Pharmacokinetic drug interactions between drugs of abuse and antiretroviral medications: implications and management for clinical practice

HIV and Substance Use Disorders

Over 1.2 million Americans aged 13 years and older have been diagnosed with human immunodeficiency virus (HIV). While HIV incidence has been declining since 2017, the risk of HIV acquisition and transmission persists among persons who use drugs via injection drug use and unprotected sexual intercourse associated with substance use. Untreated substance use disorder (SUD) is associated with poor adherence to HIV antiretroviral therapy, poor HIV outcomes, and increased risk for HIV acquisition. Herein, we describe the intertwined syndemic of HIV and SUD, as well as treatment strategies and evidence-based public health efforts to engage and retain persons who use drugs into care.

Alcohol Interaction with Cocaine, Methamphetamine, Opioids, Nicotine, Cannabis, and γ-Hydroxybutyric Acid

Millions of people around the world drink alcoholic beverages to cope with the stress of modern lifestyle. Although moderate alcohol drinking may have some relaxing and euphoric effects, uncontrolled drinking exacerbates the problems associated with alcohol abuse that are exploding in quantity and intensity in the United States and around the world. Recently, mixing of alcohol with other drugs of abuse (such as opioids, cocaine, methamphetamine, nicotine, cannabis, and γ-hydroxybutyric acid) and medications has become an emerging trend, exacerbating the public health concerns. Mixing of alcohol with other drugs may additively or synergistically augment the seriousness of the adverse effects such as the withdrawal symptoms, cardiovascular disorders, liver damage, reproductive abnormalities, and behavioral abnormalities. Despite the seriousness of the situation, possible mechanisms underlying the interactions is not yet understood. This has been one of the key hindrances in developing effective treatments. Therefore, the aim of this article is to review the consequences of alcohol's interaction with other drugs and decipher the underlying mechanisms.

Variation in antiretroviral treatment coverage and virological suppression among three HIV key populations

OBJECTIVES

We assessed differences in antiretroviral treatment (ART) coverage and virological suppression across three HIV key populations, as defined by self-reported HIV transmission category: sex between men, injection drug use (IDU) and heterosexual transmission.

DESIGN

A multinational cohort study.

METHODS

Within the EuroSIDA study, we assessed region-specific percentages of ART-coverage among those in care and virological suppression (<500 copies/ml) among those on ART, and analysed differences between transmission categories using logistic regression.

RESULTS

Among 12 872 participants followed from 1 July 2014 to 30 June 2016, the percentages of ART-coverage and virological suppression varied between transmission categories, depending on geographical region (global P for interaction: P = 0.0148 for ART-coverage, P = 0.0006 for virological suppression). In Western [adjusted odds ratio (aOR) 1.41 (95% confidence interval 1.14-1.75)] and Northern Europe [aOR 1.68 (95% confidence interval 1.25-2.26)], heterosexuals were more likely to receive ART than MSM, while in Eastern Europe, there was some evidence that infection through IDU [aOR 0.60 (95% confidence interval 0.31-1.14)] or heterosexual contact [aOR 0.58 (95% confidence interval 0.30-1.10)] was associated with lower odds of receiving ART. In terms of virological suppression, people infected through IDU or heterosexual contact in East Central and Eastern Europe were around half as likely as MSM to have a suppressed viral load on ART, while we observed no differences in virological suppression across transmission categories in Western and Northern Europe.

CONCLUSION

In our cohort, patterns of ART-coverage and virological suppression among key populations varied by geographical region, emphasizing the importance of tailoring HIV programmes to the local epidemic.

Prevalence and clinical impact of recreational drug consumption in people living with HIV on treatment: a cross-sectional study

OBJECTIVES

Drug interactions, poor adherence to medication and high-risk sexual behaviour may occur in individuals with HIV using recreational drugs. Thus, we aimed to assess the prevalence of recreational drugs use and to explore its clinical impact in HIV patients on treatment.

METHODS

Observational, cross sectional, study conducted in a 700 bed university hospital, Barcelona, Spain. A total of 208 adults living with HIV on treatment were included. A questionnaire was administered by clinical pharmacists, including evaluation of sociodemographic variables, past 12-month drug consumption, adherence to antiretrovirals (Simplified Medication Adherence Questionnaire) and high-risk sexual behaviour (condomless sex/multiple partners). Additional data were obtained from clinical records. Recreational drug-antiretroviral interactions were checked in reference databases. Prevalence was calculated for 5% precision and 95% CI. Crude and adjusted binary logistic regressions were performed to identify associations between recreational drug use and adherence problems, and between recreational drug use and high-risk sexual behaviour.

RESULTS

From the overall sample, 92 participants (44.2%) consumed recreational drugs over the past 1 year. Of these, 44 (48.8%) had used different types of recreational drugs in this period. We detected 11 recreational substances, including sildenafil and nitrites. The most consumed drugs were: cannabis (68.5%), cocaine (45.5%), nitrites (31.5%), sildenafil (28.3) and ecstasy (19.6%). Relevant interactions occurred in 46 (50%) of the individuals consuming drugs. Recreational drug consumption was found to be related to adherence problems with antiretrovirals (OR: 2.51 (95% CI 1.32 to 4.77) p=0.005) and high-risk sexual behaviour (OR: 2.81 (95% CI 1.47 to 5.39) p=0.002).

CONCLUSIONS

Recreational drugs are frequently used by HIV patients on treatment. Classical drugs and new substances consumed in sexual context are usual. Recreational drug consumption interferes with several clinical outcomes, including potentially relevant interactions between drugs and antiretrovirals, adherence problems and high-risk sexual behaviour. Thus, there is the urgent need of implementing patient-centred care involving recreational drug consumption.

Factors associated with optimal pharmacy refill adherence for antiretroviral medications and plasma HIV RNA non-detectability among HIV-positive crack cocaine users: a prospective cohort study

Background

Crack cocaine use is known to contribute to poor adherence to antiretroviral medications; however, little is known about facilitators of or barriers to effective HIV treatment use among HIV-infected crack cocaine users. We sought to identify correlates of optimal pharmacy refill adherence for antiretroviral medications and plasma HIV RNA viral load (pVL) suppression among this population.

Methods

Data from a prospective cohort of HIV-positive people who use illicit drugs in Vancouver, Canada, were linked to comprehensive HIV clinical monitoring and pharmacy dispensation records. We used multivariable generalized linear mixed-effects modelling to longitudinally identify factors associated with ≥95 % adherence to pharmacy refills for antiretroviral medications and pVL <50 copies/mL among crack cocaine users exposed to highly-active antiretroviral therapy (HAART).

Results

Among 438 HAART-exposed crack cocaine users between 2005 and 2013, 240 (54.8 %) had ≥95 % pharmacy refill adherence in the previous 6 months at baseline. In multivariable analyses, homelessness (adjusted odds ratio [AOR]: 0.58), ≥daily crack cocaine smoking (AOR: 0.64), and ≥ daily heroin use (AOR: 0.43) were independently associated with optimal pharmacy refill adherence (all p < 0.05). The results for pVL non-detectability were consistent with those of medication adherence, except that longer history of HAART (AOR: 1.06), receiving a single tablet-per-day regimen (AOR: 3.02) and participation in opioid substitution therapies was independently associated with pVL non-detectability (AOR: 1.55) (all p < 0.05).

Conclusions

Homelessness, and daily crack cocaine and/or heroin use were independently and negatively associated with optimal HAART-related outcomes. With the exception of opioid substitution therapies, no addiction treatment modalities assessed appeared to facilitate medication adherence or viral suppression. Evidence-based treatment options for crack cocaine use that also confer benefits to HAART need to be developed.

Burden and risk factors for gastrointestinal symptom distress in HIV patients in the modern antiretroviral era

In the modern antiretroviral (ARV) era, there is limited knowledge about the prevalence and risk factors for HIV patient-reported gastrointestinal (GI) symptoms (diarrhoea/soft stool, nausea/vomiting, bloating/painful abdomen, loss of appetite, and weight loss/wasting) and distress. We prospectively analysed data (2007-2014) on distressing GI symptoms from the Ontario HIV Treatment Network Cohort Study, which follows people attending HIV clinics. Using generalized estimating equations with a logit link, we estimated the associations of psychosocial, demographic, behavioural, and clinical factors with each GI symptoms compared to asymptomatic and non-bothersome symptoms. Among 1532 included participants, 80.4% were male, mean age was 45 years, and 64.6% reported being men who have sex with men. Most were Caucasian (56.3%), a median time since HIV diagnosis of 9.8 years (interquartile range (IQR): 4.1-16.9), and 83.1% were on ARV. More than two-thirds (68.7% (95% confidence intervals (CI): 63.1% to 69.2%)) reported one or more symptoms with a median of 1.2 (IQR: 0-1.7). The proportion remained stable over time since HIV diagnosis and ARV initiation. Risk factors varied for multivariable models. A strong association with Centre for Epidemiologic Studies Depression scale scores of ≥23 was found for all symptoms. Adjusted odds ratios (95% CI) were 1.72 (1.39-2.12), 2.95 (2.33-3.72), 2.20 (1.81-2.68), 4.97 (3.99-6.19), and 2.98 (2.52-3.82) for diarrhoea, nausea/vomiting, bloating, loss of appetite, and weight loss, respectively. With the exception of bloating, odds were significantly lower for those on ARV containing integrase inhibitors and greater for patients reporting current cannabis use. GI symptoms in the modern ARV era are highly prevalent and may arise as a common pathway of distress in response to psychosocial vulnerabilities, regardless of the stage of diagnosis. These findings support the need for integrated approaches to address psychological and physical distress in HIV disease.

Factors affecting the development of adverse drug reactions (Review article)

OBJECTIVES

To discuss the effect of certain factors on the occurrence of Adverse Drug Reactions (ADRs).

DATA SOURCES

A systematic review of the literature in the period between 1991 and 2012 was made based on PubMed, the Cochrane database of systematic reviews, EMBASE and IDIS. Key words used were: medication error, adverse drug reaction, iatrogenic disease factors, ambulatory care, primary health care, side effects and treatment hazards.

SUMMARY

Many factors play a crucial role in the occurrence of ADRs, some of these are patient related, drug related or socially related factors. Age for instance has a very critical impact on the occurrence of ADRs, both very young and very old patients are more vulnerable to these reactions than other age groups. Alcohol intake also has a crucial impact on ADRs. Other factors are gender, race, pregnancy, breast feeding, kidney problems, liver function, drug dose and frequency and many other factors. The effect of these factors on ADRs is well documented in the medical literature. Taking these factors into consideration during medical evaluation enables medical practitioners to choose the best drug regimen.

CONCLUSION

Many factors affect the occurrence of ADRs. Some of these factors can be changed like smoking or alcohol intake others cannot be changed like age, presence of other diseases or genetic factors. Understanding the different effects of these factors on ADRs enables healthcare professionals to choose the most appropriate medication for that particular patient. It also helps the healthcare professionals to give the best advice to patients. Pharmacogenomics is the most recent science which emphasizes the genetic predisposition of ADRs. This innovative science provides a new perspective in dealing with the decision making process of drug selection.

Design and synthesis of a bivalent ligand to explore the putative heterodimerization of the mu opioid receptor and the chemokine receptor CCR5

The bivalent ligand approach has been utilized not only to study the underlying mechanism of G protein-coupled receptors dimerization and/or oligomerization, but also to enhance ligand affinity and/or selectivity for potential treatment of a variety of diseases by targeting this process. Substance abuse and addiction have made both the prevention and the treatment of human immunodeficiency virus (HIV) infection more difficult to tackle. Morphine, a mu opioid receptor (MOR) agonist, can accelerate HIV infection through up-regulating the expression of the chemokine receptor CCR5, a well-known co-receptor for HIV invasion to the host cells and this has been extensively studied. Meanwhile, two research groups have described the putative MOR-CCR5 heterodimers in their independent studies. The purpose of this paper is to report the design and synthesis of a bivalent ligand to explore the biological and pharmacological process of the putative MOR-CCR5 dimerization phenomenon. The developed bivalent ligand thus contains two distinct pharmacophores linked through a spacer; ideally one of which will interact with the MOR and the other with the CCR5. Naltrexone and Maraviroc were selected as the pharmacophores to generate such a bivalent probe. The overall reaction route to prepare this bivalent ligand was convergent and efficient, and involved sixteen steps with moderate to good yields. The preliminary biological characterization showed that the bivalent compound 1 retained the pharmacological characteristics of both pharmacophores towards the MOR and the CCR5 respectively with relatively lower binding affinity, which tentatively validated our original molecular design.

Infectious disease comorbidities adversely affecting substance users with HIV: hepatitis C and tuberculosis

The linkage between drug use, particularly injection drug use, and HIV/AIDS, hepatitis C (HCV), and tuberculosis (TB) has been recognized since the beginning of the HIV pandemic. These comorbid conditions affect drug users worldwide and act synergistically, with resultant adverse biologic, epidemiologic, and clinical consequences. Prevention, care, and treatment of TB and HCV can be successful, and both diseases can be cured. Special clinical challenges among drug users, however, can result in increased morbidity, mortality, and decreased therapeutic success. Among these are limited disease screening, inadequate and insensitive diagnostics, difficult treatment regimens with varying toxicities, and complicated pharmacokinetic and pharmacodynamic drug interactions. These may result in delayed diagnosis, deferred treatment initiation, and low completion rates, with the potential for generation and transmission of drug resistant organisms. Strategies to address these challenges include outreach programs to engage substance abusers in nonmedical settings, such as prisons and the streets, active screening programs for HIV, HCV, and TB, increased and broadened clinician expertise, knowledge and avoidance of drug interactions, attention to infection control, use of isoniazid preventive therapy, and creative strategies to insure medication adherence. All of these require structural changes directed at comprehensive prevention and treatment programs and increased collaboration and integration of needed services for substance abusers.

Patterns of drug use and abuse among aging adults with and without HIV: a latent class analysis of a US Veteran cohort

This study characterized the extent and patterns of self-reported drug use among aging adults with and without HIV, assessed differences in patterns by HIV status, and examined pattern correlates. Data derived from 6351 HIV-infected and uninfected adults enrolled in an eight-site matched cohort, the Veterans Aging Cohort Study (VACS). Using clinical variables from electronic medical records and socio-demographics, drug use consequences, and frequency of drug use from baseline surveys, we performed latent class analyses (LCA) stratified by HIV status and adjusted for clinical and socio-demographic covariates. Participants were, on average, age 50 (range 22-86), primarily male (95%) and African-American (64%). Five distinct patterns emerged: non-users, past primarily marijuana users, past multidrug users, current high consequence multidrug users, and current low consequence primarily marijuana users. HIV status strongly influenced class membership. Non-users were most prevalent among HIV uninfected (36.4%) and current high consequence multidrug users (25.5%) were most prevalent among HIV-infected. While problems of obesity marked those not currently using drugs, current users experienced higher prevalences of medical or mental health disorders. Multimorbidity was highest among past and current multidrug users. HIV-infected participants were more likely than HIV-uninfected participants to be current low consequence primarily marijuana users. In this sample, active drug use and abuse were common. HIV-infected and uninfected Veterans differed on extent and patterns of drug use and on important characteristics within identified classes. Findings have the potential to inform screening and intervention efforts in aging drug users with and without HIV.

Medication-assisted treatment and HIV/AIDS: aspects in treating HIV-infected drug users

Drug use and HIV/AIDS remain serious public health issues in the US. The intersection of the twin epidemics of HIV and drug/alcohol use, results in difficult medical management issues for the healthcare providers who work in the HIV prevention and treatment fields. Access to care and treatment, medication adherence to multiple therapeutic regimens and concomitant drug-drug interactions of prescribed treatments are difficult barriers for drug users to overcome without directed interventions. Injection drug users are frequently disenfranchised from medical care and suffer stigma and discrimination creating additional barriers to care and treatment for their substance use disorders as well as HIV infection. Controlling the transmission of HIV will require access to care and treatment of individuals who abuse illicit drugs and alcohol. Improving health outcomes (e.g. access to and adherence to antiretroviral therapy) among HIV-infected substance users will also require access to evidenced-based pharmacological therapies for the treatment of drug abuse and dependence. The current review presents an overview of issues regarding the use of medication-assisted treatments for substance abuse and dependence among HIV-infected individuals, providing medical management paradigms for their care and treatment.

Drug abuse and hepatitis C infection as comorbid features of HIV associated neurocognitive disorder: neurocognitive and neuroimaging features

Substance abuse and co-infection with hepatitis C (HCV) are two highly relevant determinants of neurocognitive and neuroimaging abnormalities associated with HIV. Substance abuse and HCV are common in the HIV population and there is increasing evidence that the CNS is directly compromised by these comorbid conditions via additive or synergistic processes. In this article we review the current literature regarding mechanisms of neuronal injury as well as the neuropsychological and neuroimaging signatures associated with substance abuse and HCV status among HIV patients. We discuss specific methodological challenges and threats to validity associated with studies of HIV and comorbid substance use disorders or HCV and review potential strategies for minimizing their confounding effects. Efforts to understand the interactions between HIV, substance abuse and HCV co-infection will lead to more complete models of neuropathogenesis of HIV and a greater understanding of the variability in neuropsychological expression of HIV Associated Neurocognitive Disorder.