Moxifloxacin is routinely used as a probe to confirm assay sensitivity in thorough electrocardiogram (ECG) studies. It has been shown that a meal shortens the QT interval, which may affect pharmacokinetics (PK) and/or pharmacodynamics (PD) of the study drug. However, there is no published data clarifying this issue. There is also a paucity of data investigating ethnic differences of the effects of medicines on QTc. The aims of the study were to compare the effect of different food contents to placebo on the changes in ECG and to demonstrate the effect of insulin, C-peptide and glucose on the ECG. This was done by giving different treatments on separate days, which included intravenous insulin, a high carbohydrate breakfast \[\>70%\], and a calorie reduced low carbohydrate American FDA standard breakfast. Moxifloxacin 400 mg was used as a positive control and was given with and without food to Caucasian and Japanese volunteers to investigate racial differences.
This study was initially performed in 24 healthy Caucasian and Japanese volunteers with an option to increase the sample size to up to 54 volunteers. The decision to increase the sample size to 32 was based on the standard deviation of the ECG intervals observed in the first 24 volunteers. This analysis was performed by an independent statistician under blinded conditions. Each volunteer participated in 2 periods. Each period consisted of 1 baseline day (D-1) followed by 3 study days (D1 - D3) when the various food effect and drug treatments or placebo were administered. All volunteers received all treatments. Moxifloxacin was always given on D3 to prevent any carryover effect and there was a minimum washout period of 3 days in between the 2 periods. How well the treatments (insulin/glucose, high carbohydrate breakfast, calorie reduced breakfast and moxifloxacin) were tolerated by the volunteers was assessed and any side effects noted. We compared the effects of the various treatments between Caucasian and Japanese volunteers. Moxifloxacin and placebo were given to volunteers by mouth, i.e. they were asked to swallow them with water. The different types of breakfast were provided which volunteers were asked to eat. Insulin and glucose were administered intravenously (Insulin/glucose clamp). Hence, the study was performed as an open-label design. This study was conducted as a single site study at Richmond Pharmacology/ St George's University of London.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
32
Subjects receiving drug (400 mg moxifloxacin),having fasted overnight for 10 hours. This is the standard probe for the assessment of assay sensitivity in Thorough QT (TQT) studies.
Calorie reduced FDA standard breakfast (58% fat, low carbohydrates)- On the assumption that increases in C-peptide levels are responsible for the QTc shortening observed after a meal, a lesser effect on QTc compared to a carbohydrate rich breakfast should be observed.
High carbohydrate breakfast (\>70% carbohydrates)- On the assumption that increases in C-peptide levels are responsible for the QTc shortening observed after a meal, a greater effect on QTc compared to a low carbohydrate breakfast (FDA standard breakfast) should be observed.
Currently, there is no published data showing the effects of a single 400 mg oral dose of moxifloxacin on the ECG/QT/QTc after food.
A euglycaemic/hyperinsulinaemic clamp, (DeFronzo, 1979) involves acutely raising the plasma insulin levels to a steady state and maintaining a state of euglycaemia with a glucose infusion, thereby effectively stopping endogenous insulin and C-peptide release. This technique will confirm whether hyperinsulinaemia has any effect on the QT/QTc interval.
Comparison of different meals effect on Moxifloxacin PK profile
Richmond Pharmacology Ltd
London, Tooting, United Kingdom
The Effect of Food (Fasted and Fed State) on the Degree of QT Prolongation Caused by Moxifloxacin
The primary baseline corrections were calculated using averaged QTc baseline values (the mean of all median readings recorded for each time-point on the baseline Day -1). This single value (QTcbaselineAV) was used to calculate ΔQTc for each study period.
Time frame: 0 (pre-dose), 0.25, 0.5, 0.75, 1, 1.5, 2, 2.5, 3, 3.5, 4 and 6 hours post-dose
The Food Effects (Calorie Reduced FDA Breakfast and Carbohydrate Rich Continental Style) on QTcF
Scott et al (2002) demonstrated an increase in the heart rate of 10bpm in some healthy subjects following ingestion of a carbohydrate meal. There was significant correlation between the resultant hyperinsulinaemia and an increase in skeletal muscle blood flow, and sympathetic activity, with a reduction in vascular resistance. If postprandial insulinaemia is a significant influence on the QT interval, then carbohydrate rich meals would be expected to show greater effect. Therefore, to explore this on two separate days of the study subjects will be given one of two different types of breakfast: 1. A high carbohydrate content breakfast, (\>70% carbohydrate) 2. A reduced calorie FDA standard breakfast, (58% fat, low carbohydrate content) to determine effect on QT interval.
Time frame: 0 (pre-dose), 0.25, 0.5, 0.75, 1, 1.5, 2, 2.5, 3, 3.5, 4 and 6 hours post-dose
Moxifloxacin 400 mg (Single Dose) Compared to Placebo on the Mean QT/QTc Interval.
"Moxifloxacin 400mg Fasted" group is reporting the maximum change in QT/QTc interval from placebo treatment.
Time frame: 0 (pre-dose), 0.25, 0.5, 0.75, 1, 1.5, 2, 2.5, 3, 3.5, 4 and 6 hours post-dose
Insulin, Glucose and C-Peptide Effects on the QT/QTc Interval
The effect on QTc was investigated using linear mixed effect models with placebo corrected QTcF (change from average baseline) as a dependent variable and insulin, glucose and C-peptide (placebo corrected) as covariates for the data obtained under the euglycaemic clamp as well as for all data obtained under the clamp and the two types of breakfast.
Time frame: 0 (pre-dose), 0.25, 0.5, 0.75, 1, 1.5, 2, 2.5, 3, 3.5, 4 and 6 hours post-dose
The QTcF Profile of Oral Moxifloxacin (400 mg) in Healthy Japanese Versus Caucasian Subjects
Time frame: 0 (pre-dose), 0.25, 0.5, 0.75, 1, 1.5, 2, 2.5, 3, 3.5, 4 and 6 hours post-dose
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