Pharmacokinetic profiles of boosted darunavir, dolutegravir and lamivudine in aging people living with HIV

Individualizing Antiretroviral Therapy in the Older Patient

Owing to widespread availability of potent and tolerable antiretroviral therapy, life expectancy of people with human immunodeficiency virus (HIV) has significantly increased. Consequently, the population of people with HIV are ageing, with over 50% over the age of 50 years, and it is expected that 25% will be over the age of 65 years by 2030. People diagnosed with HIV at older age tend to have more advanced disease, and may already be experiencing comorbidities that will influence the choice of initial antiretroviral treatment. Despite the well described changes in pharmacokinetics associated with ageing, there are a paucity of pharmacokinetics studies of contemporary antiretroviral drugs to help guide treatment for HIV. Irrespective of this, integrase inhibitor-based regimens have been shown to have similar treatment outcomes in older and young adults and are the preferred regimens for initiation and switching therapy in older adults. Non-acquired immunodeficiency syndrome (AIDS) comorbidities are more common in people with HIV owing to chronic immune activation and inflammation even in the presence of virological suppression on antiretroviral treatment. Screening and risk assessment of comorbidities is crucial as the presence of geriatric syndrome, frailty or neurocognitive impairment may impact medication adherence. Simplification of complex regimens, both antiretroviral and comorbidity treatments, is recommended to improve adherence. Regular medication reviews under the guidance of an experienced HIV pharmacist are recommended to identify adverse drug-drug interactions and inappropriate prescribing of drugs with potential adverse effects, such as falls risk. Antiretroviral stewardship has been shown to improve patient outcomes and quality of life for ageing people with HIV.

Pharmacokinetics of Antiretroviral Drugs in Older People Living with HIV, Part II: Drugs Licensed Before 2005

BACKGROUND AND OBJECTIVE

Advances in antiretroviral therapy led to an increase in life expectancy among people living with human immunodeficiency virus (HIV). As aging is characterized by several physiological changes that can influence pharmacokinetics (PK), this systematic review aims to describe the impact of aging on the PK of antiretrovirals (ARV) approved by the Food and Drug Administration (FDA) before 2005.

METHODS

Searches were performed in BVS, EMBASE, and PubMed databases for publications until June 2024. Peer-reviewed published studies were included if they met the following criteria: adults (≥ 18 years) living with HIV; reporting at least one PK parameter or plasma concentration of any ARV approved by the US FDA before 2005 and still used in the clinic: lamivudine (3TC), emtricitabine (FTC), tenofovir disoproxil fumarate (TDF), abacavir (ABC), zidovudine (ZDV), efavirenz (EFV), nevirapine (NVP), atazanavir (ATV), lopinavir (LPV), ritonavir (RTV), tipranavir (TPV), and fosamprenavir (FPV); PK parameters stratified per age group as young (aged 18-49 years) or older (age ≥ 50 years) adults; and manuscripts published in English, Portuguese, or Spanish. All studies were evaluated for risk of bias. The review protocol was registered in the PROSPERO database (registration no. CRD42023463092).

RESULTS

Among 106 studies included, only 22 evaluated the PK of participants aged 50 years or older and only 5 studies compared the PK between young and older adults for ATV, RTV, EFV, and 3TC. Our analysis revealed an increase in minimal concentration (Cmin) values for LPV, RTV, and ATV in older adults. While increased values of the area under the curve (AUC) and maximum concentration (Cmax) were observed in older adults using ATV, 3TC, and FTC, no differences in PK were apparent between young and older adults for ABC and EFV, with no estimation possible for ZDV.

CONCLUSION

Exposure to 3TC, TDF, FTC, ATV, LPV, and RTV increases with age, while exposure to ABC and EFV appears to be unaffected. Despite the large quantity of data on PK in young adults, there is still a gap in knowledge about the effects of aging on the PK of these ARVs.

Development and Evaluation of Ontogeny Functions of the Major UDP-Glucuronosyltransferase Enzymes to Underwrite Physiologically Based Pharmacokinetic Modeling in Pediatric Populations

Uridine 5'-diphospho-glucuronosyltransferases (UGTs) demonstrate variable expression in the pediatric population. Thus, understanding of age-dependent maturation of UGTs is critical for accurate pediatric pharmacokinetics (PK) prediction of drugs that are susceptible for glucuronidation. Ontogeny functions of major UGTs have been previously developed and reported. However, those ontogeny functions are based on in vitro data (i.e., enzyme abundance, in vitro substrate activity, and so on) and therefore, may not translate to in vivo maturation of UGTs in the clinical setting. This report describes meta-analysis of the literature to develop and compare ontogeny functions for 8 primary UGTs (UGT1A1, UGT1A4, UGT1A6, UGT1A9, UGT2B7, UGT2B10, UGT2B15, and UGT2B17) based on published in vitro and in vivo studies. Once integrated with physiologically based pharmacokinetics modeling models, in vivo activity-based ontogeny functions demonstrated somewhat greater prediction accuracy (mean squared error, MSE: 0.05) compared to in vitro activity (MSE: 0.104) and in vitro abundance-based ontogeny functions (MSE: 0.129).

Pharmacokinetics of Antiretroviral Drugs in Older People Living with HIV: A Systematic Review

BACKGROUND AND OBJECTIVE

The life expectancy of people living with HIV (PLWHIV) has significantly improved in recent decades, mostly due to antiretroviral (ARV) therapy. Aging can affect the pharmacokinetics of drugs and, as a consequence, increase the risk of drug interactions and toxicity that may impact treatment. The aim of this study was to carry out a systematic review of the literature on the effect of aging on ARV pharmacokinetics.

METHODS

Searches were performed in the BVS, EMBASE and PUBMED databases until November 2022. All studies available in English, Spanish and Portuguese investigating the pharmacokinetics of ARV approved by the US Food and Drug Administration (FDA) from 2005 to 2020 were selected. Peer-reviewed publications were included if they met all criteria: adults (≥ 18 years of age) living with or without HIV; report any pharmacokinetic parameter or plasma concentration of at least one of the following ARVs: tenofovir alafenamide fumarate (TAF); doravirine (DOR), rilpivirine (RIL) and etravirine (ETR); darunavir (DRV), tipranavir (TPV) and fostemsavir (FTR); dolutegravir (DTG), raltegravir (RAL), bictegravir (BIC) and elvitegravir (EVG); maraviroc (MVC); ibalizumab (IBA); cobicistat (COBI). Pharmacokinetic parameters were reported stratified per age group: young adults (aged 18-49 years) or older (age ≥ 50 years) and all studies were evaluated for quality. The review protocol was registered in the PROSPERO database (registration number CRD42021236432).

RESULTS

Among 97 studies included, 20 reported pharmacokinetic evaluation in older individuals (age ≥ 50 years). Twenty five percent of the articles were phase I randomized clinical trials with HIV-negative participants and non-compartmental pharmacokinetic analysis presenting the parameters area under the curve (AUC) and peak drug concentration (Cmax). Seven age-stratified studies evaluated BIC, ETR, DRV, DTG, DOR and RAL. We found publications with discordant results for ETR and DTG pharmacokinetics in different age groups. DRV exposure was highly variable but modestly increased in aging PLWHIV. In contrast, no influence of age on BIC, DOR and RAL exposure was observed. A variability in pharmacokinetic parameters could be observed for the other ARVs (TAF and MVC) in different age groups.

CONCLUSION

Exposure to DRV increases modestly with age, while exposure to BIC, DOR and RAL appears to be unaffected by age. As the available evidence to confirm a potential effect of aging on ARV pharmacokinetics is limited, further studies are necessary.

Antiretroviral Drugs for Treatment and Prevention of HIV Infection in Adults: 2022 Recommendations of the International Antiviral Society-USA Panel

Importance

Recent advances in treatment and prevention of HIV warrant updated recommendations to guide optimal practice.

Objective

Based on a critical evaluation of new data, to provide clinicians with recommendations on use of antiretroviral drugs for the treatment and prevention of HIV, laboratory monitoring, care of people aging with HIV, substance use disorder and HIV, and new challenges in people with HIV, including COVID-19 and monkeypox virus infection.

Evidence Review

A panel of volunteer expert physician scientists were appointed to update the 2020 consensus recommendations. Relevant evidence in the literature (PubMed and Embase searches, which initially yielded 7891 unique citations, of which 834 were considered relevant) and studies presented at peer-reviewed scientific conferences between January 2020 and October 2022 were considered.

Findings

Initiation of antiretroviral therapy (ART) is recommended as soon as possible after diagnosis of HIV. Barriers to care should be addressed, including ensuring access to ART and adherence support. Integrase strand transfer inhibitor-containing regimens remain the mainstay of initial therapy. For people who have achieved viral suppression with a daily oral regimen, long-acting injectable therapy with cabotegravir plus rilpivirine given as infrequently as every 2 months is now an option. Weight gain and metabolic complications have been linked to certain antiretroviral medications; novel strategies to ameliorate these complications are needed. Management of comorbidities throughout the life span is increasingly important, because people with HIV are living longer and confronting the health challenges of aging. In addition, management of substance use disorder in people with HIV requires an evidence-based, integrated approach. Options for preexposure prophylaxis include oral medications (tenofovir disoproxil fumarate or tenofovir alafenamide plus emtricitabine) and, for the first time, a long-acting injectable agent, cabotegravir. Recent global health emergencies, like the SARS-CoV-2 pandemic and monkeypox virus outbreak, continue to have a major effect on people with HIV and the delivery of services. To address these and other challenges, an equity-based approach is essential.

Conclusions and Relevance

Advances in treatment and prevention of HIV continue to improve outcomes, but challenges and opportunities remain.

Reversibility of Central Nervous System Adverse Events in Course of Art

The purpose of this study is to evaluate the frequency of central nervous system adverse events (CNS-AE) on dolutegravir (DTG) and non-DTG containing ART, and their reversibility, in the observational prospective SCOLTA cohort. Factors associated with CNS-AE were estimated using a Cox proportional-hazards model. 4939 people living with HIV (PLWH) were enrolled in DTG (n = 1179) and non-DTG (n = 3760) cohorts. Sixty-six SNC-AE leading to ART discontinuation were reported, 39/1179 (3.3%) in DTG and 27/3760 (0.7%) in non-DTG cohort. PLWH naïve to ART, with higher CD4 + T count and with psychiatric disorders were more likely to develop a CNS-AE. The risk was lower in non-DTG than DTG-cohort (aHR 0.33, 95% CI 0.19−0.55, p < 0.0001). One-year follow-up was available for 63/66 PLWH with CNS-AE. AE resolution was reported in 35/39 and 23/24 cases in DTG and non-DTG cohorts, respectively. The probability of AE reversibility was not different based on ART class, sex, ethnicity, CDC stage, or baseline psychiatric disorder. At the same time, a lower rate of event resolution was found in PLWH older than 50 years (p = 0.017). In conclusion, CNS-AE leading to ART discontinuation was more frequent in DTG than non-DTG treated PLWH. Most CNS-AE resolved after ART switch, similarly in both DTG and non-DTG cohorts.

Clinical Safety Considerations of Integrase Strand Transfer Inhibitors in the Older Population Living with HIV

There are approximately 40 million people living with HIV globally, and 21% (7.9 million) are older adults (aged > 50 years) as of 2019. The average age of HIV-positive patients is predicted to increase to 58 by 2035. The favorable clinical efficacy of integrase strand transfer inhibitors has led to high rates of viral suppression and have now become the preferred agents by the AIDS guideline when initiating antiretroviral therapy. There are concerns of increasing adverse effects from HIV medications, such as integrase strand transfer inhibitors, as a result of changes in pharmacodynamic and pharmacokinetic parameters within the older population. The authors aim to describe the safety concerns of the current integrase strand transfer inhibitors based upon a narrative literature review, including recommendations for drug-drug interactions, and relevant comorbidities to consider for selection of the most appropriate integrase strand transfer inhibitor for older people living with HIV. Raltegravir is a well-tolerated option with minor adverse events; however, adherence to a twice-daily regimen may be difficult in older patients who are also taking many other medications for various comorbidities. Elvitegravir is also well tolerated with limited adverse effects, but has many drug-drug interactions that may pose problems for older patients with polypharmacy. Dolutegravir has been associated with more frequent adverse events, such as neuropsychiatric disorders.

Virologic outcomes of switching to boosted darunavir plus dolutegravir with respect to history of drug resistance

OBJECTIVE

The DUALIS study showed that switching to boosted darunavir (bDRV) plus dolutegravir (DTG; 2DR) was non-inferior to continuous bDRV plus 2 nucleoside/nucleotide reverse-transcriptase inhibitors (NRTIs; 3DR) in treatment-experienced virologically suppressed people living with HIV (PLWH). We analyzed virologic outcomes with respect to treatment history and HIV drug resistance.

DESIGN

Post hoc analysis of a randomized trial.

METHODS

Main inclusion criteria were an HIV RNA level < 50 copies/mL for ≥ 24 weeks and no resistance to integrase strand transfer inhibitors or bDRV. Resistance-associated mutations (RAMs) were interpreted using the Stanford HIVdb mutation list. Outcomes measures were 48-week virologic response (HIV RNA < 50 copies/mL, FDA snapshot) and HIV RNA ≥ 50 copies/mL (including discontinuation due to a lack of efficacy or reasons other than adverse events and HIV RNA ≥ 50 copies/mL, referred to as snapshot non-response).

RESULTS

The analysis population included 263 patients (2DR: 131, 3DR: 132): 90.1% males; median age, 48 years; CD4 + T-cell nadir < 200/µl, 47.0%; ≥ 2 treatment changes, 27.4%; NRTI, non-NRTI (NNRTI), and major protease inhibitor (PI) RAMs in 9.5%, 14.4%, and 3.4%, respectively. In patients with RAMs in the 2DR and 3DR groups, virologic response rates were 87.8% and 96.0%, respectively; the corresponding rates in those without RAMs were 85.7% and 81.8%. RAMs were unrelated to virologic non-response in either group. No treatment-emergent RAMs were observed.

CONCLUSIONS

DTG + bDRV is an effective treatment option without the risk of treatment-emergent resistance for PLWH on suppressive first- or further-line treatment with or without evidence of pre-existing NRTI, NNRTI, or PI RAMs.

TRIAL REGISTRATION

EUDRA-CT Number 2015-000360-34; registered 07 April 2015; https://www.clinicaltrialsregister.eu/ctr-search/trial/2015-000360-34/DE .

Durability of Dolutegravir-Based Regimens: A 5-Year Prospective Observational Study

This study evaluates the frequency and causes of dolutegravir (DTG) discontinuation along 5 years of follow-up, in both antiretroviral treatment (ART)-naive and experienced people living with HIV (PLWH). This is a prospective multi-center cohort study enrolling PLWH on DTG from July 2014 until November 2020. DTG-durability was investigated using the Kaplan-Meier survival curve. The Cox proportional-hazards model was used for estimating the hazard ratio (HR) of DTG discontinuation for any cause, and for adverse events (AEs). Nine hundred sixty-three PLWH were included, 25.3% were women and 28.0% were ART-naive. Discontinuations for any causes were 10.1 [95% confidence interval (95% CI) 8.9-11.5] per 100 person-years, similar in most regimens, with the apparent exception of tenofovir alafenamide/emtricitabine+DTG (p < 0.0001). In the multivariable Cox regression model, non-Caucasian ethnicity, age ≥50 years, and lower estimated glomerular filtration rate (eGFR) were associated with a higher probability of DTG interruption. The incidence rate of virological failure was 0.4 (95% CI 0.2-0.7) per 100 person-years, while the estimated discontinuation rate for AEs was 4.0 (3.2-4.9) per 100 person-years. Thirty-four DTG interruptions were due to grade ≥3 events (10 central nervous system, 6 hypersensitivity, 3 renal, 3 myalgia/asthenia, 3 abdominal pain, 2 gastrointestinal, and 7 other events). People with lower body mass index, age ≥50 years, and lower eGFR were at higher risk of AEs, while dual combinations were protective (HR 0.41 compared with abacavir/lamivudine/DTG, 95% CI 0.22-0.77). In this prospective observational study, we found high DTG durability and a low rate of virological failures. Dual therapies seemed protective toward AEs and might be considered, when feasible, a suitable option to minimize drug interactions and improve tolerability.

HIV, aging, and adherence: an update and future directions

PURPOSE OF REVIEW

To highlight recent data on antiretroviral adherence in older people living with HIV (PLWH), describe the most relevant pharmacokinetic antiretroviral studies, and identify critical research gaps in this population.

RECENT FINDINGS

Overall, studies have found that older PLWH are more likely to be adherent to antiretroviral therapy (ART). Although multiple methods to measure adherence are available (self-report, pharmacy refills, electronic device monitors, drug concentrations), there is currently no 'gold standard' adherence measure or sufficient evidence to suggest a preferred method in older patients. Recently, studies evaluating antiretroviral concentrations in hair and dried blood spots in older patients identified no major differences when compared with younger individuals. Similarly, although pharmacokinetic studies in older PLWH are scarce, most data reveal no significant pharmacokinetic differences in the aging population. Furthermore, no specific guidelines or treatment recommendations regarding ART dose modification or long-term toxicity in aging PLWH are available, mostly because of the exclusion of this population in clinical trials.

SUMMARY

How aging influences adherence and pharmacokinetics remains poorly understood. As the population of older PLWH increases, research focusing on adherence, toxicity, drug--drug interactions, and the influence of comorbidities is needed.

Relationship of polypharmacy to HIV RNA suppression in people aged ≥ 50 years living with HIV

OBJECTIVES

People living with HIV (PLWH) aged ≥ 50 years face unique challenges regarding their medication therapies, especially antiretroviral therapy (ART). Use of ARTs, along with medications for comorbidities, may lead to adverse events, drug-drug interactions (DDIs) and poor adherence. The objective of this study was to identify the number of medications above which PLWH aged ≥ 50 years are less likely to be virally suppressed and to describe other associated patient-specific risk factors.

METHODS

This was a cross-sectional study of PLWH aged ≥ 50 years, prescribed ART, and seen at least once in the Northwestern Infectious Disease Center between 1 June 2013 and 31 May 2015. Variables concerning medication use and comorbidities were collected. The primary outcome was the presence of an undetectable plasma HIV RNA level (viral load).

RESULTS

Among the 621 included patients, there was a higher percentage taking ≤ 15 medications with an undetectable plasma HIV RNA (n = 453; 80.6%) vs. patients taking > 15 medications (n = 40; 67.8%; P = 0.03). Taking > 15 medications [odds ratio (OR) 0.49; 95% confidence interval (CI) 0.26-0.96], pulmonary disease (OR 0.54; 95% CI 0.3-0.97) and CD4 T-lymphocyte count < 200 cells/μL (OR 0.39; 95% CI 0.22-0.68) decreased the odds of having an undetectable plasma HIV RNA.

CONCLUSIONS

PLWH taking > 15 medications were less likely to have an undetectable HIV RNA. Further studies are needed to evaluate the impact of overall medication economic burden on clinical outcomes among PLWH ≥ 50 years of age.

The impact of age on antiretroviral drug pharmacokinetics in the treatment of adults living with HIV

INTRODUCTION

People living with HIV (PLWH) are aging and will receive life-long treatment: despite substantial improvement in drug efficacy and tolerability, side effects still occur and they can blunt antiretroviral treatment effectiveness. Since age may affect drug exposure and may be associated with side-effects we aimed at reviewing available data on the effect of age on antiretrovirals' pharmacokinetics in adult patients.

AREAS COVERED

We searched public databases and major conference proceedings for data on age and pharmacokinetics/pharmacodynamics in PLWH. We limited our review to currently used drugs and focused on population pharmacokinetics and physiologically-based pharmacokinetic modeling studies.

EXPERT OPINION

Available evidence of a potential detrimental effect in elderly PLWH is limited by study design and small sample sizes. Careful consideration of undoubtful benefits and potential harms is advised when prescribing ARVs to geriatric patients and the knowledge of pharmacokinetics changes need to be included in the process. With the 'greying' of the pandemic we need studies with a specific focus on geriatric patients living with HIV that will consider specific phenotypes and associated changes (including sarcopenia).

Pharmacokinetic/Pharmacodynamic Modelling to Describe the Cholesterol Lowering Effect of Rosuvastatin in People Living with HIV

BACKGROUND

Rosuvastatin is a lipid-lowering agent widely prescribed in people living with HIV, which is actively transported into the liver, making it a potential victim of drug-drug interactions with antiretroviral agents.

OBJECTIVES

The aims of this study were to characterise the pharmacokinetic profile of rosuvastatin and to describe the relationship between rosuvastatin concentrations and non-high-density lipoprotein (HDL)-cholesterol levels in people living with HIV.

METHODS

A population pharmacokinetic model (NONMEM) was developed to quantify the influence of demographics, clinical characteristics and comedications on rosuvastatin pharmacokinetics. This model was combined with an indirect effect model to describe non-HDL-cholesterol measurements.

RESULTS

A two-compartment model with sequential zero- and first-order absorption best fitted the 154 rosuvastatin concentrations provided by 65 people living with HIV. None of the tested covariates significantly influenced rosuvastatin pharmacokinetics. A total of 403 non-HDL cholesterol values were available for pharmacokinetic-pharmacodynamic modelling. Baseline non-HDL cholesterol decreased by 14% and increased by 12% with etravirine and antiretroviral drugs with a known impact on the lipid profile (i.e. protease inhibitors, efavirenz, cobicistat), respectively. The baseline value was surprisingly 43% lower in people living with HIV aged 80 years compared with those aged 40 years. Simulations based on the covariate-free model predicted that, under standard rosuvastatin dosages of 5 mg and 20 mg once daily, 31% and 64% of people living with HIV would achieve non-HDL-cholesterol targets, respectively.

CONCLUSIONS

The high between-subject variability that characterises both rosuvastatin pharmacokinetic and pharmacodynamic profiles remained unexplained after the inclusion of usual covariates. Considering its limited potential for drug-drug interactions with antiretroviral agents and its potent lipid-lowering effect, rosuvastatin prescription appears safe and effective in people living with HIV with hypercholesterolaemia.

CLINICAL TRIAL REGISTRATION NO

NCT03515772.

Antiretroviral Drugs for Treatment and Prevention of HIV Infection in Adults: 2020 Recommendations of the International Antiviral Society-USA Panel

Importance

Data on the use of antiretroviral drugs, including new drugs and formulations, for the treatment and prevention of HIV infection continue to guide optimal practices.

Objective

To evaluate new data and incorporate them into current recommendations for initiating HIV therapy, monitoring individuals starting on therapy, changing regimens, preventing HIV infection for those at risk, and special considerations for older people with HIV.

Evidence Review

New evidence was collected since the previous International Antiviral (formerly AIDS) Society-USA recommendations in 2018, including data published or presented at peer-reviewed scientific conferences through August 22, 2020. A volunteer panel of 15 experts in HIV research and patient care considered these data and updated previous recommendations.

Findings

From 5316 citations about antiretroviral drugs identified, 549 were included to form the evidence basis for these recommendations. Antiretroviral therapy is recommended as soon as possible for all individuals with HIV who have detectable viremia. Most patients can start with a 3-drug regimen or now a 2-drug regimen, which includes an integrase strand transfer inhibitor. Effective options are available for patients who may be pregnant, those who have specific clinical conditions, such as kidney, liver, or cardiovascular disease, those who have opportunistic diseases, or those who have health care access issues. Recommended for the first time, a long-acting antiretroviral regimen injected once every 4 weeks for treatment or every 8 weeks pending approval by regulatory bodies and availability. For individuals at risk for HIV, preexposure prophylaxis with an oral regimen is recommended or, pending approval by regulatory bodies and availability, with a long-acting injection given every 8 weeks. Monitoring before and during therapy for effectiveness and safety is recommended. Switching therapy for virological failure is relatively rare at this time, and the recommendations for switching therapies for convenience and for other reasons are included. With the survival benefits provided by therapy, recommendations are made for older individuals with HIV. The current coronavirus disease 2019 pandemic poses particular challenges for HIV research, care, and efforts to end the HIV epidemic.

Conclusion and Relevance

Advances in HIV prevention and management with antiretroviral drugs continue to improve clinical care and outcomes among individuals at risk for and with HIV.

Clinical Pharmacokinetics of the Novel HIV-1 Non-Nucleoside Reverse Transcriptase Inhibitor Doravirine: An Assessment of the Effect of Patient Characteristics and Drug-Drug Interactions

Doravirine (MK-1439) is a novel non-nucleoside reverse transcriptase inhibitor indicated for the combination treatment of human immunodeficiency virus type-1 (HIV-1) infection. The recommended dose is 100 mg once daily. This review summarizes the pharmacokinetics of doravirine, the influence of intrinsic factors, and its drug-drug interaction (DDI) profile. Following oral administration, doravirine is rapidly absorbed (median time to maximum plasma concentration, 1-4 h) and undergoes cytochrome P450 (CYP)3A-mediated oxidative metabolism. Steady-state geometric means for AUC0-24, C24, and Cmax in individuals with HIV-1 following administration of doravirine 100 mg once daily are 37.8 μM·h, 930 nM, and 2260 nM, respectively. Age, gender, severe renal impairment, and moderate hepatic impairment have no clinically meaningful effect on doravirine pharmacokinetics, and there is limited potential for DDIs. No dose adjustment is necessary when doravirine is co-administered with strong CYP3A inhibitors. However, doravirine is contraindicated with strong CYP3A inducers (e.g., rifampin), and dose adjustment of doravirine is recommended for co-administration with the moderate CYP3A inducer, rifabutin. Included in this review are clinical trial data from phase I pharmacokinetic trials, including DDI trials and trials in participants with renal and hepatic disease but without HIV-1 infection (N = 326), as well as phase I, II, and III safety and efficacy trials in participants living with HIV-1 (N = 991). Based on these data, the pharmacokinetic profile of doravirine supports its use in diverse populations living with HIV-1 and allows co-administration with various antiretroviral agents and treatments for commonly occurring co-morbidities.

Older Age is Associated with Higher Dolutegravir Exposure in Plasma and Cerebrospinal Fluid of People Living with HIV

BACKGROUND

People living with human immunodeficiency virus are ageing under combination antiretroviral treatments but data on drug exposure in serum and cerebrospinal fluid are limited. Dolutegravir is a widely used second-generation integrase strand transfer inhibitor: conflicting data suggest that neuropsychiatric side effects may present at a higher frequency in patients with higher dolutegravir serum concentrations.

METHODS

We performed a retrospective analysis of our therapeutic drug monitoring registry identifying patients receiving once-daily dolutegravir without concomitant interacting drugs and significant clinical conditions. Data were analysed stratifying time after drug dose intake (maximum concentration 0.5-4 and trough concentration 21-27 h). Cerebrospinal fluid samples from patients enrolled in neurological studies and receiving dolutegravir were analysed for dolutegravir cerebrospinal fluid concentrations and cerebrospinal fluid-to-plasma ratios. Serum and cerebrospinal fluid concentrations were measured through validated chromatographic methods.

RESULTS

We included 207 (providing 457 serum samples) and 41 patients (providing 41 cerebrospinal fluid samples). Participants were mostly male (68.2-72.8%) of median age of 50 years (50-53 years). Non-significant changes in dolutegravir maximum concentration and trough concentration were observed with age at Spearman's test (p values > 0.05); linear logistic regression showed a significant effect of age on dolutegravir trough concentration (p = 0.0013) (Fig. 1). Dolutegravir maximum concentration [3830 ng/mL (2311-5057) vs 4230 ng/mL (2919-5272), p = 0.311] and trough concentration [838 ng/mL (362-1587) vs 966 ng/mL (460-2085), p = 0.056] were non-significantly or borderline higher in patients aged > 50 years. Cerebrospinal dolutegravir concentrations were associated with plasma concentrations (ρ = 0.374, p = 0.016) and age (ρ = 0.537, p = 0.003); cerebrospinal fluid dolutegravir concentrations (13.8 vs 7.3 ng/mL, p = 0.015) and cerebrospinal fluid-to-plasma ratios (0.57 vs 0.32%, p = 0.017] were higher in participants aged > 50 years.

CONCLUSIONS

We observed an increase in dolutegravir exposure in serum and in cerebrospinal fluid in older patients living with human immunodeficiency virus.

Effect of ageing on antiretroviral drug pharmacokinetics using clinical data combined with modelling and simulation

AIMS

The impact of ageing on antiretroviral pharmacokinetics remains uncertain, leading to missing dosing recommendations for elderly people living with human immunodeficiency virus (HIV: PLWH). The objective of this study was to investigate whether ageing leads to clinically relevant pharmacokinetic changes of antiretrovirals that would support a dose adjustment based on the age of the treated PLWH.

METHODS

Plasma concentrations for 10 first-line antiretrovirals were obtained in PLWH ≥55 years, participating in the Swiss HIV Cohort Study, and used to proof the predictive performance of our physiologically based pharmacokinetic (PBPK) model. The verified PBPK model predicted the continuous effect of ageing on HIV drug pharmacokinetics across adulthood (20-99 years). The impact of ethnicity on age-related pharmacokinetic changes between whites and other races was statistically analysed.

RESULTS

Clinically observed concentration-time profiles of all investigated antiretrovirals were generally within the 95% confidence interval of the PBPK simulations, demonstrating the predictive power of the modelling approach used. The predicted decline in drug clearance drove age-related pharmacokinetic changes of antiretrovirals, resulting in a maximal 70% [95% confidence interval: 40%, 120%] increase in antiretrovirals exposure across adulthood. Peak concentration, time to peak concentration and apparent volume of distribution were predicted to be unaltered by ageing. There was no statistically significant difference of age-related pharmacokinetic changes between studied ethnicities.

CONCLUSION

Dose adjustment for antiretrovirals based on the age of male and female PLWH is a priori not necessary in the absence of severe comorbidities considering the large safety margin of the current first-line HIV treatments.

Aging does not impact drug--drug interaction magnitudes with antiretrovirals

: The risk of drug-drug interactions (DDIs) is elevated in aging people living with HIV (PLWH) because of highly prevalent age-related comorbidities leading to more comedications. To investigate the impact of aging on DDI magnitudes between comedications (amlodipine, atorvastatin, rosuvastatin) and boosted darunavir, we conducted a clinical trial in aging PLWH aged at least 55 years. DDI magnitudes were comparable with those reported in young individuals supporting that the clinical management of DDIs in aging PLWH can be similar.

Influence of Drug-Drug Interactions on the Pharmacokinetics of Atorvastatin and Its Major Active Metabolite ortho-OH-Atorvastatin in Aging People Living with HIV

Background

People living with HIV (PLWH) are aging and experience age-related physiological changes and comorbidities. Atorvastatin is a widely prescribed lipid-lowering agent metabolized by cytochrome P450 (CYP) 3A4, whose hepatocyte uptake is facilitated by organic anion transporting polypeptide (OATP) 1B1/1B3. Inhibition or induction of this enzyme and hepatic transporter can increase or decrease atorvastatin exposure, respectively.

Objective

This study aimed to describe the pharmacokinetic profile of atorvastatin and its major metabolite, and to evaluate drug–drug interactions (DDIs) with antiretrovirals (ARVs).

Methods

The atorvastatin pharmacokinetic profile was best described by a two-compartment model with first-order absorption and elimination. Metabolite concentrations were described by considering both linear metabolism from atorvastatin and presystemic metabolism. The influence of demographic and clinical covariates on drug and metabolite pharmacokinetics was assessed using NONMEM^®. Model-based simulations were performed to evaluate the magnitude of DDIs with ARVs.

Results

Full pharmacokinetic profiles (98 atorvastatin + 62 o-OH-atorvastatin concentrations) and sparse concentrations (78 and 53 for atorvastatin and o-OH-atorvastatin, respectively) were collected in 59 PLWH. Interindividual variability was high. The coadministration of boosted ARVs decreased atorvastatin clearance by 58% and slowed down o-OH-atorvastatin formation by 88%. Atorvastatin clearance increased by 78% when coadministered with CYP3A4 inducers. Simulations revealed a 180% increase and 44% decrease in atorvastatin exposure (area under the curve) in the presence of ARVs with inhibiting and inducing properties, respectively.

Conclusion

This study showed an important interindividual variability in atorvastatin pharmacokinetics that remains largely unexplained after the inclusion of covariates. Since boosted ARVs double atorvastatin exposure, the initial dosage might be reduced by half, and titrated based on individual clinical targets.

Electronic supplementary material

The online version of this article (10.1007/s40262-020-00876-0) contains supplementary material, which is available to authorized users.