No abstract

The effect of dietary vitamin K intake on warfarin sensitivity is known only from case reports and few small clinical studies. We followed 50 patients commencing warfarin and consuming their regular diets (for 8 weeks) to study this relationship. A one-week recall dietary questionnaire was completed at weeks 2 and 8. Daily intake of nutrients and vitamin K was calculated from standard tables. Warfarin sensitivity index (WSI) was defined as final INR/final warfarin dose (mg/day/m 2 of body surface area) (week 8).Vitamin K intake was 17-974 (median: 179) g/day. Median WSI was 0.82 (0.31-4.47). A WSI value of 1.1 significantly separated excess (≥250 g/day) from normal (<250 g/day) vitamin K consumers (16/18 vs. 15/32, respectively, p <0.01). The former had lower day 5 INR (median: 1.9 vs. 3.0, p <0.001), needed more warfarin to achieve INR ≥2.0 (32.0 ± 9.2 mg vs. 25.4 ± 6.4 mg, p = 0.009) and required a higher maintenance steady state warfarin dose (5.7 ± 1.7 mg/day vs. 3.5 ± 1.0 mg/day, p <0.001).We conclude that in 32% (16/50) of anticoagulated patients under usual dietary conditions sensitivity to warfarin is decreased by vitamin K intake ≥250 g/day.

IMPORTANCE Retinitis pigmentosa (RP) is the leading cause of incurable inherited blindness in the developed world, with an estimated prevalence of 1 in 3500 individuals. Therefore, it is important to develop new treatments for this disease. OBJECTIVE To determine the effect of oral treatment with 9-cis β-carotene on visual function of patients with RP. DESIGN Randomized, double-masked, placebo-controlled, crossover clinical trial. SETTING University tertiary medical facility. PARTICIPANTS Thirty-four patients with RP who were at least 18 years of age. Twenty-nine patients completed the study and were included in the analysis. INTERVENTIONS Patients were treated daily for 90 days with capsules containing 300 mg of 9-cis β-carotene-rich alga Dunaliella bardawil (β-carotene, approximately 20 mg) or placebo (starch). Following a 90-day washout period, they were treated for 90 days with the other capsules. MAIN OUTCOMES AND MEASURES The primary outcome was the change for both eyes from baseline to the end of each treatment in dark-adapted maximal electroretinographic b-wave amplitude. The secondary outcomes were the changes in light-adapted maximal b-wave amplitude, dark-and light-adapted visual field, and best-corrected visual acuity. RESULTS The mean change in dark-adapted maximal b-wave amplitude relative to initial baseline was +8.4 μV for 9-cis β-carotene vs −5.9 μV for placebo (P = .001). Ten participants (34.5%) had an increase of more than 10 μV for both eyes (range, 11-42 μV) after 9-cis β-carotene treatment compared with no participants after placebo treatment. The percentage change in light-adapted b-wave response was +17.8% for 9-cis β-carotene vs −3.0% for placebo (P = .01). No significant differences were found between the groups for visual field and best-corrected visual acuity. No adverse effects were observed. CONCLUSIONS AND RELEVANCE Treatment with 9-cis β-carotene significantly increased retinal function in patients with RP under the tested conditions. The optimal therapeutic regimen will be determined in future, larger clinical trials. 9-cis β-Carotene may represent a new therapeutic approach for some patients with RP. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01256697

While allergy history might influence glioma, meningioma, and acoustic neuroma risk, the observed associations could be due to information or selection bias or reverse causality.

In order to determine the efficacy of the antifibrinolytic agent tranexamic acid (TA) in reducing bleeding and platelet transfusions during the treatment of acute myeloid leukemia (AML), we conducted a randomized placebo-controlled double-blind study. Patients with AML undergoing induction or postremission consolidation chemotherapy were randomized into TA or placebo groups. Patients were not given platelet transfusions prophylactically but only when bleeding occurred. The severity of any bleeding event was scored. Thirty eight patients were randomized during induction. There were no significant differences between the two groups in the number of bleeding events and their severity or in the number of platelet transfusions given. Eighteen patients were studied during consolidation. In contrast, to the induction period, during consolidation there was a significantly less severe bleeding tendency in the TA group resulting in a lower platelet transfusion requirement [3.7 +/- 4.1 vs. 9.3 +/- 3.3 platelet units (p < .05)]. TA was well tolerated and no side effects were seen and no specific thromboembolic events were noticed. We conclude that giving TA during the thrombocytopenic period of AML patients undergoing consolidation chemotherapy is beneficial and safely reduces platelet transfusions.