Population pharmacokinetic-pharmacodynamic modeling of acetaminophen in preterm neonates with hemodynamically significant patent ductus arteriosus

Clinical and echocardiography predictors of response to first-line acetaminophen treatment in preterm infants with hemodynamically significant patent ductus arteriosus

OBJECTIVE

To assess clinical and echocardiography predictors of acetaminophen response for the treatment of patent ductus arteriosus (PDA) in preterm neonates.

STUDY DESIGN

Retrospective cohort study of preterm infants born <30 weeks, with a diagnosis of hemodynamically significant PDA, who received 1st line treatment with intravenous acetaminophen during the first 2 postnatal weeks. Response was defined by PDA closure or improvement in PDA score of >50%.

RESULTS

A total of 100 infants were included whose median weight and gestational age at birth were 663 grams and 24.6 weeks respectively. In total, 66 infants were classified as responders and were more likely to have intrauterine growth restriction, exposure to maternal hypertension and chorioamnionitis. Non-response was more common among infants with thrombocytopenia and anemia.

CONCLUSION

Responders were more likely to be IUGR with echocardiography indices of lower preload. Response to 1st line intravenous acetaminophen therapy is comparable to non-steroidal drugs in preterm infants. Relationship of response to acetaminophen to perinatal characteristics requires further characterization.

Pharmacokinetic and Pharmacodynamic Analysis of Acetaminophen and Ibuprofen Dual Therapy for Patent Ductus Arteriosus Closure in Preterm Neonates at Less Than 29 Weeks of Gestation

Patent ductus arteriosus (PDA) is a blood vessel that critically supports fetal circulation. The ductus naturally closes within a few days after birth. However, it can stay open in premature neonates for an extended period of time, which is associated with increased mortality and various co-morbidities. Ibuprofen and indomethacin are currently the only 2 drugs approved for inducing PDA closure, but both have been associated with adverse renal and bleeding events. Clinical evidence suggests that combining acetaminophen (APAP) and ibuprofen treatments can decrease the need for surgical ligation. The objective of this study was to establish a disease-drug-trial model to characterize and predict PDA closure following single and combination drug therapy with ibuprofen and/or APAP in children at less than 29 weeks of gestation. The model was informed by a comprehensive literature review. The results of our analysis suggest that ibuprofen and APAP achieve therapeutic synergy. They further suggest that the younger the preterm neonates, the higher the treatment benefit. A 5-day oral dosing regimen consisting of ibuprofen (20 mg/kg Q24h on day 1, followed by 10 mg/kg Q24h on days 2-5) plus APAP (15 mg/kg Q6h) was deemed appropriate to achieve at least 90% PDA in all preterm neonates evaluated within 1 month of life. The model can now be used to design prospective pediatric trials to evaluate optimal drug combinations for PDA closure in preterm neonates and to refine optimal dosing regimens in cohorts of differing gestational age.

Low dose paracetamol for management of patent ductus arteriosus in very preterm infants: a randomised non-inferiority trial

OBJECTIVE

To compare the efficacy of low dose-short course intravenous paracetamol with a conventional dose regimen for early targeted closure of patent ductus arteriosus (PDA).

DESIGN

Single-centre, double-blinded, active controlled, randomised non-inferiority trial.

SETTING

Level III neonatal intensive care unit in Western India.

PATIENTS

Preterm infants <30 weeks of gestation requiring mechanical ventilation, or continuous positive airway pressure with FiO₂ ≥0.35 and diagnosed with a haemodynamically significant PDA (hsPDA) at 18-24 hours of postnatal age.

INTERVENTIONS

Low dose (10 mg/kg/dose 6 hourly for 72 hours) versus conventional dose (15 mg/kg/dose 6 hourly for 120 hours) intravenous paracetamol treatment.

MAIN OUTCOME MEASURES

Comparison of the rates of ductal closure at completion of sixth postnatal day, using a prespecified non-inferiority margin of 20%.

RESULTS

A total of 102 infants were enrolled. The median gestational age and birth weight of the included infants were 26.4 weeks and 830 g. At completion of the sixth postnatal day, closure of PDA was achieved in 92% of infants in the low dose group as compared with 94% of those in the standard dose group (risk difference: -1.6%, 95% CI: -11.6% to 8.5%, p=0.38). The rates of rescue therapies, adverse effects and other neonatal morbidities were comparable in both groups.

CONCLUSION

In very preterm infants on significant respiratory support, low dose-short course intravenous paracetamol treatment was non-inferior to a conventional dosing regime of paracetamol for closure of hsPDA in the first week of postnatal age. Larger studies with narrow margins of non-inferiority are required to confirm our findings.

TRIAL REGISTRATION NUMBER

CTRI/2017/10/010012.

In vitro to in vivo acetaminophen hepatotoxicity extrapolation using classical schemes, pharmacodynamic models and a multiscale spatial-temporal liver twin

In vitro to in vivo extrapolation represents a critical challenge in toxicology. In this paper we explore extrapolation strategies for acetaminophen (APAP) based on mechanistic models, comparing classical (CL) homogeneous compartment pharmacodynamic (PD) models and a spatial-temporal (ST), multiscale digital twin model resolving liver microarchitecture at cellular resolution. The models integrate consensus detoxification reactions in each individual hepatocyte. We study the consequences of the two model types on the extrapolation and show in which cases these models perform better than the classical extrapolation strategy that is based either on the maximal drug concentration (Cmax) or the area under the pharmacokinetic curve (AUC) of the drug blood concentration. We find that an CL-model based on a well-mixed blood compartment is sufficient to correctly predict the in vivo toxicity from in vitro data. However, the ST-model that integrates more experimental information requires a change of at least one parameter to obtain the same prediction, indicating that spatial compartmentalization may indeed be an important factor.

The Effect of Ibuprofen Exposure and Patient Characteristics on the Closure of the Patent Ductus Arteriosus in Preterm Infants

Spontaneous closure of the ductus arteriosus depends on gestational age (GA) and might be delayed in preterm infants, resulting in patent ductus arteriosus (PDA). Ibuprofen can be administered to enhance closure, but the exposure‐response relationship between ibuprofen and the closure of PDA remains uncertain. We investigated the influence of patient characteristics and ibuprofen exposure on ductus closure. A cohort of preterm infants with PDA and treated with ibuprofen was analyzed. Ibuprofen exposure was based on a previously developed population pharmacokinetic study that was in part based on the same study population. Logistic regression analyses were performed with ductus closure (yes/no) as outcome, to analyze the contribution of ibuprofen exposure and patient characteristics. In our cohort of 263 preterm infants (median GA 26.1 (range: 23.7–30.0) weeks, birthweight 840 (365–1,470) g) receiving ibuprofen treatment consisting of 3 doses that was initiated at a median postnatal age (PNA_start) of 5 (1–32) days, PDA was closed in 55 (21%) patients. Exposure to ibuprofen strongly decreased with PNA_start. Overall, the probability of ductus closure decreased with PNA_start (odds ratio (OR): 0.7, 95% CI: 0.6–0.8) and Z‐score for birthweight (Z_{Birthweight‐for‐GA}; OR: 0.8, 95% CI: 0.6‐1.0), and increased with GA (OR: 1.5, 95% CI: 1.1–1.9). For patients with PNA_start < 1 week, concentrations of ibuprofen, GA, and Z_{Birthweight‐for‐GA} predicted probability of ductus closure. During a window of opportunity for ductus closure within the first days of life, probability of closure depends on GA, Z_{Birthweight‐for‐GA}, and ibuprofen exposure. Increased, yet unstudied dosages might increase the effectivity of ibuprofen beyond the first week of life.

Different approaches for patent ductus arteriosus in premature infants using acetaminophen

BACKGROUND

Acetaminophen use for pharmacological treatment of hemodynamically significant patent ductus arteriosus (hsPDA) in preterm infants is becoming more popular with emerging evidence that it is effective as well as safe alternative for other agents used to close hsPDA.

DATA SOURCES

We performed a narrative review of literature about pharmacological treatment of PDA using acetaminophen.

RESULTS

Acetaminophen was used as a prophylaxis, symptomatic, targeted, and a rescue approach.

CONCLUSIONS

It appears that acetaminophen could be used in different approaches to close the hsPDA. Long-term outcomes of acetaminophen exposure early in life still lack certainty.