Enteral L Citrulline Supplementation in Preterm Infants - Safety, Efficacy and Dosing

September 27, 2021 updated by: The University of Texas Medical Branch, Galveston
Oral L-citrulline supplementation may prevent and/or decrease the severity of chronic lung disease associated with pulmonary hypertension in preterm infants. Since oral L-citrulline supplementation has never been studied in preterm infants before, the side effect profile and appropriate dosing are still unknown. In this pilot study, the investigators will determine the safety profile, efficacy and appropriate dosing of oral L-citrulline in preterm infants. In the future, information from this study will be utilized to conduct a randomized placebo-controlled trial to evaluate the role of L-citrulline supplementation in treating BPD_PH.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Bronchopulmonary dysplasia (BPD) is the most common chronic lung disease in preterm infants (PI). Preterm birth causes disruption in pulmonary vascular growth that leads to decreased vascular surface area that increases pulmonary vascular resistance (PVR). Increased PVR leads to altered vasoreactivity and structural remodeling with intimal hyperplasia and increased muscularization of the small pulmonary arteries. There is no definite treatment for BPD_PH.

Nitric Oxide: Nitric Oxide (NO) is a potent pulmonary vasodilator. Endothelial Nitric oxide synthase (eNOS) mediates production of NO from L-Arginine. L-citrulline is a precursor for L-arginine. L-Arginine is a precursor of nitric oxide (NO). In infants with BPD_PH, there are decreased levels of L-arginine & L-citrulline with decreased production of NO (measured by urinary nitrates & nitrites) leading to increased PVR. Several studies have shown the benefit of oral L-citrulline supplementation in increasing serum citrulline levels, increasing NO production and reducing pulmonary hypertension. Oral L-arginine was not effective in increasing NO production in previous studies and it was due to increased break down of oral L-arginine by intestinal arginases.

Source of L-arginine in preterm infants: Routinely, extremely premature infants receive nutrition as total parental nutrition (TPN i.e. infants get infusion of protein, fat and carbohydrate via central venous line) that contains L-arginine (approximately 1mg/1mL) to metabolize ammonia via urea cycle. PIs receive adequate amount of intra venous arginine from TPN. Routinely, PIs are started with small volumes of enteral feeds which are increased slowly overtime. TPN is slowly decreased as enteral feeds are increasing. As the TPN is going down, intra venous L-arginine intake also drops down and ultimately when the PI are off TPN, they don't get any IV supplemental L-arginine.

Why oral citrulline: Enteral feeds (formula as well as breast milk) is poor source of arginine. Once PIs are on full enteral feed, an enteral feed is the only source of arginine. Interestingly, 40% of enteral arginine gets metabolized by arginase enzyme present in intestine. We speculate that plasma levels of arginine drop once TPN is discontinued and infants are on full feeds. Oral L-arginine has poor bio-availability that is why oral L-arginine supplementation does not increase blood levels of arginine. Since oral citrulline has high bioavailability, the best way to increase serum arginine levels is by oral citrulline supplementation. Oral supplementation of L-citrulline in preterm infants once they are off TPN will likely to increase arginine levels and NO production.

Safety of oral citrulline: L-citrulline has been safely used for decades in patients with urea cycle defects. It has been used in pediatric patients with sickle cell disease and in infants undergoing cardiac surgery. No side effects were reported in these studies. In a study in newborn rats exposed to hyperoxia, L-citrulline caused a marked increase in arginase-2 expression in the lungs and this could have an impact on lung development and remodeling. However, this is only a theoretical risk.

Study Type

Interventional

Enrollment (Actual)

42

Phase

  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Texas
      • Galveston, Texas, United States, 77550
        • University of Texas Medical Branch

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

No older than 6 months (Child)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Infants less than or equal to 30 weeks' gestational age born at UTMB, Galveston.
  • Parents have provided informed consent/assent in a manner that is approved by the IRB

Exclusion Criteria:

  • Known congenital or chromosomal anomalies.
  • Congenital heart disease affecting cardio-respiratory system (other than PDA, PFO or ASD)
  • Necrotizing enterocolitis, sepsis, or any condition requiring surgery prior to recruitment

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: L-citrulline 100 mg/kg/day
50 mg/kg given two times a day (100 mg/kg/day) for total 7 days.
Dietary supplement: Enteral L-citrulline

L-Citrulline as 10 % solution (100 mg/ml) will be provided to the bedside nurse by the Investigational Pediatric Pharmacy. The drug will be given via gavage feeding by bolus infusions followed by a 0.5 ml water flush twice daily (0900 and 2100). Bolus dosing will be needed due to the small volumes (0.5-1.5 ml per dose in most infants). The volume of nasogastric tubing used in preterm infants (Ameritus 4.0 Fr 50 cm) is 0.48 ml, therefore we will follow the administration with 0.5 ml of saline/water flush to ensure all the study drug is delivered to the patient.

Administration of study drug - Will be given via gavage feeding tube twice daily (0900 +/- 30 mins, 2100 +/- 30 mins). L-citrulline will be given by the bedside nurse as a bolus followed by 0.5 ml water flush. L-citrulline will be given separate from feeds to avoid any confusion.

Study drug will be started when infant has been off of TPN for at least 3 days so that IV arginine in TPN does not interfere.
Experimental: L-citrulline 200 mg/kg/day
100 mg/kg given two times a day (200 mg/kg/day) for total 7 days
Dietary supplement: Enteral L-citrulline

L-Citrulline as 10 % solution (100 mg/ml) will be provided to the bedside nurse by the Investigational Pediatric Pharmacy. The drug will be given via gavage feeding by bolus infusions followed by a 0.5 ml water flush twice daily (0900 and 2100). Bolus dosing will be needed due to the small volumes (0.5-1.5 ml per dose in most infants). The volume of nasogastric tubing used in preterm infants (Ameritus 4.0 Fr 50 cm) is 0.48 ml, therefore we will follow the administration with 0.5 ml of saline/water flush to ensure all the study drug is delivered to the patient.

Administration of study drug - Will be given via gavage feeding tube twice daily (0900 +/- 30 mins, 2100 +/- 30 mins). L-citrulline will be given by the bedside nurse as a bolus followed by 0.5 ml water flush. L-citrulline will be given separate from feeds to avoid any confusion.

Study drug will be started when infant has been off of TPN for at least 3 days so that IV arginine in TPN does not interfere.
Experimental: L-citrulline 300 mg/kg/day
150 mg/kg given two times a day (300 mg/kg/day) for total 7 days.
Dietary supplement: Enteral L-citrulline

L-Citrulline as 10 % solution (100 mg/ml) will be provided to the bedside nurse by the Investigational Pediatric Pharmacy. The drug will be given via gavage feeding by bolus infusions followed by a 0.5 ml water flush twice daily (0900 and 2100). Bolus dosing will be needed due to the small volumes (0.5-1.5 ml per dose in most infants). The volume of nasogastric tubing used in preterm infants (Ameritus 4.0 Fr 50 cm) is 0.48 ml, therefore we will follow the administration with 0.5 ml of saline/water flush to ensure all the study drug is delivered to the patient.

Administration of study drug - Will be given via gavage feeding tube twice daily (0900 +/- 30 mins, 2100 +/- 30 mins). L-citrulline will be given by the bedside nurse as a bolus followed by 0.5 ml water flush. L-citrulline will be given separate from feeds to avoid any confusion.

Study drug will be started when infant has been off of TPN for at least 3 days so that IV arginine in TPN does not interfere.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Plasma Levels of L-arginine and L-citrulline as Measured by LCMS Approach
Time Frame: During the week of intervention (day 0 - day 7)
L-arginine and citrulline levels in the plasma will be measured via liquid chromatography-mass spectroscopy (LCMS) and a change (increase) in plasma levels of 20% on day 7 from baseline on day 0 will be considered significant.
During the week of intervention (day 0 - day 7)
Safety of L-citrulline in Preterm Infants: Measured by at Least One Adverse Event
Time Frame: During the week of intervention (day 0 - day 7)
Measured by at least one adverse event that are determined to be related to the study drug.
During the week of intervention (day 0 - day 7)
Number of Participants With an Increase Plasma Level of L-citrulline > 37 Micromol/L
Time Frame: During the week of intervention (day 0 - day 7)
Previous studies have shown that a plasma level of > 37 micromol/L was effective in preventing pulmonary hypertension. This study sought to identify the dosing group of L-citrulline required to increase the plasma level of L-citrulline > 37 micromol/L.
During the week of intervention (day 0 - day 7)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

The University of Texas Medical Branch, Galveston

Investigators

  • Principal Investigator: Amna Investigator, MD, University of Texas

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 25, 2018

Primary Completion (Actual)

June 21, 2021

Study Completion (Actual)

June 21, 2021

Study Registration Dates

First Submitted

August 24, 2018

First Submitted That Met QC Criteria

August 27, 2018

First Posted (Actual)

August 28, 2018

Study Record Updates

Last Update Posted (Actual)

October 25, 2021

Last Update Submitted That Met QC Criteria

September 27, 2021

Last Verified

September 1, 2021

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 17-0194

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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