Serum caffeine concentrations in preterm infants: a retrospective study

Therapeutic drug monitoring is generally unnecessary in caffeine treatment for apnea of prematurity, as serum caffeine concentrations in preterm infants are normally markedly lower than those at which caffeine intoxication occurs. However, several studies have reported preterm infants having developed toxicity. This retrospective observational study, conducted at a tertiary center in Kagawa, Japan, aimed to evaluate the correlation between the maintenance dose and serum caffeine concentrations and determine the maintenance dose leading to suggested toxic caffeine levels. We included 24 preterm infants (gestational age, 27 ± 2.9 weeks; body weight, 991 ± 297 g) who were treated with caffeine citrate for apnea of prematurity between 2018 and 2021, and 272 samples were analyzed. Our primary outcome measure was the maintenance dose leading to suggested toxic caffeine levels. We found a positive correlation between caffeine dose and serum caffeine concentrations (p < 0.05, r = 0.72). At doses of ≥ 8 mg/kg/day, 15% (16/109) of patients had serum caffeine concentrations above the suggested toxic levels. Patients who receive doses ≥ 8 mg/kg/day risk reaching the suggested toxic serum caffeine levels. It remains unclear whether suggested toxic caffeine concentrations are detrimental to neurological prognosis. Further investigation is required to understand the clinical effects/outcomes of high serum levels of caffeine and to obtain long-term neurodevelopmental follow-up data.

Caffeine for the Pharmacological Treatment of Apnea of Prematurity in the NICU: Dose Selection Conundrum, Therapeutic Drug Monitoring and Genetic Factors

Caffeine citrate is the drug of choice for the pharmacological treatment of apnea of prematurity. Factors such as maturity and genetic variation contribute to the interindividual variability in the clinical response to caffeine therapy in preterm infants, making the optimal dose administered controversial. Moreover, the necessity for therapeutic drug monitoring (TDM) of caffeine is still worth discussing due to the need to achieve the desired target concentrations as well as concerns about the safety of higher doses. Therefore, we reviewed the pharmacokinetic profile of caffeine in preterm infants, evidence of the safety and efficacy of different doses of caffeine, therapeutic concentration ranges of caffeine and impact of genetic variability on caffeine therapy. Whereas the safety and efficacy of standard-dose caffeine have been demonstrated, evidence for the safety of higher administered doses is insufficient. Thus, preterm infants who lack clinical response to standard-dose caffeine therapy are of interest for TDM when dose optimization is performed. Polymorphisms in pharmacodynamics-related genes, but not in pharmacokinetics-related genes, have a significant impact on the interindividual variability in clinical response to caffeine therapy. For preterm infants lacking clinical response, how to develop individualized medication regimens for caffeine remains to be explored.

Pharmacokinetics, pharmacodynamics and metabolism of caffeine in newborns

The plasma elimination half-life of caffeine in the newborn is approximately 100 h. Caffeine is rapidly absorbed with complete bioavailability following oral dosing. Switching between parenteral and oral administration requires no dose adjustments. Caffeine has wide interindividual pharmacodynamic variability and a wide therapeutic index in preterm newborns. Thresholds of measurable efficacy on respiratory drive have been documented at plasma levels around 2 mg/L. At these low levels, caffeine competitively inhibits adenosine receptors (A1 and A2A). The toxicity threshold is ill-defined and possibly as high as 60 mg/L which can be lethal in adults. High doses of caffeine may produce better control of apnea. However, at high systemic drug concentrations, the pharmacodynamic actions of caffeine become more complex and worrisome. They include inhibition of GABA receptors and cholinergic receptors in addition to adenosine receptor inhibition, intracellular calcium mobilization and actions on adrenergic, dopaminergic and phosphodiesterase systems. The role of pharmacogenomic factors as determinants of neonatal pharmacologic response and clinical effects remains to be explored.

Caffeine for preterm infants: Fixed standard dose, adjustments for age or high dose?

Caffeine is an effective treatment for apnea of prematurity and has several important benefits, including decreasing respiratory morbidity and motor impairment. In this article, we focus on the dose of caffeine. We review the evidence regarding the efficacy and safety of standard caffeine dosing and alternative dosing approaches, including the use of high dose caffeine and routine dose adjustments for age. Current evidence suggests high dose caffeine may provide additional benefit in reducing the risk of bronchopulmonary dysplasia and extubation failure, but may also increase the risk of cerebellar hemorrhage and seizures. Increasing the standard caffeine citrate dose every 1-2 weeks to a goal dose of 8 mg per kilogram every 24 h may help maintain therapeutic effect. We conclude by highlighting the need for additional trials before high dose caffeine is routinely used.

Impact of Caffeine Boluses and Caffeine Discontinuation on Apnea and Hypoxemia in Preterm Infants

Background: Apnea of prematurity often occurs during and following caffeine therapy. We hypothesized that number of apnea events would be impacted by adjustments in caffeine therapy. Materials and Methods: An automated algorithm was used in all infants ≤32 weeks gestation admitted to a level IV Neonatal Intensive Care Unit from 2009 to 2014 to analyze chest impedance, electrocardiogram, and oxygen saturation data around the time of serum caffeine levels, caffeine boluses while on maintenance therapy, and caffeine discontinuation. Episodes of central apnea/bradycardia/desaturation (ABDs), and percent time with SpO₂ <88% and <75% were measured. Results: ABDs were analyzed in 302 preterm infants (mean gestational age 27.6 weeks) around the time of 485 serum caffeine levels, 90 caffeine boluses, and 273 episodes of caffeine discontinuation. Higher serum caffeine levels were not associated with fewer ABDs or higher heart rate. For caffeine boluses given due to clinically recognized spells, hypoxemia and algorithm-detected ABDs decreased day 1-2 after the bolus compared to the day before and day of the bolus (mean 4.4 events/day after vs. 6.6 before, p = 0.004). After caffeine discontinuation, there was no change in hypoxemia and a small increase in ABDs (2 events/day 3-5 days after discontinuation vs. 1 event/day before and >5 days after, p < 0.01). This increase in ABDs occurred irrespective of gestational age, respiratory support, or postmenstrual age at the time caffeine was stopped. Conclusions: In this retrospective analysis, caffeine boluses and caffeine discontinuation were associated with a small change in the number of ABD events in preterm infants.

Pharmacological management of sleep apnoea

Obstructive sleep apnoea poses a significant health hazard that is associated with leading causes of mortality and morbidity. Nasal continuous positive airway pressure is the primary treatment modality, with surgical treatments as alternatives. Oral appliances and pharmacological therapy remain adjunctive modalities. Non-specific treatments include weight loss, postural therapy and behavioural measures. Pharmacotherapy goals include the reduction of risk factors for sleep apnoea; correction of underlying predisposing metabolic diseases, such as hypothyroidism or acromegaly; treatment of associated symptoms, including excessive daytime sleepiness; and prevention of apnoeas/hypopnoeas. This paper reviews data supporting the treatment of sleep apnoea with various pharmacological agents, including intranasal corticosteroids, decongestant sprays, nicotine therapy, opiate antagonists, methylxanthine derivatives, oestrogen and progesterone, testosterone, thyroid hormone, growth hormone therapy for acromegaly, beta-blockers, alpha-adrenergic agonists, angiotensin-converting enzyme inhibitors, glutamate antagonists, acetazolamide, selective serotonin re-uptake inhibitors, tricyclic antidepressants, physostigmine, modafinil and TNF-alpha antagonists, in addition to supplemental oxygen, and carbon dioxide inhalation. Some of these drugs have received very little testing and are the subject of few research articles.

Treatment of apnea of prematurity

In the last decade, knowledge regarding the neurodevelopment and functional aspects of the respiratory centers during postnatal maturation has increased substantially. However, an increase in such knowledge has not provided a basis for change in practice. The diagnosis of apnea of prematurity (AOP) is one of exclusion. All causes of secondary apnea must be ruled out before initiating treatment for AOP. Treatment will depend on the etiology as well as effectiveness and tolerability of the treatment by the patient. The primary goal of any treatment of AOP is to prevent the frequency of apnea lasting >20 seconds, and/or those that are shorter, but associated with cyanosis and bradycardia. The clinical management of AOP is not much different today than it was two decades ago, with pharmacologic and nonpharmacologic treatment options remaining the mainstay of therapy. Methylxanthines are still the most widely used pharmacologic agents. Due to the wider therapeutic index of caffeine and ease of once daily administration, it should be the preferred agent. Doxapram, or nonpharmacologic treatment measures such as nasal continuous positive airway pressure, may be considered in infants who are unresponsive to methylxanthine treatment alone. Treatment should be continued until there is complete resolution of apnea, and for some time thereafter. The choice of method for weaning treatment remains one of individual physician preference. Discharge from hospital after apnea requires close monitoring and some infants will require home apnea monitors. The decision to provide a home apnea monitor should be individualized for each patient, depending on the effectiveness of treatment and clinical response.

Caffeine citrate: a review of its use in apnoea of prematurity

Apnoea of prematurity is a common condition in neonates born at less than 37 weeks' gestational age; it affects approximately 90% of premature neonates weighing under 1000 g at birth, and 25% of infants with a birthweight of less than 2500 g. Caffeine, a methylxanthine which occurs naturally in many plants, has been used for over 20 years to treat apnoea of prematurity. In a recent double-blind, placebo-controlled trial, apnoea was eliminated or reduced by at least 50% in significantly more neonates receiving caffeine citrate as first-line treatment than those receiving placebo. In a nonblind trial, caffeine citrate was more effective at reducing apnoeic episodes when compared with neonates receiving no treatment. Caffeine as first-line treatment demonstrated similar efficacy to theophylline or aminophylline (theophylline ethylenediamine) in 4 small randomised studies. Caffeine citrate was generally well tolerated in short term clinical trials, with very few adverse events reported. Caffeine was associated with fewer adverse events than theophylline in randomised trials. No differences in the incidence of individual adverse events were reported between caffeine citrate and placebo in a double-blind, randomised trial. Long term tolerability data are not yet available.

CONCLUSIONS

Caffeine citrate was generally well tolerated by neonates in clinical trials and it decreased the incidence of apnoea of prematurity compared with placebo. It has demonstrated similar efficacy to theophylline, but is generally better tolerated and has a wider therapeutic index. Caffeine citrate should, therefore, be considered the drug of choice when pharmacological treatment of apnoea of prematurity is required.

Caffeine citrate for the treatment of apnea of prematurity: a double-blind, placebo-controlled study

STUDY OBJECTIVE

To evaluate the efficacy and safety of caffeine citrate for treatment of apnea of prematurity.

DESIGN

Multicenter, parallel, randomized, double-blind, placebo-controlled trial with open-label rescue.

SETTING

Nine neonatal intensive care units.

PATIENTS

Eighty-five infants, 28-32 weeks postconception and 24 hours or more after birth who had six or more apnea episodes within 24 hours.

INTERVENTION

Caffeine citrate 10 mg/kg (as caffeine base) administered intravenously, followed by 2.5 mg/kg/day orally or intravenously, or placebo, for up to 10 days. Infants failing double-blind therapy could receive open-label rescue.

MEASUREMENTS AND MAIN RESULTS

Success was defined as 50% or greater reduction in apnea episodes and elimination of apnea. Caffeine citrate was significantly more effective than placebo in reducing apnea episodes by at least 50% in 6 days (p<0.05), and approached statistical significance (p<0.10) in 3 days. It was significantly better than placebo in eliminating apnea in 5 days (p<0.05), and approached significance (p<0.10) in 2 days. The number of infants with an aggregate of 7-10 days of at least a 50% reduction in apnea events or elimination of apnea was significantly higher in the caffeine citrate than in the placebo group. Adverse events did not differ significantly between groups. No correlations were found between success and mean daily plasma concentrations or baseline characteristics. Volume of distribution and clearance increased with weight, supporting weight-adjusted dosing of caffeine citrate.

CONCLUSION

Caffeine citrate 10 mg/kg caffeine base (equivalent to 20 mg/kg caffeine citrate) intravenously followed by 2.5 mg/kg/day caffeine base (equivalent to 5 mg/kg/day caffeine citrate) either intravenously or orally for 10 days is safe and effective for treating apnea of prematurity in infants 28-32 weeks postconception.

Consequences on the newborn of chronic maternal consumption of coffee during gestation and lactation: a review

The present review is devoted to effects on the newborn of maternal ingestion of caffeine during gestation and lactation. In rodents, caffeine is able to induce malformations, but usually at high doses never encountered in humans; indeed, when caffeine is administered in fractioned quantities during the day, as it is the case with human caffeine intake, caffeine is no longer a teratogen in rodents. Caffeine ingested during gestation induces a dose-dependent decrease in body weight, but only for large doses (> 7 cups/day of coffee), whereas it has no effect at moderate doses. Maternal caffeine consumption during gestation affects hematologic parameters in both rat and human infants and induces long-term effects on sleep, locomotion, learning abilities, emotivity and anxiety in rodent offspring, whereas in humans, more studies are needed to determine the consequences of early caffeine exposure on behavior. Investigators do not agree on the quantities of the methylxanthine found in breast milk, but caffeine does not change breast milk composition, and rather, stimulates milk production. We conclude in this review that maternal caffeine consumption in moderate amounts during gestation and lactation has no measurable consequences on the fetus and newborn infant. Pregnant mothers, however, should be advised to consume coffee and caffeinated beverages in moderation, especially because of the prolonged half-life of caffeine both during the last trimester of pregnancy and in the newborn infant.