Pharmacokinetics Of Raltegravir Research Articles

Conversion of raltegravir carrying a 1,3,4-oxadiazole ring to a hydrolysis product upon pH changes decreases its antiviral activity.

Raltegravir (RAL), a human immunodeficiency virus (HIV)-1 integrase inhibitor, has been administered as part of antiretroviral therapy. Studies in patients with HIV-1 have shown high variability in the pharmacokinetics of RAL, and in healthy volunteers, coadministration of proton-pump inhibitors has been shown to increase the plasma RAL concentrations. Here, we found that RAL containing a 1,3,4-oxadiazole ring is converted to a hydrolysis product (H-RAL) with a cleaved 1,3,4-oxadiazole ring at pH 1.0 and 13.0 conditions in vitro, thereby reducing the anti-HIV activity of the drug. The inclusion of cyclodextrins (beta-cyclodextrin [βCD], random methyl-βCD [RAM-βCD], and hydroxypropyl-βCD [HP-βCD]) can protect RAL from pH-induced changes. The conversion of RAL to H-RAL was detected by using various mass spectrometry analyses. The chromatogram of H-RAL increased in a time-dependent manner similar to another 1,3,4-oxadiazole-containing drug, zibotentan, using high-performance liquid chromatography. Oral bioavailability and target protein interactions of H-RAL were predicted to be lower than those of RAL. Moreover, H-RAL exhibited significantly reduced anti-HIV-1 activity, whereas combinations with βCD, RAM-βCD, and HP-βCD attenuated this effect in cell-based assays. These findings suggest that βCDs can potentially protect against the conversion of RAL to H-RAL under acidic conditions in the stomach, thereby preserving the anti-HIV-1 effect of RAL. Although clinical trials are needed for evaluation, we anticipate that protective devices such as βCDs may improve the pharmacokinetics of RAL, leading to better treatment outcomes, including reduced dosing, long-term anti-HIV-1 activity, and deeper HIV-1 suppression.

Management of Drug Interactions with Inducers: Onset and Disappearance of Induction on Cytochrome P450 3A4 and Uridine Diphosphate Glucuronosyltransferase 1A1 Substrates.

People living with HIV may present co-morbidities requiring the initiation and subsequently the discontinuation of medications with inducing properties. The time to reach maximal enzyme induction and to return to baseline enzyme levels has not been thoroughly characterized. The aim of this study was to evaluate the onset and disappearance of dolutegravir [uridine diphosphate glucuronosyltransferase (UGT) 1A1 and cytochrome P450 (CYP) 3A4 substrate] and raltegravir (UGT1A1 substrate) induction with strong and moderate inducers using physiologicallybased pharmacokinetic (PBPK) modeling. The predictive performance of the PBPK model to simulate dolutegravir and raltegravir pharmacokinetics and to reproduce the strength of induction was verified using clinical drug-drug interaction studies (steady-state induction) and switch studies (residual induction). The model was considered verified when the predictions were within 2-fold of the observed data. One hundred virtual individuals (50% female) were generated to simulate the unstudied scenarios. The results were used to calculate the fold-change in CYP3A4 and UGT1A1 enzyme levels upon initiation and discontinuation of strong (rifampicin) or moderate (efavirenz or rifabutin) inducers. The time for reaching maximal induction and subsequent disappearance of CYP3A4 induction was 14 days for rifampicin and efavirenz but 7 days for rifabutin. The distinct timelines for the moderate inducers relate to their different half-lives and plasma concentrations. The induction and de-induction processes were more rapid for UGT1A1. Our simulations support the common practice of maintaining the adjusted dosage of a drug for another 2 weeks after stopping an inducer. Furthermore, our simulations suggest that an inducer should be administered for at least 14 days before conducting interaction studies to reach maximal induction.

Relationship between raltegravir trough plasma concentration and virologic response and the impact of therapeutic drug monitoring during pregnancy.

Limited data is available on raltegravir (RAL) pharmacokinetics during pregnancy and the value of therapeutic drug monitoring (TDM) in pregnancy is unknown. This study aims to describe RAL trough plasma concentrations (Ctrough) during pregnancy and review the impact of RAL TDM on outcomes. Women from the prospective mother-infant HIV cohort of Mother and Children's Infectious Diseases Center who received RAL during their pregnancy between 2011-2020 were included. TDM reports were reviewed and Ctrough values estimated when possible, using historical RAL half-lives. We included 76 pregnant women of which 47 underwent TDM. We observed a significant association between virological response and Ctrough (p-value .034) with an increase of 0.1mg/L corresponding to a 2.96 reduction in the risk of having a detectable viral load. The results indicated that in pregnant women a RAL Ctrough threshold of 0.04mg/L has a higher specificity (75%) as compared to our current Ctrough target value of 0.02mg/L (25%) and an acceptable sensitivity (77%). No significant differences were observed between Ctrough at each trimester. When comparing pregnancies with and without TDM, no statistically significant differences were observed in the virologic response during pregnancy and at delivery, or with the need for triple antiretroviral prophylaxis in newborns. An association between RAL Ctrough and viral load was observed and achieving a RAL Ctrough of 0.04mg/L or greater is a predictor of virologic response in pregnant women. The impact of TDM in pregnancy, however, could not be demonstrated.

Influence of UGT1A1 and SLC22A6 polymorphisms on the population pharmacokinetics and pharmacodynamics of raltegravir in HIV-infected adults: a NEAT001/ANRS143 sub-study

Using concentration-time data from the NEAT001/ARNS143 study (single sample at week 4 and 24), we determined raltegravir pharmacokinetic parameters using nonlinear mixed effects modelling (NONMEM v.7.3; 602 samples from 349 patients) and investigated the influence of demographics and SNPs (SLC22A6 and UGT1A1) on raltegravir pharmacokinetics and pharmacodynamics. Demographics and SNPs did not influence raltegravir pharmacokinetics and no significant pharmacokinetic/pharmacodynamic relationships were observed. At week 96, UGT1A1*28/*28 was associated with lower virological failure (p = 0.012), even after adjusting for baseline CD4 count (p = 0.048), but not when adjusted for baseline HIV-1 viral load (p = 0.082) or both (p = 0.089). This is the first study to our knowledge to assess the influence of SNPs on raltegravir pharmacodynamics. The lack of a pharmacokinetic/pharmacodynamic relationship is potentially an artefact of raltegravir’s characteristic high inter and intra-patient variability and also suggesting single time point sampling schedules are inadequate to thoroughly assess the influence of SNPs on raltegravir pharmacokinetics.

Pharmacokinetic/pharmacodynamic investigation of raltegravir with or without lamivudine in the context of HIV-1 pre-exposure prophylaxis (PrEP).

BackgroundTo characterize their potential use in pre-exposure prophylaxis (PrEP) we compared the pharmacokinetics of raltegravir and lamivudine in genital tissue against ex vivo tissue infection with HIV-1.MethodsOpen-label trial of 36 HIV-negative females and males randomized to 7 days raltegravir 400 mg twice daily and 7 days raltegravir 400 mg+lamivudine 150 mg twice daily (after washout), or vice versa. Blood, saliva, rectal fluid, rectal tissue, vaginal fluid and vaginal tissue were sampled at baseline and on and off PrEP during a total of 12 days, for pharmacokinetics and antiviral activity via ex vivo HIV-1BaL challenge. Ex vivo infectivity was compared with baseline. The trial has been registered in https://clinicaltrials.gov/ with the identifier NCT03205566.ResultsSteady state for both drugs was reached by day 4. Dosing with raltegravir alone provided modest ex vivo HIV protection with higher drug levels in rectal tissue and vaginal tissue than in plasma on and off PrEP. Off PrEP, plasma and vaginal concentrations declined rapidly, while persisting in the rectum. On PrEP, the highest lamivudine concentrations were in the rectum, followed by vaginal tissue then plasma. Lamivudine washout was rapid in plasma, while persisting in the rectum and vagina. Raltegravir/lamivudine increased ex vivo protection on and off PrEP compared with raltegravir alone, reaching maximum protection at day 2 in rectal tissue and at day 8 in vaginal tissue.ConclusionsRaltegravir 400 mg+lamivudine 150 mg showed high levels of ex vivo HIV protection, associated with high drug concentrations persisting after discontinuation in vaginal and rectal compartments, supporting further investigation of these agents for PrEP.

Effect of Pregnancy on Unbound Raltegravir Concentrations in the ANRS 160 RalFe Trial.

A population pharmacokinetic model was developed to explore the pharmacokinetics modification of unbound raltegravir during pregnancy. The RalFe ANRS160 study was a nonrandomized, open-label, multicenter trial enrolling HIV-infected pregnant women receiving a combined antiretroviral regimen containing 400 mg raltegravir twice daily. Biological samples were collected during the third trimester of pregnancy (between 30 and 37 weeks of gestational age) and at postpartum (4 to 6 weeks after delivery). A population pharmacokinetic model was developed with Monolix software. A total of 360 plasma samples were collected from 43 women during pregnancy and postpartum. The unbound raltegravir was described by a one-compartment model with a transit compartment with first-order absorption, evolving to bound raltegravir (by a linear binding to albumin) or metabolism to RAL-glucuronide or to a first-order elimination, with a circadian rhythm. During pregnancy, the absorption was decreased and delayed and the raltegravir elimination clearance and glucuronidation increased by 37%. Median total and unbound area under the curve from 0 to 12 h significantly decreased by 36% and 27% during pregnancy. Median total trough concentration (Ctrough) decreased significantly in the evening (28%); however, the median total Ctrough in the morning, unbound Ctrough in the morning, and unbound Ctrough in the evening showed a nonsignificant decrease of 16%, 1%, and 15%, respectively, during pregnancy compared to the postpartum period. This is the first study reporting the pharmacokinetics of unbound raltegravir during pregnancy. As unbound Ctrough did not significantly decrease during the third trimester, the pregnancy effect on raltegravir unbound concentrations was not considered clinically relevant. (This study has been registered at ClinicalTrials.gov under identifier NCT02099474.).

Concurrent administration with multivalent metal cation preparations or polycationic polymer preparations inhibits the absorption of raltegravir via its chelation.

Raltegravir (RAL) that can form chelates with multivalent metal cations shows lateral interactions with multivalent metal cation and polycationic polymer. We investigated the interactions of RAL with multivalent metal cation preparations, Al(OH)3 and LaCO3 , and polycationic polymer preparations, bixalomer (Bxl) and sevelamer (Svl). Immediately before the oral administration of 40mg/kg RAL, the rats were administered orally with the vehicle, Al(OH)3 , LaCO3 , Bxl, or Svl, and the time course of RAL serum concentration was followed. The in vitro binding affinity of RAL with multivalent metal cation and polycationic polymer was also evaluated using isothermal titration calorimetry (ITC). When Al(OH)3 , LaCO3 , Bxl, or Svl was concomitantly administered with RAL, the maximum concentration and area under the curve were significantly lower than those when RAL was administered alone. ITC showed the interaction of RAL with Al(OH)3 as an enthalpy-driven reaction and its interactions with LaCO3 and Bxl as entropy-enthalpy mixed reactions. The interaction of RAL with Al(OH)3 , LaCO3, Bxl, or Svl can inhibit RAL absorption into the gastrointestinal tract, and thus, the multivalent metal cation and polycationic polymer are the modifying factors that can affect RAL pharmacokinetics.

Determination of raltegravir and raltegravir glucuronide in human plasma and urine by LC–MS/MS with application in a maternal-fetal pharmacokinetic study

Raltegravir (RAL) is a HIV-integrase inhibitor recommended for treatment of HIV type 1 infection during pregnancy. The elimination of RAL to RAL glucuronide (RAL GLU) is mediated primarily by UDP glucuronosyltransferase 1A1 (UGT1A1). The present study shows the development and validation of 4 different methods for the analysis of RAL and RAL GLU in plasma and in urine samples. The methods were applied to evaluate the maternal-fetal pharmacokinetics of RAL and RAL GLU in a HIV-infected pregnant woman receiving RAL 400 mg twice daily. The sample preparation for RAL and RAL GLU analysis in 25 μL plasma and 100 μL diluted urine (10-fold with water containing 0.1% formic acid) were carried out by protein precipitation procedure. RAL and RAL GLU generate similar product mass fragments and require separation in the chromatographic system, so a suitable resolution was achieved for unchanged RAL and RAL GLU employing Ascentis Express C18 (75 × 4.6 mm, 2.7 μm) for both plasma and urine samples. The methods showed linearities at the ranges of 0.1–13.5 μg/mL RAL and 0.15–19.5 μg/mL RAL GLU in urine and 10–2000 ng/mL RAL and 2.5–800 RAL GLU in plasma. Precise and accurate evaluation showed coefficients of variation and relative errors ≤ 15%. The methods have been successfully applied in a maternal-fetal pharmacokinetic study.

Efficacy, safety and pharmacokinetics of atazanavir (200 mg twice daily) plus raltegravir (400 mg twice daily) dual regimen in the clinical setting

BackgroundUnboosted atazanavir with raltegravir has been investigated at 300mg twice daily showing frequent hyperbilirubinemia and selection of resistance-associated mutations. ObjectivesAtazanavir 200mg twice daily could increase tolerability and plasma exposure. Study designPatients on atazanavir/raltegravir (200/400 twice daily), with self-reported adherence >95% and no concomitant interacting drugs were retrospectively evaluated. Results102 patients [72.5% male, age 46.4 years (42–54), BMI 24kg/m2 (22–26)] were included. CD4+ T lymphocytes were 417 cell/μL (302–704) and 76 patients (74.5%) had HIV-RNA <50 copies/ml. After 123 weeks 18.6% patients showed virological failure and 3.9% discontinued for intolerance. Available genotypes showed selection of major integrase (7/10 patients) and protease resistance-associated mutations (5/13 patients). In patients switching with dyslipidemia (n=67) total, LDL cholesterol and triglycerides significantly decreased. Patients switching with eCRCL<60ml/min (n=27) had no significant changes while patients with eCRCL >60ml/min showed significant decrease (−9.8ml/min, p=0.003) at 96-weeks. Atazanavir and raltegravir trough concentrations were 321ng/mL (147–720) and 412ng/mL (225–695). Self-reported non-adherence (n=4) was significantly associated with virological failure (p=0.02); patients with virological success had borderline longer previous virological control (33 vs. 18 months, p=0.07). DiscussionSwitch to atazanavir/raltegravir was safe and well tolerated allowing optimal drugs’ plasma exposure. However, a concerning rate (18.6%) failed with newly selected mutations and stopped ATV/RAL because of DDI and intolerance issues or were lost to follow-up. This regimen might be considered in selected patients, without history of protease inhibitors failure or HBV infection, showing optimal adherence and prolonged suppression.

Reduced raltegravir clearance in HIV-infected liver transplant recipients: an unexpected interaction with immunosuppressive therapy?

Liver transplantation (LTx) is considered a safe procedure in selected HIV-infected patients. In this clinical setting raltegravir is the antiretroviral of choice due to its optimal tolerability and its negligible interactions with immunosuppressive drugs. We aimed at providing data on the pharmacokinetics of raltegravir in LTx recipients, on which the available information is inconclusive. In this retrospective multicentre study we characterized the pharmacokinetics of raltegravir in a consecutive series of HIV-infected LTx recipients referred to our laboratory for therapeutic drug monitoring (TDM) and compared the obtained profiles with those collected from a control group of HIV-infected patients. Seventeen HIV-infected LTx patients were considered. LTx recipients had significantly higher raltegravir AUC0-12 compared with the control group of HIV-infected patients [14 314 (11 627-19 998) versus 8795 (5218-12 954) ng·h/mL; P < 0.01]. Two LTx patients experienced moderate increments in serum transaminases, nausea and vomiting that improved after raltegravir dose reduction. High raltegravir exposure and acceptable safety profile were observed in HIV-infected LTx recipients. Our results highlight that some patients may obtain an advantage from TDM-guided raltegravir dose adjustments with potential benefits in terms of drug tolerability.

Pharmacokinetic Determinants of Virological Response to Raltegravir in the In Vitro Pharmacodynamic Hollow-Fiber Infection Model System

Daily administration (q24h) of raltegravir has been shown to be as efficacious as twice-daily administration (q12h) in the hollow-fiber infection model (HFIM) system. However, q24h regimens were not noninferior to q12h dosing in a clinical trial. We hypothesized that between-patient variability in raltegravir pharmacokinetics (PK) was responsible for the discordance in conclusions between the in vitro and in vivo studies. Hollow-fiber cartridges were inoculated with HIV-infected H9 cells and uninfected CEM-SS cells. Four cartridges received the total daily exposure (800 mg) q24h and four received half the daily exposure (400 mg) q12h. PK profiles with half-lives of 8, 4, 3, and 2 h were simulated for each dosing interval. Cell-to-cell viral spread was assessed by flow cytometry. Viral inhibition was similar between q24h and q12h dosing at the 8- and 4-h half-lives. The q24h dosing was not as efficacious as the q12h dosing when faster half-lives were simulated; a lack of viral suppression was observed at days 3 and 4 for the 2- and 3-h half-lives, respectively. The discrepancy in conclusions between the in vitro HFIM system studies and clinical trials is likely due to the large interindividual variation in raltegravir PK.

Pharmacokinetic drug-drug interaction study between raltegravir and citalopram.

Depression is the most common mental health disorder among HIV-infected patients. When treating HIV-infected patients with a selective serotonin reuptake inhibitor (SSRI), potential drug-drug interactions with antiretroviral agents have to be taken into account. We investigated the two-way pharmacokinetic drug-drug interaction and tolerability of concomitant administration of the SSRI citalopram and the HIV-1 integrase inhibitor raltegravir in healthy volunteers. An open-label, crossover, two-period trial was conducted in 24 healthy volunteers. Subjects received the following treatments: citalopram 20 mg once daily for 2 weeks followed by the combination with raltegravir 400 mg twice daily for 5 days and after a washout period raltegravir 400 mg twice daily for 5 days. Intensive steady-state pharmacokinetic blood sampling was performed. Geometric mean ratios (GMRs) of the combination versus the reference treatment and 90% CIs were calculated for the area under the plasma concentration-time curve (AUC). CYP2C19 genotyping was performed because it influences N-demethylation of citalopram to desmethylcitalopram. A total of 22 healthy volunteers completed the trial. GMRs (90% CI) were 1.00 (0.98, 1.03) for citalopram AUC0-24 h, 0.99 (0.88, 1.12) for desmethylcitalopram AUC0-24 h and 0.77 (0.50, 1.19) for raltegravir AUC0-12 h. Raltegravir plasma concentration 12 h after intake (C12 h) did not change with concomitant use of citalopram. Within each CYP2C19 phenotype subgroup the citalopram metabolite-to-parent ratio, which is a measure for metabolic enzyme activity, was not influenced by concomitant raltegravir use. Raltegravir does not influence the pharmacokinetics of citalopram and desmethylcitalopram. Citalopram did not change the pharmacokinetics of raltegravir in a clinically meaningful way. The combination was well tolerated and can be administered without dose adjustments. ClinicalTrials.gov NCT01978782.

Effect of HIV-infection and menopause status on raltegravir pharmacokinetics in the blood and genital tract

Effect of HIV-infection and menopause status on raltegravir pharmacokinetics in the blood and genital tract

Pharmacokinetics of chewed vs. swallowed raltegravir in a patient with AIDS and MAI infection: some new conflicting data.

BackgroundWhile HIV, AIDS and atypical Mycobacterium infections are closely linked, the use of Integrase-Inhibitor based cART, notably raltegravir-based regimens is more widespread. RAL should be double-dosed to 800 mg semi-daily in situation of rifampicin co-medication, because RAL is more rapidly metabolized due to rifampicin-induced Uridine-5’-diphosph- gluronosyl-transferase (UGT1A1). Recently, it was speculated that chewed RAL might lead to increased absorption, which might compensate the inductive effect of rifampicin-rapid metabolized RAL, as part of cost-saving effects in countries with high-tuberculosis prevalence and less economic power.MethodsWe report measurement of raltegravir pharmacokinetics in a 34-year AIDS-patient suffering from disseminated Mycobacterium avium infection with necessity of parenteral rifampicin treatment. RAL levels were measured with HPLC (internal standard: carbamazepine, LLQ 11 ng/ml, validation with Valistat 2.0 program (Arvecon, Germany)). For statistical analysis, a two-sided Wilcoxon signed rank test for paired samples was used.ResultsHigh intra-personal variability in raltegravir serum levels was seen. Comparable Cmax concentrations were found for 800 mg chewed and swallowed RAL, as well as for 400 mg chewed and swallowed RAL. While Cmax seems to be more dependent from overall RAL dosing than from swallowed or chewed tablets, increased AUC12 is clearly linked to higher RAL dosages per administration. Anyway, chewed raltegravir showed a rapid decrease in serum levels.ConclusionsWe found no evidence that chewed 400 mg semi-daily raltegravir in rifampicin co-medication leads to optimized pharmacokinetics. There is need for more data from randomized trials for further recommendations.

Effect of HIV Infection and Menopause Status on Raltegravir Pharmacokinetics in the Blood and Genital Tract

This study describes first dose and steady state pharmacokinetics of raltegravir (RAL) in cervicovaginal fluid (CVF) and blood plasma (BP). Three cohorts of women were enrolled sequentially in a single-site, open-label pharmacokinetic study of oral raltegravir 400 mg twice daily: HIV-negative premenopausal, HIV-infected premenopausal and HIV-infected post-menopausal women. BP and CVF were collected over 12 h after a single observed dose and at steady state. RAL concentrations were measured by HPLC-MS methods. Data are expressed as median (IQR). The ANOVA rank-sum test was used to evaluate between-group differences in steady state raltegravir exposure (area under the concentration-time curve over the 12-h dosing interval [AUC0-12 h]). First dose pharmacokinetics were obtained in HIV-negative premenopausal women and HIV-infected post-menopausal women only. The median (IQR) BP AUC0-12 h was 3,099 (985-5,959) and 4,239 (2,781-13,695) ng•h/ml and the median (IQR) CVF AUC0-12 h was 1,720 (305-5,288) and 13,797 (11,066-19,563) ng•h/ml for HIV-negative premenopausal and HIV-infected post-menopausal women, respectively. All cohorts contributed to steady-state pharmacokinetic profiles. Median (IQR) BP AUC0-12 h did not differ between the groups: 8,436 (3,080-10,111), 5,761 (1,801-10,095) and 6,180 (5,295-8,282) ng•h/ml in HIV-negative premenopausal, HIV-infected premenopausal and HIV-infected post-menopausal women, respectively. There was a trend for lower CVF AUC0-12 h among HIV-negative women 3,164 (1,156-9,540) compared to 11,465 (9,725-17,138) and 9,568 (4,271-24,306) ng•h/ml HIV-infected premenopausal and HIV-infected post-menopausal women, respectively, but this was not statistically significant (P=0.08). HIV-negative premenopausal women had a median (IQR) CVF:BP AUC0-12 h ratio of 0.46 (0.2-1.1), whereas HIV-infected premenopausal and post-menopausal women had median (IQR) CVF:BP AUC0-12 h ratio of 3.9 (1.2-6.7) and 1.4 (0.7-4.3), respectively. This is the first study to investigate RAL exposure in BP and CVF in premenopausal HIV-negative and pre- and post-menopausal HIV-infected women. These data indicate HIV and menopausal status may influence antiretroviral distribution into the female genital tract.

Pharmacokinetic study of raltegravir in HIV-infected patients with end-stage liver disease: the LIVERAL-ANRS 148 study.

The end-stage LIVER disease and RALtegravir-Agence Nationale de Recherche sur le Sida et les hépatites (LIVERAL-ANRS) 148 study aimed to evaluate the safety, efficacy, and pharmacokinetic parameters of raltegravir (RAL) in human immunodeficiency virus (HIV)-infected patients with end-stage liver disease (ESLD) (substudy 1) and to assess the lack of pharmacokinetic interaction between RAL and the immunosuppressive regimen introduced after liver transplant (substudy 2). All patients received 400 mg RAL twice daily plus 2 nucleoside reverse transcriptase inhibitors. Liver function and immunovirological parameters were monitored throughout the study. Serial blood samples were drawn to explore RAL pharmacokinetics. Plasma concentrations of protein unbound, total RAL, and RAL glucuronide were determined by liquid chromatography-tandem mass spectrometry. Ten patients with ESLD were analyzed in substudy 1. Despite an increased RAL exposure, RAL was well tolerated in all patients and no patient had to stop RAL therapy because of adverse events. Four patients were analyzed in substudy 2. No pharmacokinetic interaction was observed between cyclosporine, mycophenolic acid, and RAL. RAL tolerability was excellent; there were no episodes of acute rejection or opportunistic infection. HIV-RNA levels remained controlled and CD4 cell counts remained stable in all patients throughout the study. The results of the substudy 1 support RAL administration to patients with ESLD. Substudy 2 assesses the safety, tolerability, and efficacy of RAL therapy in HIV-infected patients after liver transplant. RAL might be recommended as a suitable antiretroviral therapy in HIV-infected patients undergoing liver transplant.

Long-term efficacy and safety of raltegravir in the management of HIV infection

Raltegravir is an integrase strand-transfer inhibitor approved for the treatment of HIV infection. It was the first medication in a novel class of antiretroviral agents to be approved for use in the United States in 2007. Raltegravir exhibits potent activity against wild-type HIV-1, but resistance development has been noted through three different pathways. It is metabolized primarily through uridine diphosphate glucuronosyltransferase 1A1 and has a single inactive glucuronide metabolite. Raltegravir is not a substrate, inhibitor, or inducer of cytochrome P450 enzymes and exhibits low potential for drug–drug interactions; however, strong uridine diphosphate glucuronosyltransferase 1A1 inhibitors or inducers can alter the pharmacokinetics of raltegravir. It is well tolerated, and the most commonly reported adverse effects include headache, nausea, and diarrhea. Serious adverse effects with raltegravir are rare but include rhabdomyolysis and severe skin and hypersensitivity reactions. It has been approved for use in both treatment-naïve and treatment-experienced patients and is a preferred first-line agent in both United States and European HIV treatment guidelines. Although initial approval was granted on 48-week data, 5-year clinical data have recently been published. This article reviews the data supporting long-term efficacy and safety of raltegravir in the treatment of HIV infection.

Raltegravir pharmacokinetics in HIV/HCV-coinfected patients with advanced liver cirrhosis (Child-Pugh C)

To describe raltegravir pharmacokinetics at steady-state in HIV/hepatitis C virus (HCV)-coinfected patients under antiretroviral (ARV) treatment with (n = 5) and without (n = 5) advanced liver cirrhosis (Child-Pugh C). This was a non-randomized, Phase I, parallel-assignment, open-label pharmacokinetic study in HIV/HCV-coinfected patients with Child-Pugh grade C hepatic cirrhosis. We recruited clinically stable HIV/HCV-coinfected adult patients with controlled HIV viraemia (<50 copies/mL) for at least 6 months. Raltegravir (400 mg twice daily) was added under fasting conditions for 5 days to the successful ritonavir-boosted protease inhibitor-based ARV regimen. The trial was registered in the ClinicalTrials.gov database (NCT01289951) (LIVERAL). Raltegravir AUC0-12 and C12 were increased 1.72-fold (90% CI, 1.02 to 2.92) and 6.58-fold (90% CI, 2.92 to14.85), respectively, in patients with advanced liver cirrhosis. No safety issues were identified and raltegravir was well tolerated by all patients. Raltegravir plasma levels are increased in HIV/HCV-coinfected patients with advanced liver cirrhosis (Child-Pugh C). Despite the higher exposure, raltegravir was safe and well tolerated.

One-Month Transplacental Pharmacokinetics of Raltegravir in a Premature Newborn after Short-Course Treatment of the HIV-1-Infected Mother

We describe the pharmacokinetics of raltegravir of a preterm newborn after short-course treatment of the mother tested HIV + the day of delivery. At age 1 month, the circulating concentration of raltegravir in the newborn was 29 ng/ml (the IC95 of RAL against HIV-1 is 15 ng/ml). Raltegravir should therefore be considered a potential transplacental postexposure prophylaxis for HIV-1 and an alternative to the use of boosted lopinavir in this context.

Raltegravir for HIV-1 infected children and adolescents: efficacy, safety, and pharmacokinetics

Raltegravir was the first HIV integrase strand-transfer inhibitor to be approved by the US FDA, in October 2007, for the treatment of HIV-1 infection in combination with other antiretroviral agents. Raltegravir can be used in treatment-naïve and -experienced patients, as well as for the treatment of multidrug-resistant infection. Raltegravir exists in two formulations: a film-coated tablet administered orally at 400 mg twice daily, and a chewable tablet administered orally at 300 mg twice daily. In 2011, raltegravir was also approved for the treatment of children and adolescents, ages 2–18 years. For adolescents (ages 12–18 years), the recommended dose is 400 mg twice daily (film-coated tablet). If children (ages 6–12 years) weigh at least 25 kg, the film-coated tablet is recommended at 400 mg twice daily. Otherwise, patients receive the chewable tablet according to weight-based dosing at approximately 6 mg/kg/dose. Studies are ongoing for children ages 4 weeks to 2 years, and preliminary efficacy and safety data are promising. This article reviews current studies on the efficacy, safety, and pharmacokinetics of raltegravir in the pediatric population and the challenges of treating HIV in children and adolescents.