenolate mofetil (MMF) has been used successfully to treat a myriad of autoimmune diseases, its complex pharmacokinetics make it difficult to determine the true drug exposure for an individual patient. This review summarizes the body of literature focused on the gold standard measurement of the area under the curve (AUC) of mycophenolic acid (MPA), the active metabolite of MMF. Recent findingsFixed dosing of MMF leads to highly variable drug exposure. Retrospective series have reported improved clinical outcomes when a minimum AUC value from 0 to 12 h (AUC 0-12h ) !30 mg h/l is achieved. MPA levels are affected by various drug interactions, hypoalbuminemia, and renal insufficiency and the measurement of free rather than total MPA levels is prudent in some situations. A limited number of studies employing prospective dose adjustment of MMF based on AUC 0-12h measurements have yielded mixed results. SummaryGiven the wide range of MPA AUC encountered in autoimmune diseases, dose adjustments of MMF based on AUC rather than fixed dosing of MMF should be considered in both clinical practice and clinical trials. Limited sampling strategies have been proposed to improve clinical feasibility of measurements, but a standard is yet to be defined.

Purpose of reviewThis review summarizes the recent literature exploring hydroxychloroquine levels and their relationship with disease activity and risk of toxicity. Recent findingsThere is no clear correlation between weight-based dosing of hydroxychloroquine and the resulting blood levels of the medication. Recent studies have shown that increased hydroxychloroquine levels are associated with lower lupus disease activity and likely also increased risk of medication toxicity.

Background: The aim of this study was to identify risk factors that may predispose breast cancer patients to the development of CNS metastases. Materials & methods: We conducted a matched case–control study of breast cancer patients treated with surgery with curative intent. A total of 71 cases and 71 controls were analyzed, matched by year of surgery. Results: In our multivariable model, positive lymph node status (odds ratio [OR]: 5.08; CI: 2.04–12.65), the use of neoadjuvant chemotherapy (OR: 6.02; CI: 2.06–17.57) and triple-negative breast cancer (OR: 5.44; CI: 1.99–14.90) were statistically significant predictors of the development of CNS metastases. Conclusion: Women with certain risk factors have an increased odds of developing CNS metastases and evaluation of utility in brain metastases screening should be considered.