Effect of gender and CYP2C9 and CYP2C8 polymorphisms on the pharmacokinetics of ibuprofen enantiomers

Enantioselective separation and determination of ibuprofen: Stereoselective pharmacokinetics, pharmacodynamics and analytical methods

Ibuprofen (IBP), the 29th most prescribed drug in the United States in 2019, is a widely used nonsteroidal anti-inflammatory drug (NSAID) comprising two enantiomers, (R)-IBP and (S)-IBP, collectively known as (RS)-IBP. This critical review examines analytical techniques for the enantioselective separation and determination of IBP enantiomers, crucial for pharmaceutical and clinical applications. The review focuses on state-of-the-art methods, including chromatographic techniques including high-performance liquid chromatography, gas chromatography, liquid chromatography-tandem mass spectrometry, and some other techniques. This review addresses pharmacokinetics, pharmacology, and side effects of each enantiomer, ensuring safe drug usage. By consolidating diverse analytical methods and their applicability in different matrices, this review serves as a valuable resource for researchers, analysts, and practitioners in pharmaceutical analysis, pharmacology, and clinical studies.

Comparison of intravenous ibuprofen pharmacokinetics between Caucasian and Chinese populations using physiologically based pharmacokinetics modeling and simulation

BACKGROUND

Intravenous ibuprofen, a nonsteroidal anti-inflammatory drug, is widely used as an antipyretic and analgesic in adults and children. This study was designed to evaluate ethnic differences by comparing the pharmacokinetics of intravenous ibuprofen in Caucasian and Chinese populations using physiologically based pharmacokinetics (PBPK) modeling and simulation.

METHODS

A PBPK model for intravenous ibuprofen was developed in adults and children utilizing the Simcyp Simulator. The model was tested and verified against published literature and unpublished data obtained from the Caucasian adult population, Caucasian pediatric population and Chinese adult population.

RESULTS

The developed PBPK model could adequately pilot the pharmacokinetics of intravenous ibuprofen, and the major observed values were within the 90% prediction interval in both adults and children. Both folding errors of the maximum peak concentration (Cmax) and area under the concentration-time curve (AUC) were 1.5-fold less in the Caucasian and Chinese populations. In addition, no significant differences in weight-normalized Cmax and AUC were observed between the Caucasian and Chinese adult populations. Moreover, there were no obvious pharmacokinetic differences between the Caucasian and Chinese pediatric populations with intravenous infusion (10 minutes) of 10 mg/kg by age group.

CONCLUSION

This study indicates that the pharmacokinetic profile and the parameters of intravenous ibuprofen are analogous in Caucasian and Chinese populations, either adults or children. In addition, this study provides effective evidence that the dosing scheme of intravenous ibuprofen in Chinese children can remain the same as the regimen that the original company (Caldolor®) provided.

Association of CYP2C9∗3 and CYP2C8∗3 Non-Functional Alleles with Ibuprofen-Induced Upper Gastrointestinal Toxicity in a Saudi Patient

Ibuprofen is a non-steroidal anti-inflammatory drug (NSAID) widely used to alleviate pain and inflammation. Although it is generally considered safe, common adverse drug reactions of ibuprofen include stomach pain, nausea, and heartburn. It can also cause gastrointestinal (GI) bleeding, especially in individuals with a history of GI ulcers or bleeding disorders. Ibuprofen is predominantly metabolized by the cytochrome P450 (CYP) enzymes CYP2C9 and CYP2C8. Individuals carrying the CYP2C9∗3 or CYP2C8∗3 non-functional alleles have reduced enzyme activities resulting in elevated ibuprofen plasma concentrations and half-life. We presented a case of a 31-year-old Saudi female patient with a history of rheumatoid arthritis (RA) who had taken ibuprofen at 600 mg twice daily for eight weeks. The patient presented to the emergency department with symptoms including nausea, vomiting, severe abdominal pain, and black tarry stools. An emergency esophagogastroduodenoscopy was performed on the patient, which revealed a deep bleeding ulcer measuring 1 × 1 cm in the antrum of the stomach. Laboratory investigations indicated anemia (hemoglobin: 7.21 g/dL and hematocrit: 22.40 g/dl). The patient received intravenous proton pump inhibitors and a packed red blood cell transfusion. Genetic analysis revealed that the patient was a carrier of CYP2C9∗3 and CYP2C8∗3 variant alleles, indicating that the patient is a poor metabolizer for both enzymes. The patient's symptoms improved over the subsequent days, and she was discharged with instructions to avoid NSAIDs. This is the first reported Saudi patient homozygous for CYP2C9∗3 and CYP2C8∗3 variant alleles, which led to ibuprofen-induced upper GI toxicity. This case demonstrates the importance of contemplating CYP2C9 and CYP2C8 genetic variations when administrating NSAIDs like ibuprofen. Careful assessment of the risks and benefits of NSAID therapy in each patient and consideration of alternative pain management strategies must be conducted when appropriate.

Enzymatic activity of 38 CYP2C9 genotypes on ibuprofen

BACKGROUND AND OBJECTIVE

Ibuprofen, a common non-steroidal anti-inflammatory drug, is used clinically for pain relief and antipyretic treatment worldwide. However, regular or long-term use of ibuprofen may lead to a series of adverse reactions, including gastrointestinal bleeding, hypertension and kidney injury. Previous studies have shown that CYP2C9 gene polymorphism plays an important role in the elimination of various drugs, which leads to the variation in drug efficacy. This study aimed to evaluate the effect of 38 CYP2C9 genotypes on ibuprofen metabolism.

METHODS

Thirty-eight recombinant human CYP2C9 microsomal enzymes were obtained using a frugiperda 21 insect expression system according to a previously described method. Assessment of the catalytic function of these variants was completed via a mature incubation system: 5 pmol CYP2C9*1 and 38 CYP2C9 variants recombinant human microsomes, 5 μL cytochrome B5, ibuprofen (5-1000 μM), and Tris-HCl buffer (pH 7.4). The ibuprofen metabolite contents were determined using HPLC analysis. HPLC analysis included a UV detector, Plus-C18 column, and mobile phase [50% acetonitrile and 50% water (containing 0.05% trifluoroacetic acid)]. The kinetic parameters of the CYP2C9 genotypes were obtained by Michaelis-Menten curve fitting.

RESULTS

The intrinsic clearance (CL_int) of eight variants was not significantly different from CYP2C9*1; four CYP2C9 variants (CYP2C9*38, *44, *53 and *59) showed significantly higher CL_int (increase by 35%-230%) than that of the wild-type; the remaining twenty-six variants exhibited significantly reduced CL_int (reduced by 30%-99%) compared to that of the wild-type.

CONCLUSION

This is the first systematic evaluation of the catalytic characteristics of 38 CYP2C9 genotypes involved ibuprofen metabolism. Our results provide a corresponding supplement to studies on CYP2C9 gene polymorphisms and kinetic characteristics of different variants. We need to focus on poor metabolizers (PMs) with severely abnormal metabolic functions, because they are more susceptible to drug exposure.

Sex Differences in Patent Ductus Arteriosus Incidence and Response to Pharmacological Treatment in Preterm Infants: A Systematic Review, Meta-Analysis and Meta-Regression

A widely accepted concept in perinatal medicine is that boys are more susceptible than girls to complications of prematurity. However, whether this ‘male disadvantage of prematurity’ also involves persistent patent ductus arteriosus (PDA) has been scarcely investigated. Our aim was to conduct a systematic review and meta-analysis on studies addressing sex differences in the risk of developing PDA among preterm infants. We also investigated whether the response to pharmacological treatment of PDA differs between boys and girls. PubMed/Medline and Embase databases were searched. The random-effects male/female risk ratio (RR) and 95% confidence interval (CI) were calculated. We included 146 studies (357,781 infants). Meta-analysis could not demonstrate sex differences in risk of developing any PDA (37 studies, RR 1.03, 95% CI 0.97 to 1.08), hemodynamically significant PDA (81 studies, RR 1.00, 95% CI 0.97 to 1.02), or in the rate of response to pharmacological treatment (45 studies, RR 1.01, 95% CI 0.98 to 1.04). Subgroup analysis and meta-regression showed that the absence of sex differences was maintained over the years and in different geographic settings. In conclusion, both the incidence of PDA in preterm infants and the response rate to pharmacological treatment of PDA are not different between preterm boys and girls.

Pharmacogenetics and Pain Treatment with a Focus on Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) and Antidepressants: A Systematic Review

Background: This systematic review summarizes the impact of pharmacogenetics on the effect and safety of non-steroidal anti-inflammatory drugs (NSAIDs) and antidepressants when used for pain treatment. Methods: A systematic literature search was performed according to the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines regarding the human in vivo efficacy and safety of NSAIDs and antidepressants in pain treatment that take pharmacogenetic parameters into consideration. Studies were collected from PubMed, Scopus, and Web of Science up to the cutoff date 18 October 2021. Results: Twenty-five articles out of the 6547 initially detected publications were identified. Relevant medication–gene interactions were noted for drug safety. Interactions important for pain management were detected for (1) ibuprofen/CYP2C9; (2) celecoxib/CYP2C9; (3) piroxicam/CYP2C8, CYP2C9; (4) diclofenac/CYP2C9, UGT2B7, CYP2C8, ABCC2; (5) meloxicam/CYP2C9; (6) aspirin/CYP2C9, SLCO1B1, and CHST2; (7) amitriptyline/CYP2D6 and CYP2C19; (8) imipramine/CYP2C19; (9) nortriptyline/CYP2C19, CYP2D6, ABCB1; and (10) escitalopram/HTR2C, CYP2C19, and CYP1A2. Conclusions: Overall, a lack of well powered human in vivo studies assessing the pharmacogenetics in pain patients treated with NSAIDs or antidepressants is noted. Studies indicate a higher risk for partly severe side effects for the CYP2C9 poor metabolizers and NSAIDs. Further in vivo studies are needed to consolidate the relevant polymorphisms in NSAID safety as well as in the efficacy of NSAIDs and antidepressants in pain management.

Physiologically based pharmacokinetic (PBPK) modeling of piroxicam with regard to CYP2C9 genetic polymorphism

Piroxicam is a non-steroidal anti-inflammatory drug used to alleviate symptoms of osteoarthritis and rheumatoid arthritis. CYP2C9 genetic polymorphism significantly influences the pharmacokinetics of piroxicam. The objective of this study was to develop and validate the piroxicam physiologically based pharmacokinetic (PBPK) model related to CYP2C9 genetic polymorphism. PK-Sim^® version 10.0 was used for the PBPK modeling. The PBPK model was evaluated by predicted and observed plasma concentration-time profiles, fold errors of predicted to observed pharmacokinetic parameters, and a goodness-of-fit plot. The turnover number (k_cat) of CYP2C9 was adjusted to capture the pharmacokinetics of piroxicam in different CYP2C9 genotypes. The population PBPK model overall accurately described and predicted the plasma concentration-time profiles in different CYP2C9 genotypes. In our simulations, predicted AUC_inf in CYP2C9*1/*2, CYP2C9*1/*3, and CYP2C9*3/*3 genotypes were 1.83-, 2.07-, and 6.43-fold higher than CYP2C9*1/*1 genotype, respectively. All fold error values for AUC, C_max, and t_1/2 were included in the acceptance criterion with the ranges of 0.57-1.59, 0.63-1.39, and 0.65-1.51, respectively. The range of fold error values for predicted versus observed plasma concentrations was 0.11-3.13. 93.9% of fold error values were within the two-fold range. Average fold error, absolute average fold error, and root mean square error were 0.93, 1.27, and 0.72, respectively. Our model accurately captured the pharmacokinetic alterations of piroxicam according to CYP2C9 genetic polymorphism.

CYP2C9*3 Increases the Ibuprofen Response of Hemodynamically Significant Patent Ductus Arteriosus in the Infants with Gestational Age of More Than 30 Weeks

Hemodynamically significant patent ductus arteriosus (hsPDA) is a severe condition in newborns. Ibuprofen is an effective treatment to reduce the severe complications and the need for surgical treatment. Several single-nucleotide polymorphisms (SNPs) were related to the ibuprofen metabolism, treatment effects, and the onset of side effects. The effects of SNPs on hsPDA response after ibuprofen treatment are unknown. Therefore, in this study, we recruited hsPDA patients with standard ibuprofen treatment. Those patients had participated in China Neonatal Genomes Project (CNGP, ClinicalTrials.gov Identifier: NCT03931707) with next-generation sequencing data. We reanalyzed the sequencing data and compared the allele frequencies of known ibuprofen-related SNPs between ibuprofen Responder and Non-responder groups. In total, 185 hsPDA patients were recruited with gestational age (GA) ranging from 24 to 40 weeks. No significant differences were detected in the basic information, period of ibuprofen treatment, rate of conservative treatment, complications, and side effects between ibuprofen Responder group and Non-responder group. Totally, 17 hsPDA carried CYP2C9*3 and one with CYP2C9*2 were detected. In the GA group of more than 30 GA weeks (GA > 30 wks group), we found higher allele frequency of CYP2C9*3 in Responder group than in Non-responder group (16% vs. 0, p = 0.0391). In the GA group of less than 30 GA weeks (GA ≤ 30 wks group), the sum allele frequency of CYP2C9*3 and CYP2C9*2 had no stastical difference between two groups (Responder group vs. Non-responder group, 13% vs. 11%, p = 0.768). Therefore, we came to conclude that genetic tests of CYP2C9*3 site may benefit the prediction of ibuprofen treatment outcome for hsPDA patients with gestational age of more than 30 weeks.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s43657-021-00028-9.

Establishment and validation of an SIL-IS LC-MS/MS method for the determination of ibuprofen in human plasma and its pharmacokinetic study

In this work, we developed and validated a highly sensitive, rapid and stable LC-MS/MS method for the determination of ibuprofen in human plasma with ibuprofen-d3 as a stable isotopically labeled internal standard (SIL-IS). Human plasma samples were prepared by one-step protein precipitation. The chromatographic separation was achieved on a Poroshell 120 EC-C₁₈ (2.1 × 50 mm, 2.7 μm). Aqueous solution (containing 0.05% acetic acid and 5 mm NH₄ Ac) and methanol were selected as the mobile phase with gradient elution. An electrospray ionization source was applied and operated in negative ion mode. Multiple reaction monitoring mode was used for quantification using target fragment ions m/z 205.0 → 161.1 for ibuprofen and m/z 208.0 → 164.0 for SIL-IS, respectively. This method exhibited a linear range of 0.05-36 μg/ml for ibuprofen with correlation coefficient >0.99. Mean recoveries of ibuprofen in human plasma ranged from 78.4 to 80.9%. The RSD of intra- and inter-day precision were both < 5%. The accuracy was between 88.2 and 103.67%. The matrix effect was negligible in human plasma, including lipidemia and hemolytic plasma. A simple, efficient and accurate LC-MS/MS method was successfully established and applied to a pharmacokinetic study in healthy Chinese volunteers after a single oral administration of ibuprofen granules.

Ibuprofen enantiomers in premature neonates with patent ductus arteriosus: Preliminary data on an unexpected pharmacokinetic profile of S(+)-ibuprofen

S(+)-ibuprofen (S-IBU) and R(-)-ibuprofen (R-IBU) concentrations were measured in 16 neonates with patent ductus arteriosus during a cycle of therapy (three intravenous doses of 10-5-5 mg kg-1 at 24-h intervals), at the end of the first infusion and 6, 24, 48, and 72 h later. Data were analyzed with a PK model that included enantiomer elimination rate constants and the R- to S-IBU conversion rate constant. The T½ of S-IBU in the newborn was much longer than in adults (41.8 vs. ≈2 h), whereas the T½ of R-IBU appeared to be the same (2.3 h). The mean fraction of R- to S-IBU conversion was much the same as in adults (0.41 vs. ≈0.60). S-IBU concentrations measured 6 h after the first dose were higher than at the end of the infusion in 10 out of 16 cases, and in five cases, they remained higher even after 24 h. This behavior is unprecedented and may be attributable to a rapid R-to-S conversion overlapping with a slow S-IBU elimination rate. In 13 of the 16 neonates, S-IBU concentrations at 48 and/or 72 h were lower than expected, probably due to the rapid postnatal maturation of the newborn's liver metabolism.

Influence of Genetic Polymorphisms on the Response to Tramadol, Ibuprofen, and the Combination in Patients With Moderate to Severe Pain After Dental Surgery

PURPOSE

We aimed to elucidate the influence on analgesic effect of genetic polymorphisms in enzymes responsible for biotransformation of tramadol and ibuprofen or other possible genes involved in their mechanism of action.

METHODS

The study population comprised 118 patients from a multicenter, randomized, double-blind, placebo-controlled, Phase III clinical trial that assessed the analgesic efficacy and tolerability of a single dose of ibuprofen (arginine)/tramadol 400/37.5 mg compared with ibuprofen arginine 400 mg alone, tramadol 50 mg alone, and placebo in patients with moderate to severe pain after dental surgery. We analyzed 32 polymorphisms in the cytochrome P450 (CYP) enzymes COMT, ABCB1, SLC22A1, OPRM1, and SLC22A1.

FINDINGS

We did not find any statistically significant difference among CYP2C9 phenotypes related to ibuprofen response, although CYP2C9 poor metabolizers had a longer effect (higher pain relief at 6 hours). Likewise, we did not find any statistically significant difference among PTGS2 genotypes, contradicting previously publications.

IMPLICATIONS

There was not a clear effect of CYP2D6 phenotype on tramadol response, although CYP2D6 poor metabolizers had a slower analgesic effect. Concerning the transport of CYP2D6, we observed a better response in individuals carrying ABCB1 mutated alleles, which might correlate with higher tramadol plasma levels. Finally, we found a statistically significant better response in patients carrying the OPRM1 A118G G allele, which contradicts the previous reports. Measuring the active metabolite O-desmethyl-tramadol formation would be of great importance to better evaluate this association because O-desmethyl-tramadol has a higher μ-opioid receptor affinity compared with the parent drug. EudraCT.ema.europa.eu identifier: 2013-004637-33.

Assessment of the impact of PTGS1, PTGS2 and CYP2C9 polymorphisms on pain, effectiveness and safety of NSAID therapies

Cyclooxygenase 1 and 2 (COX-1, COX-2) are enzymes that catalyze the first reaction in the arachidonic acid pathway. COXs are the therapeutic target for non-steroidal anti-inflammatory drugs. Inhibition of COX enzymatic activity has an analgesic, anti-inflammatory and sometimes antiplatelet effect. Single-nucleotide polymorphisms (SNPs) within genes encoding COX-1 and COX-2 (PTGS1, PTGS2) influence the risk of pain and their intensity in some diseases. They also affect the effectiveness of NSAID therapy in rheumatoid diseases. Moreover, the relationship between certain polymorphisms of PTGS2 and a higher risk of migraine and the development of aspirin resistance in the prophylaxis of cardiovascular diseases was demonstrated. The isoform of cytochrome P450, CYP2C9 has a significant influence on the efficacy and safety of NSAID use. It is responsible for the metabolism and speed of removal of these drugs. The occurrence of some of its polymorphic forms is associated with a decrease in CYP2C9 enzymatic activity, leading to changes in the pharmacokinetics and pharmacodynamics of NSAIDs. The prolonged half-life and decrease in clearance of these drugs lead to serious side effects such as hepatotoxicity, nephrotoxicity, anaphylactic reactions, cardiovascular or gastrointestinal incidents. Studies on polymorphisms of cyclooxygenases and CYP2C9 may improve the safety and efficacy of NSAIDs therapy by adjusting the dose to individual polymorphic variants, as well as expanding knowledge about the pathomechanism of inflammatory diseases.

Clinical Pharmacogenetics Implementation Consortium Guideline (CPIC) for CYP2C9 and Nonsteroidal Anti-Inflammatory Drugs

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most commonly used analgesics due to their lack of addictive potential. However, NSAIDs have the potential to cause serious gastrointestinal, renal, and cardiovascular adverse events. CYP2C9 polymorphisms influence metabolism and clearance of several drugs in this class, thereby affecting drug exposure and potentially safety. We summarize evidence from the published literature supporting these associations and provide therapeutic recommendations for NSAIDs based on CYP2C9 genotype (updates at www.cpicpgx.org).

Enantiomer specific pharmacokinetics of ibuprofen in preterm neonates with patent ductus arteriosus

Aims

Racemic ibuprofen is widely used for the treatment of preterm neonates with patent ductus arteriosus. Currently used bodyweight‐based dosing guidelines are based on total ibuprofen, while only the S‐enantiomer of ibuprofen is pharmacologically active. We aimed to optimize ibuprofen dosing for preterm neonates of different ages based on an enantiomer‐specific population pharmacokinetic model.

Methods

We prospectively collected 210 plasma samples of 67 preterm neonates treated with ibuprofen for patent ductus arteriosus (median gestational age [GA] 26 [range 24–30] weeks, median body weight 0.83 [0.45–1.59] kg, median postnatal age [PNA] 3 [1–12] days), and developed a population pharmacokinetic model for S‐ and R‐ibuprofen.

Results

We found that S‐ibuprofen clearance (CL_S, 3.98 mL/h [relative standard error {RSE} 8%]) increases with PNA and GA, with exponents of 2.25 (RSE 6%) and 5.81 (RSE 15%), respectively. Additionally, a 3.11‐fold higher CL_S was estimated for preterm neonates born small for GA (RSE 34%). Clearance of R‐ibuprofen was found to be high compared to CL_S (18 mL/h [RSE 24%]), resulting in a low contribution of R‐ibuprofen to total ibuprofen exposure. Current body weight was identified as covariate on both volume of distribution of S‐ibuprofen and R‐ibuprofen.

Conclusion

S‐ibuprofen clearance shows important maturation, especially with PNA, resulting in an up to 3‐fold increase in CL_S during a 3‐day treatment regimen. This rapid increase in clearance needs to be incorporated in dosing guidelines by adjusting the dose for every day after birth to achieve equal ibuprofen exposure.

Individuals with CYP2C8 and CYP2C9 reduced metabolism haplotypes self-adjusted ibuprofen dose in the Coriell Personalized Medicine Collaborative

OBJECTIVES

The objectives of this study were to determine whether differences in CYP2C8 and CYP2C9 haplotype influence the dose of ibuprofen self-administered by individuals, and to examine the potential relationship between CYP2C8 and CYP2C9 reduced metabolism haplotypes and adverse events.

PARTICIPANTS AND METHODS

We investigated relationships between genetic variations in CYP2C8 and CYP2C9 and ibuprofen use, dose, and side effects (reported by questionnaire) in 445 participants from the Coriell Personalized Medicine Collaborative.

RESULTS

Carriers of reduced metabolism haplotypes for CYP2C8 (*2, *3, *4) and CYP2C9 (*2, *3) were significantly (P=0.0171) more likely than those lacking these variants to take less than the recommended dose of ibuprofen, after controlling for sex, age, race, and cohort. In contrast to ibuprofen dose, there were no differences in ibuprofen use frequency or reported side effects based on haplotype. However, there are often no early signs of acute kidney injury, the most serious side effect of elevated ibuprofen exposure.

CONCLUSION

These results suggest a subset of individuals with genetic variation in CYP2C8 and CYP2C9 recognize that they obtain adequate drug efficacy with lower ibuprofen doses, or take lower doses due to prior side effects. However, most (82.6%) individuals with reduced metabolism haplotypes nonetheless took recommended or higher doses, potentially putting them at increased risk for side effects.

AKR1D1*36 C>T (rs1872930) allelic variant is associated with variability of the CYP2C9 genotype predicted pharmacokinetics of ibuprofen enantiomers - a pilot study in healthy volunteers

The relative contribution of CYP2C9 allelic variants to the pharmacokinetics (PK) of ibuprofen (IBP) enantiomers has been studied extensively, but the potential clinical benefit of pharmacogenetically guided IBP treatment is not evident yet. The role of AKR1D1*36C>T (rs 1872930) allelic variant in interindividual variability of CYP450 mediated drug metabolism was recently elucidated. A total of 27 healthy male subjects, volunteers in IBP single-dose two-way cross-over bioequivalence studies were genotyped for CYP2C9*2, CYP2C9*3 and AKR1D1*36 polymorphisms. The correlation between CYP2C9 and AKR1D1 genetic profile and the PK parameters for S-(+) and R-(-)-IBP was evaluated. Remarkable changes in the PK values pointing to reduced CYP2C9 enzyme activity were detected only in the CYP2C9*2 allelic variant carriers. Statistically significant association between the AKR1D1*36 allele and the increased IBP metabolism (low AUC0-t and 0-∞, high Cltot and short tmax values for both enantiomers) was observed in subjects carrying the CYP2C9 *1/*3 or CYP2C9*1/*1 genotype. The clinical value of concomitant CYP2C9 and AKR1D1 genotyping has to be further verified.

The dark side of ibuprofen in the treatment of patent ductus arteriosus: could paracetamol be the solution?

INTRODUCTION

Patent ductus arteriosus (PDA) persistence is associated, in prematures, to several complications. The optimal PDA management is still under debate, especially regarding the best therapeutic approach and the time to treat. The available drugs are not exempt from contraindications and side effects; ibuprofen itself, although representing the first-choice therapy, can show nephrotoxicity and other complications. Paracetamol seems a valid alternative to classic nonsteroidal anti-inflammatory Drugs, with a lower toxicity. Areas covered: Through an analysis of the published literature on ibuprofen and paracetamol effects in preterm neonates, this review compares the available treatments for PDA, analyzing the mechanisms underlining ibuprofen-associated nephrotoxicity and the eventual paracetamol-induced hepatic damage, also providing an update of what has been yet demonstrated and a clear description of the still open issues. Expert Opinion: Paracetamol is an acceptable alternative in case of contraindication to ibuprofen; its toxicity, in this setting, is very low. Lower doses may be effective, with even fewer risks. In the future, paracetamol could represent an efficacious first-line therapy, although its safety, optimal dosage, and global impact have to be fully clarified through long-term trials, also in the perspective of an individualized and person-based therapy taking into account the extraordinary individual variability.

Paracetamol in Patent Ductus Arteriosus Treatment: Efficacious and Safe?

In preterm infants, failure or delay in spontaneous closure of Ductus Arteriosus (DA), resulting in the condition of Patent Ductus Arteriosus (PDA), represents a significant issue. A prolonged situation of PDA can be associated with several short- and long-term complications. Despite years of researches and clinical experience on PDA management, unresolved questions about the treatment and heterogeneity of clinical practices in different centers still remain, in particular regarding timing and modality of intervention. Nowadays, the most reasonable strategy seems to be reserving the treatment only to hemodynamically significant PDA. The first-line therapy is medical, and ibuprofen, related to several side effects especially in terms of nephrotoxicity, is the drug of choice. Administration of oral or intravenous paracetamol (acetaminophen) recently gained attention, appearing effective as traditional nonsteroidal anti-inflammatory drugs (NSAIDs) in PDA closure, with lower toxicity. The results of the studies analyzed in this review mostly support paracetamol efficacy in ductal closure, with inconstant low and transient elevation of liver enzymes as reported side effect. However, more studies are needed to confirm if this therapy shows a real safety profile and to evaluate its long-term outcomes, before considering paracetamol as first-choice drug in PDA treatment.