A descriptive pharmacokinetic/pharmacodynamic analysis of continuous infusion ceftazidime-avibactam for treating DTR gram-negative infections in a case series of critically ill patients undergoing continuous veno-venous haemodiafiltration (CVVHDF).

PURPOSE: To explore pharmacokinetic/pharmacodynamic (PK/PD) profile of continuous infusion (CI) ceftazidime-avibactam for treating difficult-to-treat resistant Gram-negative (DTR-GN) infections in critical patients undergoing continuous venovenous haemodiafiltration (CVVHDF). MATERIALS AND METHODS: Patients treated with CI ceftazidime-avibactam for DTR-GN infections during CVVHDF were retrospectively assessed. Ceftazidime and avibactam concentrations were measured at steady-state and the free fraction (fCss) was calculated. Total clearance (CLtot) of both agents were calculated and the impact of CVVHDF intensity was assessed by linear regression. The joint PK/PD target of ceftazidime-avibactam was defined as optimal when both fCss/MIC≥4 for ceftazidime and fCss/CT > 1 for avibactam were achieved. Relationship between ceftazidime-avibactam PK/PD targets and microbiological outcome was assessed. RESULTS: Eight patients with DTR-GN infections were retrieved. Median fCss were 84.5 (73.7-87.7 mg/L) for ceftazidime and 24.8 mg/L (20.7-25.8 mg/L) for avibactam. Median CLtot was 2.39 L/h (2.05-2.96 L/h) for ceftazidime and 2.56 L/h (2.12-2.98 L/h) for avibactam. Median CVVHDF dose was 38.6 mL/h/kg (35.9-40.0 mL/kg/h). CLtot were linearly correlated with CVVHDF dose (r = 0.53;p = 0.03, and r = 0.64;p = 0.006, respectively). The joint PK/PD targets were optimal granting microbiological eradication in all the assessable cases. CONCLUSION: CI administration of 1.25-2.5 g q8h ceftazidime-avibactam may allow prompt attainment and maintenance of optimal joint PK/PD targets during high-intensity CVVHDF.

Improved Efficacy of Pregabalin by Restoring Plasma Vitamin D Levels in Migraine: a Case Report.

Migraine appears to be the most common neurological syndrome in primary care. Pain in migraine is mediated by the release of inflammatory mediators at the level of nerves and blood vessels. The antioxidant and neuroprotective effects of vitamin D in the central nervous system suggest that deficiency of this vitamin can be involved in migraine. Moreover, low serum levels of vitamin D correlates with a higher incidence of chronic pain, including migraine and in co-administered with anti-migraine treatment reduces the frequency of migraine attacks. We report a 46-year old woman affected by migraine, anxiety and mild depressive mood (MSQ score: 24; BDI score: 34; VAS score: 8) that partially improved with pregabalin treatment (VAS: 5). Laboratory findings documented low serum levels of vitamin D (25-hydroxy-vitamin D: 12 ng/mL; normal range: 20-100 ng/mL; 1-25 di-hydroxy-vitamin D: 19 ng/mL, normal range: 25-66 ng/mL). The treatment with 10,000 UI vitamin D during pregabalin therapy induced an improvement of clinical symptoms (pain, anxiety and depression) and of the quality of life. This case report suggest that in chronic migraine patient with anxiety and mild mood depression in treatment with pregabalin a supplementation of vitamin D improvement the clinical symptoms of migraine and a modulation of inhibitoy synaptic neurotransmission may explain this effect in our migraine patient.

What is the Current Role for Vitamin D and the Risk of Stroke?

INTRODUCTION: Increasing evidence supports the relationship between vitamin D and stroke. Vitamin D has now been proposed as a prognostic biomarker also for functional outcome in stroke patients. METHODS: A revision of the data suggests that low vitamin D is associated more with ischemic than with haemorrhagic stroke, even if the role of optimal vitamin D levels for vascular wall is still unclear. Vitamin D deficiency induces with different mechanisms an alteration of vascular wall. RESULTS: However, to date, the research supporting the effectiveness of vitamin D supplementation in stroke and in post-stroke recovery is still inadequate and conclusive evidences have not been published. CONCLUSION: In this review, we provide a better understanding of the role of vitamin D in stroke.

Conventional and New Antiepileptic Drugs on Vitamin D and Bone Health: What We Know to Date?

The treatment with antiepileptic drugs (AEDs), in particular conventional drugs, induces an increased risk of fractures in women and in epileptic patients in treatment with AEDs for more than 12 years. A supplementation with calcium and vitamin D is suggested in patients chronically treated with some AEDs and there are recommendations to do so. The lack of significant conclusive evidence about the effects of conventional and newer AEDs on bone metabolism needs for more clinical studies in order to perform an appropriate use of calcium and vitamin D supplementation in young and ederly epileptic patients.

Increase in plasma homocysteine levels induced by drug treatments in neurologic patients.

Homocysteine (Hcy) is a thyol amino acid resulting from de-methylation of methionine, an essential amino acid derived from dietary proteins. It is metabolized through two pathways: re-methylation and transsulfuration, which use as cofactors folate, vitamin B6 and vitamin B12. Hyperhomocysteinemia has been identified as a risk factor for cerebrovascular disease, dementia, impaired cognitive function and depression. Several drugs may interfere with metabolic pathways of Hcy, leading to an alteration of plasma Hcy levels. Lipid-lowering agents, used to reduce the risk of cerebral venous thrombosis or occlusive vascular disease in patients with high levels of plasmatic lipids, can increase plasma Hcy levels. Hyperhomocysteinemia has been also documented in Parkinson disease patients treated with levodopa and in epileptic patients after chronic treatment with antiepileptic drugs. In contrast, vitamins supplementations may be warranted in patients treated with lipid-lowering agents, levodopa and antiepileptic drugs in order to maintain normal plasma Hcy values. In contrast, higher doses of vitamins can induce dysfunctions in central and peripheral nervous system; therefore excessive supplements should be avoided.