Identification of potential clinically significant drug interactions in HIV-infected patients: a comprehensive therapeutic approach

An update on drug-drug interactions in older adults living with human immunodeficiency virus (HIV)

INTRODUCTION

People with HIV are living longer due to advances in antiretroviral therapy. With improved life expectancy comes an increased lifetime risk of comorbid conditions - such as cardiovascular disease and cancer - and polypharmacy. Older adults, particularly those living with HIV, are more vulnerable to drug interactions and adverse effects, resulting in negative health outcomes.

AREA COVERED

Antiretrovirals are involved in many potential drug interactions with medications used to treat common comorbidities and geriatric conditions in an aging population of people with HIV. We review the mechanisms and management of significant drug-drug interactions involving antiretroviral medications and non-antiretroviral medications commonly used among older people living with HIV. The management of these interactions may require dose adjustments, medication switches to alternatives, enhanced monitoring, and considerations of patient- and disease-specific factors.

EXPERT OPINION

Clinicians managing comorbid conditions among older people with HIV must be particularly vigilant to side effect profiles, drug-drug interactions, pill burden, and cost when optimizing treatment. To support healthier aging among people living with HIV, there is a growing need for antiretroviral stewardship, multidisciplinary care models, and advances that promote insight into the correlations between an individual, their conditions, and their medications.

Prevalence of Potentially Clinically Significant Drug-Drug Interactions With Antiretrovirals Against HIV Over Three Decades: A Systematic Review of the Literature

BACKGROUND

Contemporary first-line antiretrovirals have considerably reduced liability for clinically significant drug-drug interactions (DDI). This systematic review evaluates the prevalence of DDI among people receiving antiretrovirals across 3 decades.

METHODS

We searched 3 databases for studies reporting the prevalence of clinically significant DDIs in patients receiving antiretrovirals published between January 1987 and July 2022. Clinically significant DDIs were graded by severity. All data extractions were undertaken by 2 independent reviewers, adjudicated by a third.

RESULTS

Of 21,665 records returned, 13,474 were duplicates. After screening the remaining 13,596 abstracts against inclusion criteria, 122 articles were included for full-text analysis, from which a final list of 34 articles were included for data synthesis. The proportion of patients experiencing a clinically significant DDI did not change over time (P = 0.072). The most frequently reported classes of antiretrovirals involved in DDIs were protease inhibitors and non-nucleoside reverse transcriptase inhibitors; of note, integrase use in the most recent studies was highly variable and ranged between 0% and 89%.

CONCLUSIONS

The absolute risk of DDIs has not decreased over the period covered. This is likely related to continued use of older regimens and an ageing cohort of patients. A greater reduction in DDI prevalence can be anticipated with broader uptake of regimens containing unboosted integrase inhibitors or non-nucleoside reverse transcriptase inhibitors.

Potential drug-drug interactions between antiretroviral drugs and comedications, including dietary supplements, among people living with HIV: A clinical survey

OBJECTIVE

Age-related comorbidities, polypharmacy and thereby the risk of potential drug-drug interactions (PDDIs) among people living with HIV (PLWH) have increased over the years. We estimated the prevalence of comedications, including dietary supplements, and evaluated PDDIs among PLWH receiving antiretroviral therapy (ART) in Denmark in an outpatient setting.

METHODS

Information on prescription medication, over-the-counter medication and dietary supplements was obtained from adult PLWH receiving ART attending two outpatient clinics in Denmark. The PDDIs were identified using the University of Liverpool's drug interaction database. Associations between PDDIs and relevant variables were compared using logistic regression models.

RESULTS

A total of 337 PLWH receiving ART with a median age of 53 years (interquartile range: 45-61) were included; 77% were male and 96% had a HIV-RNA viral load < 50 copies/mL. Twenty-six per cent of participants received five or more comedications and 56% consumed dietary supplements. Co-administration of drugs requiring dose adjustment or monitoring was identified in the medication lists of 52% of participants, and 4.5% were on drugs that should not be co-administered. Male sex [odds ratio (OR) = 1.9, 95% confidence interval (CI): 1.0-3.4], being on a protease inhibitor (OR = 4.3, 95% CI: 1.9-9.7), receiving five or more comedications (OR = 3.3, 95% CI: 1.5-7.2), taking over-the-counter medications (OR = 1.9, 95% CI: 1.1-3.3) and dietary supplements (OR = 2.0, 95% CI: 1.2-3.3) were independent predictors of PDDIs.

CONCLUSION

Potential drug-drug interactions were common among our study population Our study confirms that polypharmacy and being on a protease inhibitor-based regimen increase the risk of PDDIs considerably and highlights the importance of questioning PLWH about dietary supplement intake.

Prevalence, beliefs and impact of drug-drug interactions between antiretroviral therapy and illicit drugs among people living with HIV in Spain

Drug use implies important challenges related to HIV management, particularly due to an increased risk of potential interactions between antiretroviral therapy (ART) and illicit drugs (pDDIs). This study analyses the prevalence and severity of pDDIs among people living with HIV (PLHIV). It also explores their awareness of pDDIs and their beliefs about the toxicity that they may cause, as well as the impact of pDDIs on selected health variables. We conducted an on-line cross-sectional survey across 33 Spanish hospitals and NGOs to collect demographics and clinical data. pDDIs were checked against the Interaction Checker developed by Liverpool University. The sample of the present study was composed of 694 PLHIV who used illicit drugs. They represented 49.5% of the 1,401 PLHIV that participated in the survey. After excluding 38 participants due to lack of information on their ART or illicit drug use, 335 (51.1%) participants consuming drugs presented with some potentially significant pDDIs between their ART and illicit drugs, with a mean of 2.1±1.7 (1–10) pDDIs per patient. The drugs most frequently involved in pDDIs were cocaine, cannabis, MDMA and nitrates ("poppers"). The prevalence of pDDIs across ART regimens was: protease inhibitors (41.7%); integrase inhibitor-boosted regimens (32.1%), and non-nucleoside reverse transcriptase inhibitors (26.3%). An awareness of pDDIs and beliefs about their potential toxicity correlated positively with intentional non-adherence (p<0.0001). Participants with pDDIs exhibited a higher prevalence of intentional non-adherence (2.19±1.04 vs. 1.93±0.94; p = 0.001). The presence of pDDIs was not associated with poorer results in the clinical variables analysed. A significant proportion of PLHIV who use drugs experience pDDIs, thereby requiring close monitoring. pDDIs should be considered in the clinical management of HIV patients. Adequate information about pDDIs and indicators about how to manage ART when PLHIV use drugs could improve ART non-adherence.

Assessment of factors associated with potential drug-drug interactions in patients with tuberculosis and HIV/AIDS

INTRODUCTION:

The concomitant use of antituberculosis and antiretroviral drugs, as well as drugs to treat other diseases, can cause drug-drug interactions. This study aimed to describe potential drug-drug interactions (pDDI) in patients with TB and HIV/AIDS co-infection, as well as to analyze possible associated factors.

METHODS:

This study was performed in a reference hospital for infectious and contagious diseases in the southeastern region of Brazil and evaluated adult patients co-infected with tuberculosis and HIV/AIDS. A cross-sectional study was conducted in which sociodemographic, clinical, and pharmacotherapeutic characteristics were assessed. The pDDI were identified using the Drug-Reax software. Association analysis was performed using either a chi-squared test or a Fisher’s exact test. Correlation analysis was performed using the Spearman’s coefficient.

RESULTS:

The study included 81 patients, of whom 77 (95.1%) were exposed to pDDI. The most frequent interactions were between antituberculosis and antiretroviral drugs, which can cause therapeutic ineffectiveness and major adverse reactions. A positive correlation was established between the number of associated diseases, the number of drugs used, and the number of pDDI. An association was identified between contraindicated and moderate pDDI with excessive polypharmacy and hospitalization.

CONCLUSIONS:

We found a high frequency of pDDI, especially among those hospitalized and those with excessive polypharmacy. These findings highlight the importance of pharmacists in the pharmacotherapeutic monitoring in these patients.

High frequency of potential phosphodiesterase type 5 inhibitor drug interactions in males with HIV infection and erectile dysfunction

OBJECTIVES

We sought to determine the prevalence of phosphodiesterase type 5 inhibitor (PDE-5) mediated drug-drug interactions (DDIs) in males with HIV infection receiving antiretroviral therapy (ART) and identify factors associated with PDE-5-mediated DDIs.

METHODS

Male US Military HIV Natural History Study participants diagnosed with erectile dysfunction (ED) and having a PDE-5 inhibitor and potentially-interacting ART co-dispensed within 30 days were included. DDIs were defined according to criteria found in published guidelines and drug information resources. The primary outcome of interest was overall PDE-5 inhibitor-mediated DDI prevalence and episode duration. A secondary logistic regression analysis was performed on those with and without DDIs to identify factors associated with initial DDI episode.

RESULTS

A total of 235 male participants with ED met inclusion criteria. The majority were White (50.6%) or African American (40.4%). Median age at medication co-dispensing (45 years), duration of HIV infection (14 years), and duration of ED (1 year) did not differ between the two groups (p>0.05 for all). PDE-5 inhibitors included sildenafil (n = 124), vardenafil (n = 99), and tadalafil (n = 14). ART regimens included RTV-boosted protease inhibitors (PIs) atazanavir (n = 83) or darunavir (n = 34), and COBI-boosted elvitegravir (n = 43). Potential DDIs occurred in 181 (77.0%) participants, of whom 122 (67.4%) had multiple DDI episodes. The median DDI duration was 8 (IQR 1-12) months. In multivariate analyses, non-statistically significant higher odds of DDIs were observed with RTV-boosted PIs or PI-based ART (OR 2.13, 95% CI 0.85-5.37) and in those with a diagnosis of major depressive disorder (OR 1.74, 95% CI 0.83-3.64).

CONCLUSIONS

PDE-5-mediated DDIs were observed in the majority of males with HIV infection on RTV- or COBI-boosted ART in our cohort. This study highlights the importance of assessing for DDIs among individuals on ART, especially those on boosted regimens.

Co-medications and Drug-Drug Interactions in People Living with HIV in Turkey in the Era of Integrase Inhibitors

BACKGROUND

Long life expectancy in people living with human immunodeficiency virus (PLWH) caused an increase in comorbidities and co-medications. We aimed to analyse comedications and drug-drug interactions (DDIs) in antiretroviral therapy (ART)-naive PLWH in the era of integrase inhibitors.

METHODS

A retrospective observational study was conducted between January 2016-August 2019. Patients' characteristics and chronic co-medications were recorded. The University of Liverpool HIV drug interaction database was used for DDIs.

RESULTS

Among 745 patients, the chronic co-medication rate was 30.9%. Older age (p<0.001, OR:6.66, 95% CI: 3.86-11.49) and female gender (p=002, OR:2.25, 95%:1.14-4.44) were independently associated with co-medication. Cardiovascular system (CVS) and central nervous system (CNS) drugs were the most common co-medications. Older age patients (p<0.001, OR:12.04, 95% CI:4.63-36.71), having heterosexual (HS) contact (p=0.003, OR:3.8, 95% CI:1.57-9.22) were independently associated with CVS drugs use, while being men who have sex with men (MSM) (p=0.03, OR:2.59, 95% CI:1.11-6.03) were associated with CNS drugs use. DDIs were seen in 37.4% of patients with co-medications. Antidiabetics (23.3%), CNS (22.1%) and CVS drugs (19.8%) most commonly had DDIs. Contraindication was most commonly seen between inhaled corticosteroids and elvitegravir/cobicistat. A number of non-ART drugs, elvitegravir/cobicistat, antidiabetics, vitamins were independently associated with the presence of DDIs.

CONCLUSION

Results suggested the need for attention about co-medication in PLWH regardless of whether they are young or older. CNS drugs should be questioned more detailed in MSM, as well as CVS drugs in older HS patients. Elvitegravir/cobicistat is significantly associated with DDIs and switching to an unboosted INSTI should be considered in patients with multiple comorbidities.

Assessment of drug-drug interaction in an elderly human immunodeficiency virus population: Comparison of 3 expert databases

AIMS

Polypharmacy increase the risk of drug-drug interactions (DDIs) in the elderly population living with human immunodeficiency virus (HIV). Several expert databases can be used to evaluate DDIs. The aim of the study was to describe actual DDIs between antiretroviral drugs and comedications in an elderly population and to compare grading of the DDIs in 3 databases.

METHODS

All treatments of HIV-infected subjects aged 65 years and older were collected in 6 French HIV centres. Summary of Product Characteristic (SPC), French DDI Thesaurus (THES), and Liverpool HIV DDI website (LIV) were used to define each DDI and specific grade. DDIs were classified in yellow flag interaction (undefined grade in SPC and THES or potential weak interaction in LIV), amber flag interaction (to be considered/precaution of use in SPC and THES and potential interaction in LIV) and red flag interaction (not recommended/contraindication in SPC and THES and do not administer/contraindication in LIV).

RESULTS

Among 239 subjects included, 60 (25.1%) had at least 1 DDI for a total of 126 DDIs: 23/126 red flag DDIs were identified in 17 patients. All these 23 DDIs were identified in LIV. THES and SPC missed 6 and 1 red flag DDIs, respectively. Seven of 23 red flag DDIs were identified in the 3 databases concomitantly.

CONCLUSION

Polypharmacy is frequent in this elderly HIV population leading to DDI in a quarter of the subjects. The discrepancies between databases can be explained by differences in analysis methods. A consensus between databases would be helpful for clinicians.

Deprescribing of non-antiretroviral therapy in HIV-infected patients

PURPOSE

In recent decades, the life expectancy of HIV-infected patients has increased considerably, to the extent that the disease can now be considered chronic. In this context of progressive aging, HIV-infected persons have a greater prevalence of comorbid conditions. Consequently, they usually take more non-antiretroviral drugs, and their drug therapy are more complex. This supposes a greater risk of drug interactions, of hospitalization, falls, and death. In the last years, deprescribing has gained attention as a means to rationalize medication use.

METHODS

Review of the different therapeutic approach that includes optimization of polypharmacy and control and reduction of potentially inappropriate prescription.

RESULTS

There are several protocols for systematizing the deprescribing process. The most widely used tool is the Medication Regimen Complexity Index, an index validated in HIV-infected persons. Anticholinergic medications are the agents that have been most associated with major adverse effects so, various scales have been employed to measure it. Other tools should be employed to detect and prevent the use of potentially inappropriate drugs. Prioritization of candidates should be based, among others, on drugs that should always be avoided and drugs with no justified indication.

CONCLUSIONS

The deprescribing process shared by professionals and patients definitively would improve management of treatment in this population. Because polypharmacy in HIV-infected patients show that a considerable percentage of patients could be candidates for deprescribing, we must understand the importance of deprescribing and that HIV-infected persons should be a priority group. This process would be highly feasible and effective in HIV-infected persons.

The Incidence and Severity of Drug Interactions Before and After Antiretroviral Therapy Simplification in Treatment-Experienced Patients With HIV Infection

Background: Current guidelines advocate for antiretroviral therapy (ART) simplification in patients on complicated regimens. Simplifying ART improves patient adherence and quality of life, but changes in drug interactions (DIs) are uncertain. Objective: This study assessed changes in DIs following ART simplification in patients with HIV. Methods: This was an observational, retrospective cohort study of patients attending an urban HIV clinic. Patients were included if they had ART simplification (a decreased number of daily tablets) and ≥1 concomitant medication (CM). Total DI scores were generated for each patient pre-ART simplification and post-ART simplification using an online DI database. Each ART-CM pair labeled as "do not co-administer" was given a score of 2, "potential interaction" a score of 1, or "no interaction" a score of 0. Differences in total DI scores following simplification were analyzed with a Wilcoxon Signed-Rank test. Predictors of DI score reductions were examined with linear regression. Results: A total of 99 patients were included. Their median age was 54 years, and 79% were male. The median durations of HIV infection and ART were 16 and 10 years, respectively. Patients were receiving an average of 4.5 CMs. Median interaction scores presimplification and postsimplification were 3 (interquartile range [IQR], 1-6) and 1 (IQR, 0-2) respectively (P < 0.001). Predictors of score reductions were the patient's number of CMs, discontinuing a protease inhibitor, and switching to a dolutegravir-based regimen. Conclusion and Relevance: ART simplification decreased the incidence of DIs in this analysis of patients with advanced age who had ART experience and polypharmacy.

Risk and Cost Associated With Drug-Drug Interactions Among Aging HIV Patients Receiving Combined Antiretroviral Therapy in France

Background

We aimed to describe the frequency, risk factors, and costs attributable to drug–drug interactions (DDIs) among an aging French HIV population.

Methods

We conducted a retrospective cohort study using French nationwide health care e-records: the SNIIRAM database. People living with HIV (PLWH) aged >65 years and receiving combined antiretroviral treatment (cART) during 2016 were included. A DDI was defined as “These drugs should not be co-administered,” represented by a red symbol on the University of Liverpool website. Attributable DDIs’ cost was defined as the difference between individuals with and without DDIs regarding all reimbursed health care acts.

Results

Overall, 9076 PLWH met the study criteria. Their baseline characteristics were: mean age, 71.3 ± 4.9 years; 25% female; median HIV duration (interquartile range [IQR]), 16.2 (9.5–20.3) years; median comorbidities (IQR), 2 (1–3). During 2016, they received a median (IQR) of 14 (9–21) comedications (non-cART), and 1529 individuals had at least 1 DDI (16.8%; 95% confidence interval [CI], 16.1–17.6). In multivariate analysis, raltegravir or dolutegravir plus 2 nucleoside reverse-transcriptase inhibitors (NRTIs) significantly and independently reduced the risk of DDIs (adjusted odds ratio [aOR], 0.02; 95% CI, 0.005–0.050; P < .0001) compared with non-nucleoside reverse-transcriptase inhibitor plus 2 NRTIs, whereas cART with boosted agents (protease inhibitors or elvitegravir) significantly increased the risk (aOR, 4.12; 95% CI, 3.34–5.10; P < .0001). Compared with propensity score–matched PLWH without DDIs, the presence of DDIs was associated with a $2693 additional cost per year (P < .0001).

Conclusions

The presence of DDIs is frequent and significantly increases health care costs in the aging population of PLWH.

Recognition of possible risk factors for clinically significant drug-drug interactions among Indian people living with HIV receiving highly active antiretroviral therapy and concomitant medications

BACKGROUND

Greatest challenges for clinician is to recognize risk factors for clinically significant drug interactions (CSDIs). There is a lack of awareness about CSDIs among healthcare professionals in India.

OBJECTIVE

To recognize all possible risk factors for drug-drug interactions (DDIs) and to identify clinically significant drug interactions (CSDIs), the prevalence, pattern of occurrence of DDIs in People Living with HIV (PLW-HIV) receiving highly active antiretroviral therapy (HAART) and concomitant medications.

METHODS

A retrospective medical record review was carried out by clinical pharmacist with ethics committee approval. Case files of HIV patients receiving HAART with concomitant medications were analyzed for CSDIs using University of Liverpool drug interaction database and CSDIs were classified based on red flag indication (RFI) or contraindicated drug-drug interaction (XDDIs) and orange flag indication (OFI) or DDIs that needs close monitoring. Patients with DDIs (cases) and patients without DDIs (controls) were compared with Chi-square tests. P value <0.05 was considered as statistically significant.

RESULTS

A total of 240 HIV patients' cases were screened. Out of which 267 DDIs were reported in 107 patients. Prevalence of DDIs was higher in male 71 (66.4%) compared to female 36 (33.6%). On zero-inflated poisson regression analysis, factors of polypharmacy, opportunistic infections, comorbid condition like Ischemic heart disease, respiratory tract infections, and psychiatric disorder were found to be predictors of high risk factors for DDIs to HAART. Fourteen XDDIs with RFI and two hundred fifty three DDIs with OFI were reported. XDDIs were atazanavir with fluconazole 4 (28.6%), ritonavir with fluconazole 4 (28.6%), nevirapine with rifampicin 2 (14.4%), ritonavir with quetiapine, atazanavir with pantoprazole. Pharmacokinetic DDIs were highest 238 (89.1%). Sixteen DDIs were reported in a single patient. The majority 97 (90.6%) patients had developed ≤5 DDIs, 8 (7.5%) developed six to eleven DDIs. The highest DDIs were reported with efavirenz 49 (18.4%) and zidovudine 44 (16.5%) based HAART regimen.

CONCLUSION

In India, with the increasing access to HAART usage, Clinician must focus to pay attention to recognize possible risk factors for CSDIs associated with HAART regimen and strictly to avoid "Red Flag Indication combinations" while prescribing so as to prevent CSDIs.

Preventable adverse drug events in critically ill HIV patients: Is the detection of potential drug-drug interactions a useful tool?

OBJECTIVES

The aim of this study was to develop a strategy to identify adverse drug events associated with drug-drug interactions by analyzing the prescriptions of critically ill patients.

METHODS

This retrospective study included HIV/AIDS patients who were admitted to an intensive care unit between November 2006 and September 2008. Data were collected in two stages. In the first stage, three prescriptions administered throughout the entire duration of these patients' hospitalization were reviewed, with the Micromedex database used to search for potential drug-drug interactions. In the second stage, a search for adverse drug events in all available medical, nursing and laboratory records was performed. The probability that a drug-drug interaction caused each adverse drug events was assessed using the Naranjo algorithm.

RESULTS

A total of 186 drug prescriptions of 62 HIV/AIDS patients were analyzed. There were 331 potential drug-drug interactions, and 9% of these potential interactions resulted in adverse drug events in 16 patients; these adverse drug events included treatment failure (16.7%) and adverse reactions (83.3%). Most of the adverse drug reactions were classified as possible based on the Naranjo algorithm.

CONCLUSIONS

The approach used in this study allowed for the detection of adverse drug events related to 9% of the potential drug-drug interactions that were identified; these adverse drug events affected 26% of the study population. With the monitoring of adverse drug events based on prescriptions, a combination of the evaluation of potential drug-drug interactions by clinical pharmacy services and the monitoring of critically ill patients is an effective strategy that can be used as a complementary tool for safety assessments and the prevention of adverse drug events.

A Pharmacist-Led Program to Evaluate and Reduce Polypharmacy and Potentially Inappropriate Prescribing in Older HIV-Positive Patients

OBJECTIVE

The goal of this pharmacist-led study was to utilize two validated instruments, Beers Criteria and Screening Tool of Older Persons' Potentially Inappropriate Prescriptions (STOPP), to assess potentially inappropriate prescribing (PIP) in older patients infected with the human immunodeficiency virus (HIV) and evaluate pharmacist interventions.

DESIGN

Prospective randomized interventional trial.

SETTING

Large urban clinic providing interdisciplinary primary and HIV care for ~2700 HIV-positive publicly insured patients.

DATA SOURCE

A computerized electronic record search was conducted for all patients who met the two search criteria: 50 years and older, and a primary care appointment within the last 12 months.

PATIENTS

After identification of 857 patients meeting the search criteria, 324 patients were randomly selected and contacted, resulting in 248 patients assessed.

MEASUREMENTS AND MAIN RESULTS

Patients had a mean age of 58 years, 71% male, 44% white, and a mean CD4 count of 536 cells/mm³ . Common comorbidities included hypertension (56%), depression (52%), asthma/chronic obstructive pulmonary disease (48%), dyslipidemia (39%), coronary artery disease (27%), and diabetes (22%). Patients sampled were prescribed a mean of 11.6 ± 5.7 concomitant medications (excluding antiretrovirals) with 35% receiving at least 16 medications. PIP was identified in 54% and 63% of patients using the STOPP and Beers Criteria, respectively. Twenty-five contraindicated drug interactions were identified in 20 patients. After the pharmacist visit, at least 69% of patients had at least one medication discontinued with almost 10% having six or more medications discontinued. More than 40% of patients had at least one Beers or STOPP criteria that required immediate correction by the pharmacist.

CONCLUSIONS

Results suggest that targeting individuals with 11 or more chronic medications would have the highest yield and greatest impact. Pharmacist-led review of medication prescribing using Beers and STOPP criteria revealed a large number of PIP, many amenable to immediate clinical pharmacist intervention.

A review of drug-drug interactions in older HIV-infected patients

INTRODUCTION

The number of older HIV-infected people is growing due to increasing life expectancies resulting from the use of antiretroviral therapy (ART). Both HIV and aging increase the risk of other comorbidities, such as cardiovascular disease, osteoporosis, and some malignancies, leading to greater challenges in managing HIV with other conditions. This results in complex medication regimens with the potential for significant drug-drug interactions and increased morbidity and mortality. Area covered: We review the metabolic pathways of ART and other medications used to treat medical co-morbidities, highlight potential areas of concern for drug-drug interactions, and where feasible, suggest alternative approaches for treating these conditions as suggested from national guidelines or articles published in the English language. Expert commentary: There is limited evidence-based data on ART drug interactions, pharmacokinetics and pharmacodynamics in the older HIV-infected population. Choosing and maintaining effective ART regimens for older adults requires consideration of side effect profile, individual comorbidities, interactions with concurrent prescriptions and non-prescription medications and supplements, dietary patterns with respect to dosing, pill burden and ease of dosing, cost and affordability, patient preferences, social situation, and ART resistance history. Practitioners must remain vigilant for potential drug interactions and intervene when there is a potential for harm.

Comparing the Frequencies of Contraindicated Drug-Drug Interactions Between Differing Antiretroviral Regimens in HIV-Infected Patients

BACKGROUND

HIV-infected patients receiving antiretroviral therapy (ART) are at risk for contraindicated drug-drug interactions (XDDIs).

OBJECTIVE

This study compared the frequency of XDDIs between different types of ART regimens.

METHODS

A retrospective cohort study was performed among adult HIV-infected patients receiving care at either the Upstate New York Veterans' Healthcare Administration or the University of New Mexico Truman Health Services between 2000 and 2013. The cohort consisted of patients receiving traditional ART regimens composed of 2 nucleoside reverse transcriptase inhibitors plus either a nonnucleoside reverse transcriptase inhibitor (NNRTI), a protease inhibitor (PI), or an integrase strand transfer inhibitor (INSTI). The primary outcome was the presence of XDDIs. Lexi-Interact was used to define XDDIs.

RESULTS

Of the 1329 patients who met inclusion criteria, 45.7%, 34.2%, and 20.1% were receiving an NNRTI-, PI-, or INSTI- based ART regimen, respectively. Among the 128 (9.6%) patients with an XDDI, more than half (53.9%) had an interaction involving ART. The presence of XDDIs was highest for PI-based regimens (16.3%) compared with INSTI- (7.9%) and NNRTI-based (5.4%) regimens; P < 0.001. The variables independently associated with XDDIs were ART regimen type (prevalence ratio [PR] = 1.91; 95% CI = 1.51-2.40, P < 0.001), use of ≥6 non-HIV medications (PR = 5.84; 95% CI = 3.92-8.71, P < 0.001), and age ≥40 years (PR = 1.62; 95% CI = 0.92-2.86, P = 0.10).

CONCLUSION

The probability of XDDIs varies as a function of ART regimen type, advanced age, and use of multiple non-HIV medications.

Early neuropsychological adverse events after switching from PI/r to dolutegravir could be related to hyperthyroidism in patients under levothyroxine

We report two patients who had taken levothyroxine at the same dose for several years and who had stable thyroid stimulating hormone (TSH) levels, and who developed clinical and biological hyperthyroidism following switch from ritonavir-boosted protease inhibitors (PIs) to dolutegravir-based HAART. Levothyroxine is metabolized by deiodination and glucuronidation and the induction of glucuronidation by ritonavir leads to an increased elimination of levothyroxine and a necessity of higher daily doses. Patients who switch from ritonavir-boosted PIs to antiretroviral drugs-based HAART with minimal drug-interaction such as dolutegravir, may require an adjustment in their dose of levothyroxine in order to prevent hyperthyroidism due to impaired elimination of levothyroxine without ritonavir.

Deep sequencing for HIV-1 clinical management

The emerging HIV-1 resistance epidemic is threatening the impressive global advances in HIV-1 infection treatment and prevention achieved in the last decade. Next-generation sequencing is improving our ability to understand, diagnose and prevent HIV-1 resistance, being increasingly cost-effective and more accessible. However, NGS still faces a number of limitations that need to be addressed to enable its widespread use. Here, we will review the main NGS platforms available for HIV-1 diagnosis, the factors affecting the clinical utility of NGS testing and the evidence supporting -or not- ultrasensitive genotyping over Sanger sequencing for routine HIV-1 diagnosis. Now that global HIV-1 eradication might be within our reach, making NGS accessible also to LMICs has become a priority. Reductions in sequencing costs, particularly in library preparation, and accessibility to low-cost, robust but simplified automated bioinformatic analyses of NGS data will remain essential to end the HIV-1 pandemic.

Ageing with HIV: do comorbidities and polymedication drive treatment optimization?

OBJECTIVES

The aim of the study was to describe the ageing HIV-infected population (> 50 years old) and their current antiretroviral therapy (ART), comorbidities and coprescriptions in France in 2013 and to compare them to the younger population.

METHODS

A retrospective analysis of a prospectively collected database was performed. The characteristics of patients receiving ART as well as their current ART and their numbers of comorbidities and comedications at the censoring date (1 July 2013) were compared between patients ageing with HIV infection, patients who seroconverted while ageing, and younger patients.

RESULTS

We compared 10 318 ageing patients [median age 56 years; 25% interquartile range (IQR) 53-62 years] with 13 302 younger patients (median age 42 years; 25% IQR 36-47 years). The ageing patients were more frequently male than the younger patients (77 vs. 65%). Among the ageing patients, 7025 were diagnosed with HIV infection before 2000 and represented a distinct group, the 'experienced ageing' group, by comparison with the 'recently diagnosed ageing' group. Triple therapy containing a boosted protease inhibitor was used in 28.2% of the patients (vs. 39% and 36% of the younger and "recently diagnosed ageing" groups, respectively); a nonnucleoside reverse transcriptase inhibitor in 27% (vs. 33% and 38%, respectively), an integrase strand transfer inhibitor (INSTI) in 9% (vs. 7% and 9%, respectively), and another regimen (fewer or more than three drugs) in 35.8% (vs. 21% and 16.5%, respectively). "Experienced ageing" patients typically had one or more comorbidities (62.1%) and were receiving at least one comedication (71%). Central nervous system (CNS) agents (prescribed in 44.6% of the "experienced ageing" patients) and antilipidaemics (in 44.2%) were the most frequently prescribed comedications. INSTIs were used in 23% of the population and were used significantly more often in patients with comorbidities and coprescriptions. For all comparisons, P < 0.0001.

CONCLUSIONS

In ageing HIV-infected patients, especially those with a long history of HIV infection, comorbidities and coprescriptions are highly prevalent.

Free software to analyse the clinical relevance of drug interactions with antiretroviral agents (SIMARV®) in patients with HIV/AIDS

BACKGROUND

Highly active antiretroviral therapy has extended the expected lifespan of patients with HIV/AIDS. However, the therapeutic benefits of some drugs used simultaneously with highly active antiretroviral therapy may be adversely affected by drug interactions.

OBJECTIVE

The goal was to design and develop a free software to facilitate analysis, assessment, and clinical decision making according to the clinical relevance of drug interactions in patients with HIV/AIDS.

METHODS

A comprehensive Medline/PubMed database search of drug interactions was performed. Articles that recognized any drug interactions in HIV disease were selected. The publications accessed were limited to human studies in English or Spanish, with full texts retrieved. Drug interactions were analyzed, assessed, and grouped into four levels of clinical relevance according to gravity and probability. Software to systematize the information regarding drug interactions and their clinical relevance was designed and developed.

RESULTS

Overall, 952 different references were retrieved and 446 selected; in addition, 67 articles were selected from the citation lists of identified articles. A total of 2119 pairs of drug interactions were identified; of this group, 2006 (94.7%) were drug-drug interactions, 1982 (93.5%) had an identified pharmacokinetic mechanism, and 1409 (66.5%) were mediated by enzyme inhibition. In terms of clinical relevance, 1285 (60.6%) drug interactions were clinically significant in patients with HIV (levels 1 and 2). With this information, a software program that facilitates identification and assessment of the clinical relevance of antiretroviral drug interactions (SIMARV^®) was developed.

CONCLUSIONS

A free software package with information on 2119 pairs of antiretroviral drug interactions was designed and developed that could facilitate analysis, assessment, and clinical decision making according to the clinical relevance of drug interactions in patients with HIV/AIDS.