No Evidence of a Drug-Drug Interaction Between Letermovir (MK-8228) and Mycophenolate Mofetil

Introduction: Letermovir (MK-8228) is a potent, oncedaily inhibitor of the cytomegalovirus (CMV) terminase complex that is being developed for the prophylaxis of CMV infection in transplant patients. This study evaluated the pharmacokinetic interactions, safety, and tolerability of letermovir when coadministered in healthy subjects with mycophenolate mofetil (MMF), which is the morpholinoethyl ester prodrug of mycophenolic acid (MPA). Methods: This was an open-label trial in 14 healthy female subjects that explored the pharmacokinetic parameters of a single 1 g oral dose of MMF administered alone on Day 1 and coadministered on Day 12 with 480 mg oral once-daily letermovir given on Day 5 and from Day 8 continued through Day 16. Letermovir PK was assessed at single dose (Day 5) and at steady state on Day 12 (with MMF) and Day 16 (alone following MMF washout). Results: Coadministration of 480 mg qd letermovir at steady state with a single dose of 1 g of MMF had no effect on the pharmacokinetics of MPA. The MPA AUC0-inf and Cmax geometric mean ratios (GMRs) [90% confidence interval] for the comparison (MMF with letermovir/ MMF alone) were 1.08 [0.96, 1.21] and 0.96 [0.81, 1.13], respectively. Coadministration of a single dose of 1 g MMF with 480 mg qd letermovir at steady state had no clinically meaningful effect on the pharmacokinetics of letermovir, with AUC0-24 and Cmax GMR of 1.18 [1.04, 1.32] and 1.11 [0.93, 1.34], respectively. The letermovir geometric mean accumulation ratio (Day 16/Day 5) and 95% CI were 1.13 [0.90, 1.42] for AUC0-24 and 1.01 [ 0.79, 1.28] f or Cmax, indicating that accumulation of letermovir when administered as daily doses is minimal. All related AEs were reported as mild in severity and resolved. Conclusions: Multiple-dose administration of 480 mg letermovir daily with a single dose of 1 g MMF was generally well tolerated by the healthy subjects in this study. Coadministration of letermovir and MMF had no clinically meaningful effect on the PK of letermovir or MPA. Letermovir and MMF may be coadministered without dose adjustment

Analysis of benzo[a]pyrene metabolites formed by rat hepatic microsomes using high pressure liquid chromatography: optimization of the method

A simple and sensitive method was developed to separate the carcinogenic polycyclic aromatic hydrocarbon (PAH), benzo[a]pyrene (BaP), and six of its oxidation metabolites generated by rat hepatic microsomes enriched with cytochrome P450 (CYP) 1A1, by high pressure liquid chromatography (HPLC). The HPLC method, using an acetonitrile/water gradient as mobile phase and UV detection, provided appropriate separation and detection of both mono- and di-hydroxylated metabolites of BaP as well as BaP diones formed by rat hepatic microsomes and the parental BaP. In this enzymatic system, 3-hydroxy BaP, 9-hydroxy BaP, BaP-4,5-dihydrodiol, BaP-7,8-dihydrodiol, BaP-9,10-dihydrodiol and BaP-dione were generated. Among them the mono-hydroxylated BaP metabolite, 3-hydroxy BaP followed by di-hydroxylated BaP products, BaP-7,8-dihydrodiol and BaP-9,10-dihydrodiol, predominated, while BaP-dione was a minor metabolite. This HPLC method will be useful for further defining the roles of the CYP1A1 enzyme with both in vitro and in vivo models in understanding its real role in activation and detoxification of BaP

Exercise therapy and cognitive behavioural therapy to improve fatigue, daily activity performance and quality of life in Postpoliomyelitis Syndrome: the protocol of the FACTS-2-PPS trial

Contains fulltext : 88661.pdf (publisher's version ) (Open Access)BACKGROUND: Postpoliomyelitis Syndrome (PPS) is a complex of late onset neuromuscular symptoms with new or increased muscle weakness and muscle fatigability as key symptoms. Main clinical complaints are severe fatigue, deterioration in functional abilities and health related quality of life. Rehabilitation management is the mainstay of treatment. Two different therapeutic interventions may be prescribed (1) exercise therapy or (2) cognitive behavioural therapy (CBT). However, the evidence on the effectiveness of both interventions is limited. The primary aim of the FACTS-2-PPS trial is to study the efficacy of exercise therapy and CBT for reducing fatigue and improving activities and quality of life in patients with PPS. Additionally, the working mechanisms, patients' and therapists' expectations of and experiences with both interventions and cost-effectiveness will be evaluated. METHODS/DESIGN: A multi-centre, single-blinded, randomized controlled trial will be conducted. A sample of 81 severely fatigued patients with PPS will be recruited from 3 different university hospitals and their affiliate rehabilitation centres. Patients will be randomized to one of three groups i.e. (1) exercise therapy + usual care, (2) CBT + usual care, (3) usual care. At baseline, immediately post-intervention and at 3- and 6-months follow-up, fatigue, activities, quality of life and secondary outcomes will be assessed. Costs will be based on a cost questionnaire, and statistical analyses on GEE (generalized estimated equations). Analysis will also consider mechanisms of change during therapy. A responsive evaluation will be conducted to monitor the implementation process and to investigate the perspectives of patients and therapists on both interventions. DISCUSSION: A major strength of the FACTS-2-PPS study is the use of a mixed methods design in which a responsive and economic evaluation runs parallel to the trial. The results of this study will generate new evidence for the rehabilitation treatment of persons with PPS. TRIAL REGISTRATION: Dutch Trial Register NTR1371

Concentrations of cadmium, zinc and copper in sediments and brown shrimp (Crangon crangon L.) from the Severn Estuary and Bristol Channel, UK

Cd, Zn and Cu levels were determined in sediments and Crangon crangon from 9 sites in the Severn Estuary/Bristol Channel during winter 1999. Metal levels in both shrimp and sediments varied significantly between sites and were related to proximity of input and/or sediment type. In the upper Estuary, Cd levels in shrimp were 100x higher than other reported values whereas sediment Cd contamination was comparable. It is suggested that high Cd levels in shrimp are due to the high inputs and enhanced bioavailability of metal during winter

Induction of nevi and skin tumors in Ink4a/Arf Xpa knockout mice by neonatal, intermittent, or chronic UVB exposures.

Nevi and melanomas correlate to childhood and intermittent solar UV exposure, xeroderma pigmentosum patients run increased risk, and p16(Ink4a) expression is often lost in malignant progression. To ascertain the effect of these risk factors, pigmented hairless Ink4a/Arf-, Xpa- knockout mice were subjected to various combinations of neonatal [7,12-dimethylbenz(a)anthracene (DMBA) or UVB exposure] and adult treatments (12-O-tetradecanoylphorbol-13-acetate or subacute daily UVB exposure or intermittent overexposure). Nevi occurred earliest, grew largest, and were most numerous in mice exposed to DMBA followed by intermittent UVB overexposure [effect of six minimal edemal doses (MED), 1 x /2 weeks > 4 MED 1 x /wk]. Neonatal UV exposure enhanced nevus induction but lost its effect after 200 days. The Xpa(-/-) mice proved exquisitely sensitive to UV-driven nevus induction, indicating the involvement of pyrimidine dimer DNA lesions, but Xpa(+/+) mice developed many more nevi (>40 per mouse) at high UV dosages not tolerated by Xpa(-/-) mice. Ink4a/Arf(-/-) mice developed most skin tumors faster, but surprisingly developed nevi slower than their heterozygous counterparts especially after neonatal UV exposure. Despite raising >1,600 nevi, only six melanomas arose in our experiments with Ink4a/Arf knockout mice (five of which in Xpa(+/+) mice at high UV dosages). In contrast to human nevi, these nevi lacked hotspot mutations in Braf or Ras genes, possibly explaining the lack of malignant progression in the Ink4a/Arf(-/-) mice. Hence, although our experiments did not effectively emulate human melanoma, they provided clear evidence that intermittent UV overexposure strongly stimulates and the Ink4a/Arf(-/-) genotype may actually impair nevus development