Antiretroviral Drug Interactions Research Articles

Clinical Relevance of Drug Interactions in People Living with Human Immunodeficiency Virus on Antiretroviral Therapy-Update 2022: Systematic Review.

The clinical outcomes of antiretroviral drugs may be modified through drug interactions; thus, it is important to update the drug interactions in people living with HIV (PLHIV). To update clinically relevant drug interactions in PLHIV on antiretroviral therapy with novel drug interactions published from 2017 to 2022. A systematic review in Medline/PubMed database from July 2017 to December 2022 using the Mesh terms antiretroviral agents and drug interactions or herb-drug interactions or food-drug interactions. Publications with drug interactions in humans, in English or Spanish, and with full-text access were retrieved. The clinical relevance of drug interactions was grouped into five levels according to the gravity and probability of occurrence. A total of 366 articles were identified, with 219 (including 87 citation lists) were included, which allowed for the identification of 471 drug interaction pairs; among them, 291 were systematically reported for the first time. In total 42 (14.4%) and 137 (47.1%) were level one and two, respectively, and 233 (80.1%) pairs were explained with the pharmacokinetic mechanism. Among these 291 pairs, protease inhibitors (PIs) and ritonavir/cobicistat-boosted PIs, as well as integrase strand transfer inhibitors (InSTIs), with 70 (24.1%) and 65 (22.3%) drug interaction pairs of levels one and two, respectively, were more frequent. In PLHIV on antiretroviral therapy, we identify 291 drug interaction pairs systematically reported for the first time, with 179 (61.5%) being assessed as clinically relevant (levels one and two). The pharmacokinetic mechanism was the most frequently identified. PIs, ritonavir/cobicistat-boosted PIs, and InSTIs were the antiretroviral groups with the highest number of clinically relevant drug interaction pairs (levels one and two).

Evolving patterns of antiretroviral drug interactions in people with HIV in British Columbia, Canada.

To characterize the annual prevalence of antiretroviral/nonantiretroviral drug interactions in relation to antiretroviral therapy (ART)-prescribing patterns, and to describe drug interaction-related ART changes. This cohort study included ART-treated adults in British Columbia, Canada between 01 January 2010 and 31 December 2016. Medication dispensing records were abstracted from a population-based, linked administrative-health dataset and used to identify antiretroviral-comedication drug interactions ('caution'/'avoid' drug interactions in HIV-focused drug interaction checkers). We identified temporal trends in annual drug interaction prevalence and quantified the association between taking higher drug interaction-risk ART and receiving nonrecommended antiretroviral-comedication combinations using Poisson regression models, modified for binary outcomes and correlated data. Clinician-reported, drug interaction-related ART changes and associated adverse events were abstracted from an HIV drug treatment registry and summarized descriptively. Among 8571 ART-treated adults who received nonantiretroviral comedications, prevalence of having any drug interaction or receiving nonrecommended drug combination(s) significantly declined from 85 to 71% and 5.6 to 3.2%, respectively, between 2010 and 2016 ( P < 0.001). This paralleled a shift from higher drug interaction-risk ART (e.g. ritonavir/cobicistat-boosted protease inhibitors) to lower drug interaction-risk ART (e.g. unboosted integrase inhibitors). Risk of receiving a nonrecommended antiretroviral-comedication combination was greater for persons taking higher vs. lower drug interaction-risk ART [adjusted risk ratio (aRR) 3.12, 95% confidence interval (CI) 2.24-4.35]. Boosted antiretroviral-inhaled corticosteroid drug interactions accounted for the most commonly dispensed, nonrecommended drug combinations, and the most commonly reported drug interaction-related adverse events (adrenal insufficiency). The prevalence of antiretroviral-comedication drug interactions is declining as ART shifts towards antiretrovirals with lower drug interaction potential but nonrecommended drug combinations remain a concern. Healthcare providers should screen for drug interactions whenever drugs are prescribed or dispensed.

Antiretroviral Treatment and Antihypertensive Therapy.

The presence of hypertension among the population with human immunodeficiency virus (HIV) has become a new threat to the health and well-being of people living with this disease, in particular, among those who received antiretroviral therapy. The estimated prevalence of high blood pressure in HIV-infected patients is significantly higher than the rate observed in HIV-uninfected subjects. The approach to the HIV-positive patient requires the assessment of individual cardiovascular risk and its consideration when designing the individualized target. On the other hand, the numerous pharmacological interactions of antiretroviral (ARV) drugs are essential elements to take into account. Serum levels of any kind of antihypertensive drugs may be influenced by the coadministration of protease inhibitors, non-nucleoside reverse transcriptase inhibitor, or other antiretroviral. Similarly, plasma concentrations of antiretroviral drugs can be increased by the concomitant use of calcium channel blockers or diuretics. In this regard, the treatment of high blood pressure in HIV patients should be preferentially based on ACE inhibitors or thiazide/thiazide-like diuretics or their combination.

Pharmacological considerations for the treatment of COVID-19 in people living with HIV (PLWH)

ABSTRACT Introduction When coronavirus infectious disease-2019 (COVID-19) blew up, ill-fated auguries on the collision between COVID-19 and the human immunodeficiency virus (HIV) epidemics loomed. Areas covered Data from observational studies suggest similar incidence attacks of SARS-CoV-2 infection in people living with HIV (PLWH) and HIV-uninfected populations. The mortality rate of COVID-19 is similar in both populations too. The authors discuss the role of combination antiretroviral therapy (cART) in preventing infection or reducing COVID-19 severity. They also discuss the pharmacological interventions for COVID-19 in PLWH. Expert opinion Management of COVID-19 in PLWH is no different from the general population. It should be based on careful supportive care, emphasizing lung-protective ventilation, and wise pharmacological interventions. The antiviral drug remdesivir and dexamethasone are the only pharmacological interventions with clinical benefit for COVID-19, whereas anticoagulation may prevent thrombotic complications. The experience with using these drugs in PLWH is limited, which prevents from rendering well-founded conclusions. Until more data on COVID-19 in PLWH become available, the best weapons within our reach are sound supportive care and sensible use of RDV and dexamethasone, bearing in mind the potential for drug–drug interactions of most corticosteroids and antiretroviral drugs.

Multidrug-Resistant Tuberculosis in Patients with Human Immunodeficiency Virus. Management Considerations within High-resourced Settings.

The management of multidrug-resistant tuberculosis (MDR TB) is notably complex among patients with human immunodeficiency virus (HIV). TB treatment recommendations typically include very little information specific to HIV and MDR TB, which often is derived from clinical trials conducted in low-resource settings. Mortality rates among patients with HIV and MDR TB remain high. We reviewed the published literature and recommendations to synthesize possible patient management approaches demonstrated to improve treatment outcomes in high-resourced countries for patients with MDR TB and HIV. Approaches to diagnostic testing, impact and timing of antiretroviral therapy on mortality, anti-MDR TB and antiretroviral drug interactions, and the potential role for short-course MDR TB therapy are examined. The combination of antiretroviral therapy with expanded TB drug therapy, along with the management of immune reconstitution inflammatory syndrome, other potential HIV-associated opportunistic diseases, and drug toxicities, necessitate an integrated multidisciplinary patient care approach using public health case management and provider expertise in drug-resistant TB and HIV management.

The clinical relevance of drug interactions in patients with human immunodeficiency virus infection: update 2015-2017

The pharmacokinetics of anti-retrovirals (ARVs) can be modified by other concomitant medicinal products. It is timely to update the interactions between new ARVs and drugs of chronic use to maintain therapeutic success. To update information about drug interactions in patients with HIV/AIDS on antiretroviral therapy. Comprehensive literature review in MEDLINE/PubMed database from January of 2015 to June of 2017, using the Mesh terms: Anti-retroviral agents and drug interactions or herb-drug interactions or food-drug interactions. Publications with drug interactions in humans, in English or Spanish, and with full text were retrieved. Additionally, citation lists from identified articles were reviewed. The study inclusion was assessed by three independent researchers and by consensus among them when was necessary. Clinical relevance of drug interaction was grouped into levels according to seriously and probability of occurrence. 466 articles were identified; full text was accessed in 444. Of these, 164 provided interactions, which allowed the identification of a total of 534 pairs of drug interactions. The interactions that presented a higher risk of generating safety and effectiveness problems were 308 (57.7%) of level 2 and 35 (6.6%) of level 1. We identify 534 new pairs of drug interactions, of which 308 (64.2%) are the most clinically relevant.

THE IMPACT PROJECT: IMPROVING THE IMPACT OF EXISTING MALARIA PRODUCTS – ACTS

BackgroundThe antimalarial dihydroartemisinin-piperaquine (DHA-PPQ) is one of the recommended drugs to treat uncomplicated Plasmodium falciparum malaria. However, DHA-PPQ has a relatively narrow, poorly defined therapeutic dose range and it is...

Cardiopatía isquémica en el VIH: profundizando en el conocimiento del riesgo cardiovascular

Although the incidence of cardiovascular diseases classically associated with human immunodeficiency virus (HIV) has decreased considerably with antiretroviral therapy, cardiovascular risk, and especially ischemic heart disease, are higher in HIV-infected patients than in uninfected individuals. This is due to the interaction of patient-dependent factors with virus-dependent factors, as well as factors associated with antiretroviral therapy. With increasing of life expectancy and the chronicity of HIV infection, cardiovascular disease has emerged as an important cause of morbidity and mortality in HIV patients. In developed countries, the most common cardiovascular manifestation of HIV is ischemic heart disease. Currently, it is not uncommon to find HIV patients with acute coronary syndrome and, given the important pharmacokinetic interactions of antiretroviral drugs, it is important to know which cardiovascular treatments are safe in this group of patients. The ideal approach would be to mitigate the cardiovascular risk in HIV patients with specific primary prevention measures. All these issues are discussed in this review, which aims to aid clinical cardiologists faced with HIV patients with ischemic heart disease or with high cardiovascular risk in daily clinical practice.Full English text available from:www.revespcardiol.org/en

Ischemic Heart Disease in HIV: An In-depth Look at Cardiovascular Risk

Although the incidence of cardiovascular diseases classically associated with human immunodeficiency virus (HIV) has decreased considerably with antiretroviral therapy, cardiovascular risk, and especially ischemic heart disease, are higher in HIV-infected patients than in uninfected individuals. This is due to the interaction of patient-dependent factors with virus-dependent factors, as well as factors associated with antiretroviral therapy. With increasing of life expectancy and the chronicity of HIV infection, cardiovascular disease has emerged as an important cause of morbidity and mortality in HIV patients. In developed countries, the most common cardiovascular manifestation of HIV is ischemic heart disease. Currently, it is not uncommon to find HIV patients with acute coronary syndrome and, given the important pharmacokinetic interactions of antiretroviral drugs, it is important to know which cardiovascular treatments are safe in this group of patients. The ideal approach would be to mitigate the cardiovascular risk in HIV patients with specific primary prevention measures. All these issues are discussed in this review, which aims to aid clinical cardiologists faced with HIV patients with ischemic heart disease or with high cardiovascular risk in daily clinical practice.

The clinical relevance of drug interactions in patients with human immunodeficiency virus infection: update 2009-2014

To update information about drug interactions in patients with HIV/AIDS. Comprehensive literature review in MEDLINE/PubMed database from May of 2009 to December of 2014, using the Mesh terms: Anti-retroviral agents and drug interactions or herb-drug interactions or food-drug interactions. Publications with drug interactions in humans, in English or Spanish, and with full text were retrieved. Additionally, citation lists from identified articles were reviewed. The study inclusion was assessed by three independent researchers and by consensus among them when was necessary. Clinical relevance of drug interaction was grouped into four levels according to seriously and probability of occurrence. Global, 546 different references were retrieved and 243 were selected. In addition 11 further manuscripts were identified in the references of the included articles. Overall, 935 pairs of drug interactions were identified, 95.7% pharmacokinetic (823 by enzyme induction or inhibition and 67 by changes in bioavailability). Of the 935 pairs of drug interactions, 402(43%) were classified as levels 1 or 2. The most clinically relevant antiretroviral drug interactions are due to pharmacokinetic mechanism, mainly induction or enzyme inhibition, according to previous reviews, the protease inhibitors remain as the antiretrovirals with the highest number of clinical relevant interactions.

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

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. 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. 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. 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. 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.

Predictive factors of clinically significant drug–drug interactions among regimens based on protease inhibitors, non-nucleoside reverse transcriptase inhibitors and raltegravir

Background and objectiveTo determine the prevalence and types of clinically significant drug–drug interactions (CSDI) in the drug regimens of HIV-infected patients receiving antiretroviral treatment. Material and methodsDesign: retrospective review of database. Centre: Hospital Universitario Severo Ochoa, Infectious Unit. Participants: one hundred and forty-two participants followed by one of the authors were selected from January 1985 to December 2014. Data collection: from their outpatient medical records we reviewed information from the last available visit of the participants, in relation to HIV infection, comorbidities, demographics and the drugs that they were receiving; both antiretroviral drugs and drugs not related to HIV infection. We defined CSDI from the information sheet and/or database on antiretroviral drug interactions of the University of Liverpool (http://www.hiv-druginteractions.org) and we developed a diagnostic tool to predict the possibility of CSDI. By multivariate logistic regression analysis and by estimating the diagnostic performance curve obtained, we identified a quick tool to predict the existence of drug interactions. ResultsOf 142 patients, 39 (29.11%) had some type of CSDI and in 11.2% 2 or more interactions were detected. In only one patient the combination of drugs was contraindicated (this patient was receiving darunavir/r and quetiapine). In multivariate analyses, predictors of CSDI were regimen type (PI or NNRTI) and the use of 3 or more non-antiretroviral drugs (AUC 0.886, 95% CI 0.828–0.944; P=.0001). The risk was 18.55 times in those receiving NNRTI and 27.95 times in those receiving IP compared to those taking raltegravir. ConclusionsDrug interactions, including those defined as clinically significant, are common in HIV-infected patients treated with antiretroviral drugs, and the risk is greater in IP-based regimens. Raltegravir-based prescribing, especially in patients who receive at least 3 non-HIV drugs could avoid interactions.

Factores predictivos de las interacciones farmacológicas clínicamente significativas en los pacientes tratados con regímenes basados en inhibidores de proteasa, inhibidores de transcriptasa inversa no nucleósidos y raltegravir

Background and objectiveTo determine the prevalence and types of clinically significant drug-drug interactions (CSDI) in the drug regimens of HIV-infected patients receiving antiretroviral treatment. Material and methodsDesign: retrospective review of database. Centre: Hospital Universitario Severo Ochoa, Infectious Unit. Participants: one hundred and forty-two participants followed by one of the authors were selected from January 1985 to December 2014. Data collection: from their outpatient medical records we reviewed information from the last available visit of the participants, in relation to HIV infection, comorbidities, demographics and the drugs that they were receiving; both antiretroviral drugs and drugs not related to HIV infection. We defined CSDI from the information sheet and/or database on antiretroviral drug interactions of the University of Liverpool (http://www.hiv-druginteractions.org) and we developed a diagnostic tool to predict the possibility of CSDI. By multivariate logistic regression analysis and by estimating the diagnostic performance curve obtained, we identified a quick tool to predict the existence of drug interactions. ResultsOf 142 patients, 39 (29.11%) had some type of CSDI and in 11.2% 2 or more interactions were detected. In only one patient the combination of drugs was contraindicated (this patient was receiving darunavir/r and quetiapine). In multivariate analyses, predictors of CSDI were regimen type (PI or NNRTI) and the use of 3 or more non-antiretroviral drugs (AUC 0.886, 95% CI 0.828 to 0.944; P=.0001). The risk was 18.55 times in those receiving NNRTI and 27,95 times in those receiving IP compared to those taking raltegravir. ConclusionsDrug interactions, including those defined as clinically significant, are common in HIV-infected patients treated with antiretroviral drugs, and the risk is greater in IP-based regimens. Raltegravir-based prescribing, especially in patients who receive at least 3 non-HIV drugs could avoid interactions.

A Review of the Toxicity of HIV Medications II: Interactions with Drugs and Complementary and Alternative Medicine Products.

For many patients today, HIV has become a chronic disease. For those patients who have access to and adhere to lifelong antiretroviral (ARV) therapy, the potential for drug-drug interactions has become a real and life-threatening concern. It is known that most ARV drug interactions occur through the cytochrome P450 (CYP) pathway. Medications for comorbid medical conditions, holistic supplements, and illicit drugs can be affected by CYP inhibitors and inducers and have the potential to cause harm and toxicity. Protease inhibitors (PIs) tend to inhibit CYP3A4, while most non-nucleoside reverse transcriptase inhibitors (NNRTIs) tend to induce the enzyme. As such, failure to adjust the dose of co-administered medications, such as statins and steroids, may lead to serious complications including rhabdomyolysis and hypercortisolism, respectively. Similarly, gastric acid blockers can decrease several ARV absorption, and warfarin doses may need to be adjusted to maintain therapeutic concentrations. Illicit drugs such as methylenedioxymethamphetamine (MDMA, "ecstasy") in combination with PIs lead to increased toxicity, while the concomitant administration of sedative drugs such as midazolam and alprazolam in patients taking PIs can result in prolonged sedation, delayed recovery, and increased length of stay. Even supplements like St. John's Wort can alter PI concentrations. In theory, any drug that is metabolized by CYP has potential for a pharmacokinetic drug-drug interaction with all PIs, cobicistat, and most NNRTIs. When adding a new medication to an ARV regimen, use of a drug-drug interaction software and/or consultation with a clinical pharmacist/pharmacologist or HIV specialist is recommended.

Interactions of antiretroviral drugs with the SLC22A1 (OCT1) drug transporter.

The SLC22A1 influx transporter is expressed on the basolateral membrane of hepatocytes and is involved in the excretion of numerous cations. Inhibition of SLC22A1 by several antiretrovirals, such as the protease inhibitor darunavir, has not previously been determined. In order to better understand and predict drug-SLC22A1 interactions, a range of antiretrovirals were screened for SLC22A1-associated inhibition and transport. Stable SLC22A1-expressing KCL22 cells were produced previously by nucleofection. Control KCL22 cells were transfected with the empty vector pcDNA3.1. Accumulation of tetraethylammonium (5.5 μM, 30 min) was determined in SLC22A1-expressing and mock-transfected cells with and without 50 μM of SLC22A1 inhibitor prazosin, or 50 μM of each antiretroviral drug. SLC22A1 IC50 values for efavirenz, darunavir, and prazosin were determined. Cellular accumulation of efavirenz and darunavir was also assessed in SLC22A1-expressing KCL22 cells and reversibility of this accumulation was assessed using prazosin. Tetraethylammonium accumulation was higher in SLC22A1-expressing cells compared to mock-transfected cells (10.6 ± 0.8 μM vs. 0.3 ± 0.004 μM, p = 0.009) and was significantly reduced in SLC22A1-expressing cells when co-incubated with all antiretrovirals tested except atazanavir, lamivudine, tenofovir, zidovudine, and raltegravir. Particularly noticeable was the predominance of SLC22A1 inhibitors in the protease inhibitor and non-nucleoside reverse transcriptase inhibitor classes. Absolute SLC22A1 IC50 values for efavirenz, darunavir, and prazosin were 21.8, 46.2, and 2.8 μM, respectively. Efavirenz accumulation was higher in SLC22A1-expressing cells compared to mock-transfected cells (17% higher, p = 0.009) which was reversed using prazosin, whereas no difference was observed for darunavir (p = 0.86). These data inform the mechanistic basis for disposition, drug-drug interactions and pharmacogenetic candidate gene selection for antiretroviral drugs.

Efficacy and pharmacokinetics of the combination of etravirine plus raltegravir as novel dual antiretroviral maintenance regimen in HIV-infected patients

Novel combination antiretroviral regimens may be needed for selected HIV-infected patients with toxicity or resistance. We evaluated prospectively 25 virologically suppressed patients, largely pretreated (15.6years on therapy) with antiretroviral drug toxicity (n=19) or interactions (n=9, mainly with chemotherapy against non-Hodgkin lymphoma or anti-HCV therapy), who switched to a dual therapy with etravirine (ETR) plus raltegravir (RAL). Patients were required not to have prior virological failure or resistance to both drugs. After a median follow up of 722days (473–1088: 53.3 patients-year), there were no cases of transient virological replication or failure. Only 1 patient left therapy at day 10 due to a grade 2 rash, and therefore efficacy by intent-to-treat analysis was 96% at 48weeks. There were no cases of liver toxicity grade 3–4, and total cholesterol (TC) and triglycerides (TG) levels decrease significantly after initiation (TC, −17mg/dl; p=0.01; TG, −42mg/dl; p=0.01), as well as the TC/High density lipoprotein-cholesterol ratio (from 4.35 to 4.28). Geometric mean plasma trough level of RAL was 166ng/ml (IQR, 40–249), well above the inhibitory concentration 90 (IC90). In conclusion, a novel dual therapy with ETR plus RAL is effective and well tolerated, and it could be an option to maintain durable viral suppression in hard-to-treat HIV-infected patients.

Incidence of Antiretroviral Drug Interactions During Hospital Course: The Role of a Pharmacist-Led Antiretroviral Stewardship Program.

Background: Human immunodeficiency virus (HIV) providers are treating more comorbid conditions with additional pharmacologic agents, resulting in patients with HIV being disproportionately at risk for clinically significant drug-drug interactions (CSDDIs). There is a potential to overlook these interactions and ultimately place patients at risk for drug toxicity, resistance, and virologic failure. Objective: To assess the burden of CSDDIs among patients receiving antiretroviral therapy (ART) within 24 hours of admission and to evaluate the effect of a clinical pharmacist operating through an antiretroviral stewardship (ARVSP) program in identifying and correcting potential drug interactions. Methods: Adult HIV-positive patients receiving ART who were admitted to The Brooklyn Hospital Center from November 2010 through January 2012 were included in the analysis. Drug interactions were categorized according to time frame (ie, within 24 hours of admission vs after 24 hours of admission) and type (ie, contraindicated combinations, dosage modifications, and frequency alterations). The Liverpool HIV drug reference, Micromedex drug database, and the Department of Health and Human Services Guidelines were used as comprehensive tools for identification of antiretroviral drug errors. Results: Eighty-four CSDDIs were identified from 252 admissions among 158 patients receiving ART during the study period. Of the identified CSDDIs, 61 (73%) occurred within 24 hours of admission and 23 (27%) later in the hospital course. Forty-eight drug interactions (57%) represented contraindicated drug combinations. Protease inhibitor-based regimens were associated with the highest percentage of CSDDIs (98%). Of all CSDDIs, the most common interacting drug class was acid-suppressive therapy (63%). Clinical pharmacists identified and intervened in 80% of the CSDDIs that occurred on patient admission with all interventions accepted. Conclusions: CSDDIs are common among patients receiving ART at the time of admission and throughout the hospital course. Interventions including medication review by clinical pharmacists are critical in the prevention of CSDDIs on admission.

New Antiretroviral Therapies and Potential Drug Interactions in HIVInfected Drug Abusers

Substance abuse remains a major obstacle in treating HIV-infected patients. The high prevalence of drug use is responsible for lack of adherence and severe drug interactions to antiretroviral therapy in HIV positive individuals. Over the past decade, newer therapies for HIV have been developed by targeting different stages of HIV life cycle. Of importance, targeting initial binding with receptor and genome integration by CCR5 antagonists and integrase inhibitors, respectively have been effective in reducing viral loads in clinical trials. However, most of these recently approved or investigational antiretroviral drugs are also metabolized by cytochrome P450 (CYP) enzymes. Thus, substance abuse mediated changes in level of CYP enzymes (induction or inhibition) may result in severe drug interactions, failure of therapy, rapid progression to AIDS, and increased mortality in HIV patients who are treated with regimens containing CCR5 antagonists and integrase inhibitors. In this review, we have discussed the pharmacokinetic data, efficacy, lack of adherence to these therapies in drug abusers, and CYP-mediated potential drug interactions for CCR5 antagonists and integrase inhibitors in HIV-infected drug abusers.

A review of pharmacological interactions between HIV or hepatitis C virus medications and opioid agonist therapy: implications and management for clinical practice

Global access to opioid agonist therapy and HIV/hepatitis C virus (HCV) treatment is expanding but when used concurrently, problematic pharmacokinetic and pharmacodynamic interactions may occur. Articles published from 1966 to 2012 in Medline were reviewed using the following keywords: HIV, AIDS, HIV therapy, HCV, HCV therapy, antiretroviral therapy, highly active antiretroviral therapy, drug interactions, methadone and buprenorphine. In addition, a review of abstracts from national and international meetings and conference proceedings was conducted; selected reports were reviewed as well. The metabolism of both opioid and antiretroviral therapies, description of their known interactions and clinical implications and management of these interactions were reviewed. Important pharmacokinetic and pharmacodynamic drug interactions affecting either methadone or HIV medications have been demonstrated within each class of antiretroviral agents. Drug interactions between methadone, buprenorphine and HIV medications are known and may have important clinical consequences. Clinicians must be alert to these interactions and have a basic knowledge regarding their management.

Polypharmacy and Risk of Antiretroviral Drug Interactions Among the Aging HIV-Infected Population

Among aging HIV-infected adults, polypharmacy and its consequences have not been well-described. To characterize the extent of polypharmacy and the risk of antiretroviral (ARV) drug interactions among persons of different ages. Cross-sectional analysis among patients within the HIV Outpatient Study (HOPS) cohort who were prescribed ARVs during 2006-2010. We used the University of Liverpool HIV drug interactions database to identify ARV/non-ARV interactions with potential for clinical significance. Of 3,810 patients analyzed (median age 46 years, 34 % ≥ 50 years old) at midpoint of observation, 1,494 (39 %) patients were prescribed ≥ 5 non-ARV medications: 706 (54 %) of 1,312 patients ≥ 50 years old compared with 788 (32 %) of 2,498 patients < 50 years. During the five-year period, the number of patients who were prescribed at least one ARV/non-ARV combination that was contraindicated or had moderate or high evidence of interaction was 267 (7 %) and 1,267 (33 %), respectively. Variables independently associated with having been prescribed a contraindicated ARV/non-ARV combination included older age (adjusted odds ratio [aOR] per 10 years of age 1.17, 95 % CI 1.01-1.35), anxiety (aOR 1.78, 95 % CI 1.32-2.40), dyslipidemia (aOR 1.96, 95 % CI 1.28-2.99), higher daily non-ARV medication burden (aOR 1.13, 95 % CI 1.10-1.17), and having been prescribed a protease inhibitor (aOR 2.10, 95 % CI 1.59-2.76). Compared with patients < 50 years, older patients were more likely to have been prescribed an ARV/non-ARV combination that was contraindicated (unadjusted OR 1.44, 95 % CI 1.14-1.82), or had moderate or high evidence of interaction (unadjusted OR 1.29, 95 % CI 1.15-1.44). A substantial percentage of patients were prescribed at least one ARV/non-ARV combination that was contraindicated or had potential for a clinically significant interaction. As HIV-infected patients age and experience multiple comorbidities, systematic reviews of current medications by providers may reduce risk of such exposures.