[Human immunodeficiency virus and venous thromboembolism: Role of direct oral anticoagulants]

Nowadays, thanks to highly active antiretroviral therapy (HAART), human immunodeficiency virus (HIV) infection is transforming into a chronic disease. The life expectancy of people living with HIV (PWH) has increased, as well as their risk of developing several co-morbidities, in particular cardiovascular diseases. In addition, the incidence of venous thromboembolism (VTE) is increased in PWH with a 2 to 10 times higher incidence when compared to the general population. Over the last decade, direct oral anticoagulants (DOACs) have been widely used in the treatment and prevention of VTE and non-valvular atrial fibrillation. DOACs are characterized by a rapid onset of activity, a predictable response and a relatively wide therapeutic window. Nevertheless, drug interactions exist between HAART and DOACs, exposing PWH to a theoretically increased bleeding or thrombotic risk. DOACs are substrates of the transport protein P-glycoprotein and/or of isoforms of cytochromes P450 pathway, which can be affected by some antiretroviral drugs. Limited guidelines are available to assist physicians with the complexity of those drug-drug interactions. The aim of this paper is to provide an updated review on the evidence of the high risk of VTE in PWH and the place of DOAC therapy in this population.

Plasma pharmacokinetics of bedaquiline administered by nasogastric tube in an intensive care unit

We present the case of a 21-year-old man admitted to the intensive care unit with multi-organ failure due to multidrug-resistant tuberculosis (TB). TB treatment initially comprised moxifloxacin, ethambutol, linezolid and amikacin administered intravenously. Due to suspected moxifloxacin-induced liver injury, we stopped all fluoroquinolones and switched to bedaquiline (BDQ), which is only available in tablets for oral administration. Since our patient had to be fed through a nasogastric tube (NGT), BDQ was administered after being crushed and dissolved in water; drug pharmacokinetics were studied using repeated blood sampling. Therapeutic drug monitoring showed that BDQ was detectable in blood plasma with a trough concentration above the supposed efficacy threshold, suggesting that this molecule could be administered through NGT.

Management of oral antiretroviral administration in patients with swallowing disorders or with an enteral feeding tube

HIV infection has evolved into a chronic disease with comorbidities since the combination antiretroviral therapy era. Complications still occur and patients may need to be admitted to an intensive care unit. Acute respiratory failure is the first cause of these admissions, questioning the administration of solid oral dosage formulations. This issue is also observed in geriatric units where the prevalence of dysphagia is high and underestimated. The problem of antiretroviral administration is critical: altered solid oral dosage formulations and/or administration via enteral feeding tubes are sometimes the only option. The aim is to help manage antiretroviral treatment in unconscious or intubated patients and those with swallowing disorders who are hospitalized in intensive care units or geriatric units. This review provides information on the main antiretroviral regimens and on practical and legal aspects of manipulating solid oral dosage formulations and administration via enteral feeding tubes. Alternatives to the solid formulation are available for most of the 27 oral antiretrovirals available, or manufacturers provide recommendations for patients who are unable to swallow. Manipulation of solid oral dosage formulations such as crushing tablets or opening capsules and administration via feeding tubes are frequently reported but should be the last option for safety and liability issues. Before any off-label administration of a drug, physicians should consider alternatives to the solid oral dosage formulation and check whether the drug can be altered. Therapeutic monitoring is important in this particular setting as the pharmacokinetic profile of drugs is difficult to predict.

Prevalence and clinical impact of minority resistant variants in patients failing an integrase inhibitor-based regimen by ultra-deep sequencing

Background

Integrase strand transfer inhibitors (INSTIs) are recommended by international guidelines as first-line therapy in antiretroviral-naive and -experienced HIV-1-infected patients.

Objectives

This study aimed at evaluating the prevalence at failure of INSTI-resistant variants and the impact of baseline minority resistant variants (MiRVs) on the virological response to an INSTI-based regimen.

Methods

Samples at failure of 134 patients failing a raltegravir-containing (n = 65), an elvitegravir-containing (n = 20) or a dolutegravir-containing (n = 49) regimen were sequenced by Sanger sequencing and ultra-deep sequencing (UDS). Baseline samples of patients with virological failure (VF) (n = 34) and of those with virological success (VS) (n = 31) under INSTI treatment were sequenced by UDS. Data were analysed using the SmartGene platform, and resistance was interpreted according to the ANRS algorithm version 27.

Results

At failure, the prevalence of at least one INSTI-resistant variant was 39.6% by Sanger sequencing and 57.5% by UDS, changing the interpretation of resistance in 17/134 (13%) patients. Among 53 patients harbouring at least one resistance mutation detected by both techniques, the most dominant INSTI resistance mutations were N155H (45%), Q148H/K/R (23%), T97A (19%) and Y143C (11%). There was no difference in prevalence of baseline MiRVs between patients with VF and those with VS. MiRVs found at baseline in patients with VF were not detected at failure either in majority or minority mutations.

Conclusions

UDS is more sensitive than Sanger sequencing at detecting INSTI MiRVs at treatment failure. The presence of MiRVs at failure could be important to the decision to switch to other INSTIs. However, there was no association between the presence of baseline MiRVs and the response to INSTI-based therapies in our study.

Darunavir/ritonavir monotherapy at a low dose (600/100 mg/day) in HIV-1-infected individuals with suppressed HIV viraemia

Background

Darunavir/ritonavir is a potent PI with a high genetic barrier and pharmacological robustness favourably investigated as monotherapy. Whether darunavir could be dose reduced in the context of monotherapy deserves investigation.

Methods

Patients with HIV suppressed viraemia (plasma viral load <50 copies/mL for 12 months) under ART who had switched to darunavir/ritonavir monotherapy at 600/100 mg/day between 2013 and 2015 were included in this observational 48 week single-centre study. The primary outcome was the proportion of patients with virological success (defined as plasma viral load <50 copies/mL) at week 24. Secondary outcomes included treatment strategy success and resistance.

Results

Thirty-one patients were included with the following baseline characteristics [median (IQR)]: age 52 years (47-57), CD4+ 649 cells/mm3 (463-813), ART duration 16.3 years (9.2-22.3), nadir CD4+ 195 cells/mm3 (144-261) and duration of HIV suppression 7.8 years (4.8-9.7). Prior to switch, ART consisted of PI monotherapy for 28 of 31 patients [darunavir/ritonavir 800/100 mg/day (n = 26), lopinavir/ritonavir (n = 1) and atazanavir/ritonavir (n = 1)] and a triple drug regimen for 3 of 31 patients. Within the 48 weeks of follow-up, no virological failure occurred and two patients discontinued 600/100 mg of darunavir/ritonavir due to side effects at week 16 and 40, leading to a virological suppression rate of 100% (95% CI = 89-100) at weeks 24 and 48. Strategy success rates were 96.8% (95% CI = 83.3-99.9) at week 24 and 93.5% (95% CI = 78.6-99.2) at week 48. Median (IQR) Ctrough values of 800/100 mg of darunavir/ritonavir and 600/100 mg of darunavir/ritonavir were 1537 ng/mL (1286-1724) and 1255 ng/mL (873-2161), respectively.

Conclusions

A lower dose of darunavir/ritonavir used as monotherapy (600/100 mg/day) was highly effective in virologically suppressed HIV-infected patients. Further studies are needed to confirm these data.