Clinical Trial Details
— Status: Active, not recruiting
Administrative data
NCT number |
NCT06351995 |
Other study ID # |
KOR-19-22 |
Secondary ID |
|
Status |
Active, not recruiting |
Phase |
Phase 3
|
First received |
|
Last updated |
|
Start date |
November 6, 2020 |
Est. completion date |
January 1, 2025 |
Study information
Verified date |
April 2024 |
Source |
James J. Peters Veterans Affairs Medical Center |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
To determine a lower effective dose of neostigmine to induce bowel evacuation by
transcutaneous administration by iontophoresis.
Description:
Subjects will progress to receive the standard dose previously reported and employed for
these agents [NEO (0.07 mg/kg) + GLY (0.014 mg/kg)] by transdermal administration by use of a
wired ION system. NEO and GLY can be delivered into the systemic circulation by
transcutaneous route by ION to induce a safe and predictable bowel evacuation in persons with
SCI. If digital rectal stimulation was utilized in the screening session, this method will be
utilized for the remaining sessions as needed at the discretion of the primary investigator.
In the anesthesiology literature, a ratio of NEO to GLY of about 5 to 1 has been employed in
clinical situations. Participants will be requested not to have bowel care for at least 1 day
prior to the study. The subject will assume normal bowel evacuation position until a bowel
movement occurs. Privacy draping and privacy will be provided at the time of bowel
evacuation. The subjects will be monitored for 120 minutes. A minimum of two research
personnel will be present during the study visit to record all of data and perform the tasks
required.
From recent work, it is extrapolated that 85 to 90% of participants will have a bowel
evacuation to transdermal administration of NEO by ION. The pharmacokinetics of only those
who have a bowel evacuation to NEO will be used in the calculation to determine the peak
plasma concentration (PPC) and area under the curve (AUC) of NEO and GLY. The PPC and AUC for
the non-responders to NEO will be analyzed separately; it is speculated that the PPC of NEO
for the non-responders will be blunted-that is, at least below the mean value of the PPC for
NEO administration.
The absorption of study agents is, to a certain extent, subject-specific because of
differential absorption through the skin. As such, each participant is expected to display
differing responses: shorter or longer times to bowel evacuation (or the absence of bowel
evacuation), as well as the absence or presence of cholinergic (increased bowel activity,
bradycardia, bronchoconstriction) or anti-cholinergic activity, as previously described in
the text above. The pharmacokinetic data will, to a large extent, reflect this variability in
transdermal drug absorption. The data collected will include the presence or absence of bowel
evacuation, time to bowel evacuation, consistency (Bristol stool scale), and quantity (by
weight). The presence/number of cholinergic and anti-cholinergic side-effects on a
standardized point scale will be determined, as well as their severity (e.g., mild, moderate,
or severe). Heart rate, blood pressure, oxygen saturation, and pulmonary mechanics (airway
patency by impulse oscillation system) will be recorded at baseline and sequentially at
intervals the initiation of ION (at 5, 10, 15, 20, 30, 45, 60, 90, and 120 minutes).
To quantitate the amount of these agents absorbed into the systemic circulation,
pharmacokinetic studies will be performed for 2 hours after the start of transdermal drug
delivery. Venous blood (2 ml) will be collected into an EDTA tube for both agents at the
following time points: baseline (time zero), 5, 10, 15, 20, 30, 45, 60, 90, 120, 180, 240,
360, and 480 minutes. Upon drawing, the blood will be placed in an ice bath and spun using a
centrifuge within 5 minutes of collection. Upon completion of 5 minutes of centrifugation,
the plasma will be aliquoted into two separate vials, with equal volumes and labeled with
date and time of draw, study information, NEO or GLY testing destination, and the subject's
unique identifier. The transfer vials will be inserted into dry ice for at least 10 minutes,
after which they will be placed into the -80 degrees Celsius freezer. Plasma levels of NEO
and of GLY will be batched and measured at a later date. A file designating the tubes with
random numbers associated with the draw times will be created for each subject to conceal the
sequence of draw and to attempt the removal of possible bias during the measurement and
recording of the concentrations of NEO and GLY. NEO and GLY will be measured by mass
spectroscopy.
To determine the reproducibility of the transdermal absorption of NEO and GLY, as well as the
potential side-effects, subjects will again receive NEO (0.07 mg/kg) + GLY (0.014 mg/kg) by
transdermal administration by use of a wired ION system. Additionally, digital rectal
stimulation will be utilized as needed at the discretion of the primary investigator.
Pharmacokinetic data and all other measurements and questionnaires that were previously
obtained will be acquired once again and compared to Trial 1.
The investigators will have obtained pharmacokinetic data on each participant from Study 1.
From the data acquired, the peak plasma concentration (PPC) and the area under the curve
(AUC) for NEO will be calculated. The hypothesis is that the PPC for NEO will correlate more
closely with bowel evacuation than its AUC, and the AUC for GLY will correlate more closely
with anti-cholinergic symptoms than its PPC, but this prediction is just speculation prior to
obtaining and analyzing the data. If the plasma concentration of each NEO and GLY are solely
responsible for determining biological effects (e.g., cholinergic and anti-cholinergic), then
the investigators would predict that there will be a direct and strong correlation of drug
levels with those endpoints. However, if the biological effects are primary determined by
end-organ responsiveness, then the correlation between drug concentration and observed
endpoints will be tenuous, at best. If both plasma concentration and end-organ responsiveness
play a role in bowel evacuation and cholinergic side-effect, then an effect of plasma
concentrations will still be evident, but not as strong.
Determination of a Lower Effective Dose of NEO to Induce Bowel Evacuation Because 85-90% of
participants are anticipated to have a bowel evacuation from NEO administration at the dose
previously employed (standard dose: NEO 0.07 mg/kg), the dose administered is most probably
well above the lowest effective dose to achieve the biological desired effect ("ceiling
effect"). If the lowest effective dose can be determined, side-effects from NEO
administration will be reduced. As such, to identify the upper limit of the lowest effective
dose, the dose of NEO will be titrated down until the effect on the primary end organ is
lost-that is, until bowel evacuation no longer occurs after drug administration in at least
50% of the participants. Thus, to determine if a lower dose of NEO will still result in bowel
evacuation, participants will have the dose of NEO reduced by 25% (with the dose of GLY also
reduced by 25%). The total volume of the drugs applied to the patch will be kept constant. In
these dose reduction experiments, pharmacokinetic data (e.g., AUC and PPC) will be obtained
on each participant for each reduction in dose of NEO. All other measurements and
questionnaires that were obtained in Study 1 will be performed.