Efficacy of dolutegravir + lamivudine q.d. with food in people with TB/HIV using a rifampicin-based regimen: A retrospective observational case series

OBJECTIVES

Dolutegravir + lamivudine (DTG + 3TC) is a first-line regimen for people with HIV. However, there are still concerns about its efficacy in people with tuberculosis (TB)/HIV due to the lack of available evidence and drug-drug interaction with rifampicin.

METHODS

A single-centre retrospective observational case series was conducted in Guangxi Zhuang Autonomous Region, China. We included all people with TB/HIV on combined use of once-daily (q.d.) dosing DTG + 3TC and rifampicin (RIF)-containing anti-TB regimens between 2020 and 2022. HIV-RNA, CD4 cell counts were collected and analysed.

RESULTS

In all, 21 people with HIV (PWH) were included in this study. All the PWH were treatment-naïve and told to take DTG + 3TC q.d. with food. The median age was 53 years, and 71.43% were male. A total of 71.43% PWH had baseline viral load (VL) > 100 000 copies/mL, and 33.33% had baseline VL greater than 500 000 copies/mL. Only one PWH had CD4 cell count greater than 200 cells/μL, and the median CD4 count was 20 cells/μL. A total of 16 PWH started DTG + 3TC after initiation of the RIF-based anti-TB regimen, and the other five PWH initiated DTG + 3TC before the treatment of TB. All the PWH had at least 24 weeks of follow-up visits and all of the TB treatments were successful. A total of 20 PWH (95.24%) achieved viral suppression (VL <50 copies/mL). All detected viral loads between weeks 24 and 48 were less than 200 copies/mL. Among the PWH who started DTG + 3TC after the initiation of RIF-based anti-TB regimen, all achieved viral suppression by week 24 except the non-suppressed PWH. CD4 counts were greatly improved after antiretroviral treatment: the median CD4 counts were raised from 20 to 171 cells/μL at week 48. No serious adverse events were reported.

CONCLUSIONS

This case series preliminarily validates the efficacy of DTG + 3TC q.d. with food when combined with RIF-based anti-TB regimens in people with TB/HIV.

Pharmacokinetics of Efavirenz 600mg in Combination with Rifampicin in Chinese HIV/TB Co-Infection Patients

Background

Rifampicin is a known inducer of the cytochrome P450 (CYP2B6) enzyme, which can lead to a decrease in the concentration of efavirenz. Therefore, we conducted a study to evaluate the effect of daily rifampicin intake on efavirenz 600mg pharmacokinetics and HIV-1 virological suppression.

Methods

Patients receiving antiretroviral therapy containing efavirenz (600mg daily), and we collected efavirenz concentration at four visit points: ART day 14 (PK1), ART day 42 (PK2), ART day 140 (PK3), and ART day 336 (PK4), and performed pharmacokinetics analysis.

Results

From February 2017 to November 2020, 29 HIV/TB co-infection patients were included. Ninety percent of patients had a concentration of ≥1000ng/mL of efavirenz during the study. All patients had efavirenz C_max ≥1000ng/mL, 86% patients showed good virology response.

Conclusion

Our study shows that the use of rifampicin in HIV/TB co-infection patients does not affect efavirenz drug concentrations, that virological suppression is good and that no efavirenz dose adjustment is required.

Extensive Summary of the Important Roles of Indole Propionic Acid, a Gut Microbial Metabolite in Host Health and Disease

Increasing evidence suggests that metabolites produced by the gut microbiota play a crucial role in host-microbe interactions. Dietary tryptophan ingested by the host enters the gut, where indole-like metabolites such as indole propionic acid (IPA) are produced under deamination by commensal bacteria. Here, we summarize the IPA-producing bacteria, dietary patterns on IPA content, and functional roles of IPA in various diseases. IPA can not only stimulate the expression of tight junction (TJ) proteins to enhance gut barrier function and inhibit the penetration of toxic factors, but also modulate the immune system to exert anti-inflammatory and antioxidant effects to synergistically regulate body physiology. Moreover, IPA can act on target organs through blood circulation to form the gut-organ axis, which helps maintain systemic homeostasis. IPA shows great potential for the diagnosis and treatment of various clinical diseases, such as NAFLD, Alzheimer's disease, and breast cancer. However, the therapeutic effect of IPA depends on dose, target organ, or time. In future studies, further work should be performed to explore the effects and mechanisms of IPA on host health and disease to further improve the existing treatment program.

Impact of Dolutegravir-Based Antiretroviral Therapy on Piperaquine Exposure following Dihydroartemisinin-Piperaquine Intermittent Preventive Treatment of Malaria in Pregnant Women Living with HIV

Dihydroartemisinin-piperaquine, an artemisinin-based combination therapy, has been identified as a promising agent for intermittent preventive treatment of malaria in pregnancy. However, in pregnant women living with HIV (PLWH), efavirenz-based antiretroviral therapy (ART) significantly reduces the plasma exposure of piperaquine. In an open-label, nonrandomized, fixed-sequence, pharmacokinetic study, we compared piperaquine plasma concentrations in 13 pregnant women during a 3-day treatment course of dihydroartemisinin-piperaquine when coadministered with efavirenz-based versus dolutegravir-based ART in the second or third trimester of pregnancy. Piperaquine concentrations were measured over a 28-day period, while on efavirenz-based ART and after switching to dolutegravir-based ART. Noncompartmental analysis was performed, and geometric mean ratios (GMRs) and 90% confidence intervals (CIs) were generated to compare piperaquine pharmacokinetic parameters between these two treatment periods. Compared with efavirenz-based ART, coadministration of dihydroartemisinin-piperaquine and dolutegravir-based ART resulted in a 57% higher overall piperaquine exposure (area under the concentration-time curve from 0 to 672 h [AUC_{0-672 h}]) (GMR, 1.57; 90% CI, 1.28 to 1.93). Piperaquine's day 7 concentrations were also 63% higher (GMR, 1.63; 90% CI, 1.29 to 2.11), while day 28 concentrations were nearly three times higher (GMR, 2.96; 90% CI, 2.25 to 4.07). However, the maximum piperaquine concentration (C_max) remained similar (GMR, 1.09; 90% CI, 0.79 to 1.49). Dihydroartemisinin-piperaquine was well tolerated, with no medication-related serious adverse events observed in this small study. Compared with efavirenz-based ART, a known inducer of piperaquine metabolism, dolutegravir-based ART resulted in increased overall piperaquine exposure with pharmacokinetic parameter values that were similar to those published previously for pregnant and nonpregnant women. Our findings suggest that the efficacy of dihydroartemisinin-piperaquine will be retained in pregnant women on dolutegravir. (The study was registered on PACTR.samrc.ac.za [PACTR201910580840196].).

Hidradenitis Suppurativa in Patients with HIV: A Scoping Review

Hidradenitis suppurativa (HS) is a chronic, debilitating skin disease of the apocrine glands. Bibliographic search revealed few studies concerning the association between HS and human immunodeficiency virus (HIV). To assess this link, we performed a systematic review of the current knowledge through a careful analysis of the relevant and authoritative medical literature in the field. Results showed that people with HIV are particularly susceptible to developing HS with the characteristic involvement of atypical sites, such as face or thighs, due to HIV-related immunosuppression. Based on the pathogenesis of both conditions and according to our review, we suggest that HIV screening should be routinely performed in suspected cases while monitoring and integrated approach in management are mandatory in the management of HIV-positive patients with HS.

Effect of dihydroartemisinin/piperaquine for malaria intermittent preventive treatment on dolutegravir exposure in pregnant women living with HIV

BACKGROUND

In sub-Saharan Africa, the burdens of malaria and HIV infections overlap. In settings with moderate-to-high malaria transmission intensity, pregnant women living with HIV (PLWH) require both ART and malaria intermittent preventive treatment (IPTp). Dihydroartemisinin/piperaquine has been identified as a promising alternative to sulfadoxine/pyrimethamine for IPTp. However, another antimalarial drug, artesunate/amodiaquine, similar to dihydroartemisinin/piperaquine, was previously shown to reduce dolutegravir exposure in non-pregnant adults.

OBJECTIVES

To investigate the effect of dihydroartemisinin/piperaquine on dolutegravir plasma exposure in pregnant women on dolutegravir-based ART.

METHODS

We conducted an open-label, non-randomized, fixed-sequence, pharmacokinetic study in PLWH in Malawi. Dolutegravir concentrations were measured over a 24 h period, before and after the recommended 3 day treatment dose of dihydroartemisinin/piperaquine in 12 pregnant women in their second or third trimester. Non-compartmental analysis was performed, and geometric mean ratios (GMRs) and 90% CIs were generated to compare dolutegravir pharmacokinetic parameters between the two treatment periods.

RESULTS

Co-administration of dihydroartemisinin/piperaquine and dolutegravir increased dolutegravir's overall exposure (AUC0-24) and Cmax by 30% (GMR 1.30; 90% CI 1.11-1.52) and 31% (GMR 1.31; 90% CI 1.13-1.51), respectively. The dolutegravir trough (C24) concentration increased by 42% (GMR 1.42; 90% CI 1.09-1.85). The combined treatments were well tolerated with no serious adverse events observed.

CONCLUSIONS

Dihydroartemisinin/piperaquine may be administered with dolutegravir-based ART in pregnant women as the modest increase in dolutegravir exposure, similar to pharmacokinetic parameter values published previously, ensures its efficacy without any clinically significant adverse events observed in this small study.

Dolutegravir-based Antiretroviral Therapy for Patients Coinfected With Tuberculosis and Human Immunodeficiency Virus: A Multicenter, Noncomparative, Open-label, Randomized Trial

BACKGROUND

The concurrent treatment of tuberculosis and human immunodeficiency virus (HIV) is challenging, owing to drug interactions, overlapping toxicities, and immune reconstitution inflammatory syndrome (IRIS). The efficacy and safety of dolutegravir (DTG) were assessed in adults with HIV and drug-susceptible tuberculosis.

METHODS

International Study of Patients with HIV on Rifampicin ING is a noncomparative, active-control, randomized, open-label study in HIV-1-infected antiretroviral therapy-naive adults (CD4+ ≥50 cells/mm3). Participants on rifampicin-based tuberculosis treatment ≤8 weeks were randomized (3:2) to receive DTG (50 mg twice daily both during and 2 weeks after tuberculosis therapy, then 50 mg once daily) or efavirenz (EFV; 600 mg daily) with 2 nucleoside reverse transcriptase inhibitors for 52 weeks. The primary endpoint was the proportion of DTG-arm participants with plasma HIV-1-RNA <50 copies/mL (responders) by the Food and Drug Administration Snapshot algorithm (intent-to-treat exposed population) at Week 48. The study was not powered to compare arms.

RESULTS

For DTG (n = 69), the baseline HIV-1 RNA was >100 000 copies/mL in 64% of participants, with a median CD4+ count of 208 cells/mm3; for EFV (n = 44), 55% of participants had HIV-1 RNA >100 000 copies/mL, with a median CD4+ count of 202 cells/mm3. The Week 48 response rates were 75% (52/69, 95% confidence interval [CI] 65-86%) for DTG and 82% (36/44, 95% CI 70-93%) for EFV. The DTG nonresponses were driven by non-treatment related discontinuations (n = 10 lost to follow-up). There were no deaths or study drug switches. There were 2 discontinuations for toxicity (EFV). There were 3 protocol-defined virological failures (2 DTG, no acquired resistance; 1 EFV, emergent resistance to nucleoside reverse transcriptase inhibitors and nonnucleoside reverse transcriptase inhibitors). The tuberculosis treatment success rate was high. Tuberculosis-associated IRIS was uncommon (4/arm), with no discontinuations for IRIS.

CONCLUSIONS

Among adults with HIV receiving rifampicin-based tuberculosis treatment, twice-daily DTG was effective and well tolerated.

CLINICAL TRIALS REGISTRATION

NCT02178592.

Synergistic and antagonistic drug interactions in the treatment of systemic fungal infections

Invasive fungal infections cause 1.6 million deaths annually, primarily in immunocompromised individuals. Mortality rates are as high as 90% due to limited treatments. The azole class antifungal, fluconazole, is widely available and has multi-species activity but only inhibits growth instead of killing fungal cells, necessitating long treatments. To improve treatment, we used our novel high-throughput method, the overlap² method (O2M) to identify drugs that interact with fluconazole, either increasing or decreasing efficacy. We identified 40 molecules that act synergistically (amplify activity) and 19 molecules that act antagonistically (decrease efficacy) when combined with fluconazole. We found that critical frontline beta-lactam antibiotics antagonize fluconazole activity. A promising fluconazole-synergizing anticholinergic drug, dicyclomine, increases fungal cell permeability and inhibits nutrient intake when combined with fluconazole. In vivo, this combination doubled the time-to-endpoint of mice with Cryptococcus neoformans meningitis. Thus, our ability to rapidly identify synergistic and antagonistic drug interactions can potentially alter the patient outcomes.

Individuals with weakened immune systems – such as recipients of organ transplants – can fall prey to illnesses caused by fungi that are harmless to most people. These infections are difficult to manage because few treatments exist to fight fungi, and many have severe side effects. Antifungal drugs usually slow the growth of fungi cells rather than kill them, which means that patients must remain under treatment for a long time, or even for life.

One way to boost efficiency and combat resistant infections is to combine antifungal treatments with drugs that work in complementary ways: the drugs strengthen each other’s actions, and together they can potentially kill the fungus rather than slow its progression. However, not all drug combinations are helpful. In fact, certain drugs may interact in ways that make treatment less effective. This is particularly concerning because people with weakened immune systems often take many types of medications.

Here, Wambaugh et al. harnessed a new high-throughput system to screen how 2,000 drugs (many of which already approved to treat other conditions) affected the efficiency of a common antifungal called fluconazole. This highlighted 19 drugs that made fluconazole less effective, some being antibiotics routinely used to treat patients with weakened immune systems.

On the other hand, 40 drugs boosted the efficiency of fluconazole, including dicyclomine, a compound currently used to treat inflammatory bowel syndrome. In fact, pairing dicyclomine and fluconazole more than doubled the survival rate of mice with severe fungal infections. The combined treatment could target many species of harmful fungi, even those that had become resistant to fluconazole alone.

The results by Wambaugh et al. point towards better treatments for individuals with serious fungal infections. Drugs already in circulation for other conditions could be used to boost the efficiency of fluconazole, while antibiotics that do not decrease the efficiency of this medication should be selected to treat at-risk patients.

Pharmacokinetics of HIV therapies in pregnant patients: an update

INTRODUCTION

Mother-to-child transmission (MTCT) of HIV is thought to account for over 90% of new pediatric infections, and is associated with poor maternal and fetal outcomes. As such ensuring further reduction in MTCT is a priority in HIV treatment and prevention programs.

AREAS COVERED

This review aims to provide a comprehensive update on the pharmacokinetics of recently approved antiretroviral drugs and novel drug formulations and delivery systems. Alongside recent recommendations for dose adjustments, and an overview of the implications of co-infections on the pharmacokinetics of antiretrovirals relevant to pregnant HIV positive patients. Additionally, potential opportunities to progress pharmacokinetic research of new treatments in this population are highlighted.

EXPERT OPINION

In order to improve our understanding of how to provide safe and effective treatment to HIV positive pregnant women, further work is required to enable their inclusion in early stages of clinical trials. Incentives must be created for this research, in the form of additional investment by key stakeholders and regulatory agencies. Furthermore, as the incidence of MTCT is reduced globally there is a need to conduct long-term pharmacovigilance studies in uninfected children exposed to HIV and antiretrovirals in utero, in order to determine the safest and most effective antiretroviral therapies.

Demanding an end to tuberculosis: treatment of tuberculosis infection among persons living with and without HIV

PURPOSE OF REVIEW

More than two billion people are infected with Mycobacterium tuberculosis and few of them are ever offered therapy in spite of such treatment being associated with reduced rates of morbidity and mortality. This article reviews the current recommendations on the diagnosis and treatment of TB infection (or what is commonly referred to as 'prophylaxis' or 'preventive therapy' of latent TB) and discusses barriers to implementation that have led to low demand for this life-saving therapeutic intervention.

RECENT FINDINGS

Treatment of infection for both TB and drug-resistant TB is well tolerated and effective, and several new, shorter regimens - including rfiapenitine-based regimens of 1 month and 12 weeks duration - have been shown to be effective. Not all persons infected with TB go on to develop disease and the risk is the highest in the first 2 years after infection. Given this, additional work is needed to better identify those at the highest risk of developing active TB.

SUMMARY

Practitioners should offer newer, shorter regimens to persons who are infected with TB and at high risk of developing disease, including people living with HIV and household contacts of people living with TB who are age 5 years and under. This includes individuals who have been exposed to drug-resistant forms of disease. Socioeconomic risk factors may play a key role in the development of TB disease and should also be addressed.

Drug-Resistant Tuberculosis and HIV Infection: Current Perspectives

Drug-resistant tuberculosis (DR-TB), including multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB), is considered a potential obstacle for elimination of TB globally. HIV coinfection with M/XDR-TB further complicates the scenario, and is a potential threat with challenging management. Reports have shown poor outcomes and alarmingly high mortality rates among people living with HIV (PLHIV) coinfected with M/XDR-TB. This coinfection is also responsible for all forms of M/XDR-TB epidemics or outbreaks. Better outcomes with reductions in mortality have been reported with concomitant treatment containing antiretroviral drugs for the HIV component and antitubercular drugs for the DR-TB component. Early and rapid diagnosis with genotypic tests, prompt treatment with appropriate regimens based on drug-susceptibility testing, preference for shorter regimens fortified with newer drugs, a patient-centric approach, and strong infection-control measures are all essential components in the management of M/XDR-TB in people living with HIV.

Prevalence and management of drug-drug interactions with antiretroviral treatment in 2069 people living with HIV in rural Tanzania: a prospective cohort study

OBJECTIVES

Widespread access to antiretroviral therapy (ART) has substantially increased life expectancy in sub-Saharan African countries. As a result, the rates of comorbidities and use of co-medications among people living with HIV are increasing, necessitating a sound understanding of drug-drug interactions (DDIs). We aimed to assess the prevalence and management of DDIs with ART in a rural Tanzanian setting.

METHODS

We included consenting HIV-positive adults initiating ART in the Kilombero and Ulanga Antiretroviral Cohort (KIULARCO) between January 2013 and December 2016. DDIs were classified using www.hiv-druginteractions.org as red (contra-indicated), amber (potential clinical relevance requiring dosage adjustment/monitoring), yellow (weak clinical significance unlikely to require further management) or green (no interaction). We assessed management of amber DDIs by evaluating monitoring of laboratory or clinical parameters, or changes in drug dosages.

RESULTS

Of 2069 participants, 1945 (94%) were prescribed at least one co-medication during a median follow-up of 1.8 years. Of these, 645 (33%) had at least one potentially clinically relevant DDI, with the highest grade being red in nine (< 1%) and amber in 636 (33%) participants. Of the 23 283 prescriptions, 19 (< 1%) and 1745 (7%) were classified as red and amber DDIs, respectively. Overall, 351 (2%) prescriptions were red DDIs or not appropriately managed amber DDIs.

CONCLUSIONS

Co-medication use was common in this rural sub-Saharan cohort. A third of participants had DDIs requiring further management. Of the 9% of participants with not appropriately managed DDIs, most were with cardiovascular and analgesic drugs. This highlights the importance of physicians' awareness of DDIs for their recognition and management.

Anti-HIV and Anti-Hepatitis C Virus Drugs Inhibit P-Glycoprotein Efflux Activity in Caco-2 Cells and Precision-Cut Rat and Human Intestinal Slices

P-glycoprotein (ABCB1), an ATP-binding-cassette efflux transporter, limits intestinal absorption of its substrates and is a common site of drug-drug interactions (DDIs). ABCB1 has been suggested to interact with many antivirals used to treat HIV and/or chronic hepatitis C virus (HCV) infections. Using bidirectional transport experiments in Caco-2 cells and a recently established ex vivo model of accumulation in precision-cut intestinal slices (PCIS) prepared from rat ileum or human jejunum, we evaluated the potential of anti-HIV and anti-HCV antivirals to inhibit intestinal ABCB1. Lopinavir, ritonavir, saquinavir, atazanavir, maraviroc, ledipasvir, and daclatasvir inhibited the efflux of a model ABCB1 substrate, rhodamine 123 (RHD123), in Caco-2 cells and rat-derived PCIS. Lopinavir, ritonavir, saquinavir, and atazanavir also significantly inhibited RHD123 efflux in human-derived PCIS, while possible interindividual variability was observed in the inhibition of intestinal ABCB1 by maraviroc, ledipasvir, and daclatasvir. Abacavir, zidovudine, tenofovir disoproxil fumarate, etravirine, and rilpivirine did not inhibit intestinal ABCB1. In conclusion, using recently established ex vivo methods for measuring drug accumulation in rat- and human-derived PCIS, we have demonstrated that some antivirals have a high potential for DDIs on intestinal ABCB1. Our data help clarify the molecular mechanisms responsible for reported increases in the bioavailability of ABCB1 substrates, including antivirals and drugs prescribed to treat comorbidity. These results could help guide the selection of combination pharmacotherapies and/or suitable dosing schemes for patients infected with HIV and/or HCV.

Reasons for Antiretroviral Treatment Change Among Adult HIVAIDS Patients at Nedjo General Hospital, Western Ethiopia

Background:

Frequent change of Antiretroviral Treatment (ART) regimen is a challenging problem especially in a resource-limited setting like Ethiopia where treatment options are limited. This study was aimed to identify reasons for ART regimen change among adult HIV patients at Nedjo General Hospital (NGH).

Methods:

An institutional-based retrospective cross-sectional study was conducted at NGH by reviewing patient information cards from 2006 to 2016.

Results:

From a total of 117 included patients, 50.4% were females and the median (IQR) age of the patients was 28 (24-47) years. Majority of patients, 63 (53.9%) started their treatment at world health organization (WHO) clinical stage III (53.9%) and CD4 count of between 200-350 cells/mm3 (44.54%). At the beginning of ART, 56 (47.9%) patients were on a fixed-dose combination of stavudine-lamivudine-nevirapine (D4T/3TC/NVP). The single-drug substitutions were D4T (n = 63), NVP (n = 34), AZT (n =5), EFV (n = 2), and TDF (n = 1). Majority of the patients, 35(29.9%) switched their initial ART regimen after 3 years of regimen commencement. The common reasons reported for initial regimen change was availability of new drug 46 (39.3%) followed by toxicity/side effects 34 (29.2%). From all toxicities, peripheral neuropathy (47.1%) was the most common toxicity followed by rash (20.6%). After regimen change, 47 (40.2%) were received AZT+3TC+NVP.

Conclusion:

Availability of new drug and toxicity were the common reasons for regimen modifications. There should be updated guidelines, sustainable supply of affordable ART drugs, and effective laboratory materials to increase treatment success and minimize the toxicity of the drugs.

Inclusion of key populations in clinical trials of new antituberculosis treatments: Current barriers and recommendations for pregnant and lactating women, children, and HIV-infected persons

Amita Gupta and colleagues discuss priorities in clinical research aimed at improving tuberculosis prevention and treatment in pregnant women, children, and people with HIV.

Pharmacokinetics and pharmacodynamics of cytochrome P450 inhibitors for HIV treatment

INTRODUCTION

Drugs used in HIV treatment; all protease inhibitors, some non-nucleoside reverse transcriptase inhibitors, and pharmacoenhancers ritonavir and cobicistat can inhibit cytochrome P450 (CYP) enzymes. CYP inhibition can cause clinically significant drug-drug interactions (DDI), leading to increased drug exposure and potential toxicity. Areas covered: A complete understanding of pharmacodynamics and CYP-mediated DDI is crucial to prevent adverse side effects and to achieve optimal efficacy. We summarized the pharmacodynamics of all the CYP inhibitors used for HIV treatment, followed by a discussion of drug interactions between these CYP inhibitors and other drugs, and a discussion on the effect of CYP polymorphisms. We also discussed the potential advancements in improving the pharmacodynamics of these CYP inhibitors by using nanotechnology strategy. Expert opinion: The drug-interactions in HIV patients receiving ARV drugs are complicated, especially when patients are on CYP inhibitors-based ART regimens. Therefore, evaluation of CYP-mediated drug interactions is necessary prior to prescribing ARV drugs to HIV subjects. To improve the treatment efficacy and minimize DDI, novel approaches such as nanotechnology may be the potential alternative approach. However, further studies with large cohort need to be conducted to provide strong evidence for the use of nano-formulated ARVs to effectively treat HIV patients.

Health Considerations for HIV-Infected International Travelers

PURPOSE OF THE REVIEW

International travel continues to steadily increase, including leisure travel, travel to one's country of origin to visit friends and relatives, travel for service work, and business travel. Travelers with HIV may have an increased risk for travel-associated infections. The pre-travel medical consultation is an important means of assessing one's risk for travel-related health issues. The aim of this review is to provide an update on key health considerations for the HIV-infected traveler.

RECENT FINDINGS

Like all travelers, the HIV-infected traveler should adhere to behavioral precautions, including safety measures with food and water consumption, safe sexual practices, and arthropod bite avoidance. HIV is a risk factor for venous thromboembolism and patients should be educated regarding this risk. Most pre-travel vaccines are safe and immunogenic in HIV-infected individuals, though live vaccines should be avoided in patients with low CD4 counts. Malaria chemoprophylaxis is strongly recommended in patients with HIV traveling to endemic areas and no significant interactions exist between the commonly used prophylactic anti-malarial agents and anti-retroviral therapy (ART). Travelers with HIV, particularly those who are not on ART or who have low CD4 cell counts, may have increased risk for tuberculosis, malaria, enteric infections, visceral leishmaniasis, American trypanosomiasis, and endemic mycoses such as histoplasmosis, talaromycosis, and coccidioidomycosis. The immune status of the HIV-infected traveler should be assessed prior to travel along with the duration, itinerary, and activities planned during travel in order to carefully consider individual risk for travel-related health issues.

The cost-effectiveness and budgetary impact of a dolutegravir-based regimen as first-line treatment of HIV infection in India

INTRODUCTION

Dolutegravir (DTG)-based antiretroviral therapy (ART) is recommended for first-line HIV treatment in the US and Europe. Efavirenz (EFV)-based regimens remain the standard of care (SOC) in India. We examined the clinical and economic impact of DTG-based first-line ART in the setting of India's recent guidelines change to treating all patients with HIV infection regardless of CD4 count.

METHODS

We used a microsimulation of HIV disease, the Cost-Effectiveness of Preventing AIDS Complications (CEPAC)-International model, to project outcomes in ART-naive patients under two strategies: (1) SOC: EFV/tenofovir disoproxil fumarate (TDF)/lamivudine (3TC); and (2) DTG: DTG + TDF/3TC. Regimen-specific inputs, including virologic suppression at 48 weeks (SOC: 82% vs. DTG: 90%) and annual costs ($98 vs. $102), were informed by clinical trial data and other sources and varied widely in sensitivity analysis. We compared incremental cost-effectiveness ratios (ICERs), measured in $/year of life saved (YLS), to India's per capita gross domestic product ($1600 in 2015). We compared the budget impact and HIV transmission effects of the two strategies for the estimated 444,000 and 916,000 patients likely to initiate ART in India over the next 2 and 5 years.

RESULTS

Compared to SOC, DTG improved 5-year survival from 76.7% to 83.0%, increased life expectancy from 22.0 to 24.8 years (14.0 to 15.5 years, discounted), averted 13,000 transmitted HIV infections over 5 years, increased discounted lifetime care costs from $3040 to $3240, and resulted in a lifetime ICER of $130/YLS, less than 10% of India's per capita GDP in 2015. DTG maintained an ICER below 50% of India's per capita GDP as long as the annual three-drug regimen cost was ≤$180/year. Over a 2- or 5-year horizon, total undiscounted outlays for HIV-related care were virtually the same for both strategies.

CONCLUSIONS

A generic DTG-based regimen is likely to be cost-effective and should be recommended for initial therapy of HIV infection in India.

Tropical Parasitic Infections in Individuals Infected with HIV

PURPOSE OF REVIEW

Neglected tropical diseases share both geographic and socio-behavioral epidemiological risk factors with HIV infection. In this literature review, we describe interactions between parasitic diseases and HIV infection, with a focus on the impact of parasitic infections on HIV infection risk and disease progression, and the impact of HIV infection on clinical characteristics of tropical parasitic infections. We limit our review to tropical parasitic infections of the greatest public health burden, and exclude discussion of classic HIV-associated opportunistic infections that have been well reviewed elsewhere.

RECENT FINDINGS

Tropical parasitic infections, HIV-infection, and treatment with antiretroviral therapy alter host immunity, which can impact susceptibility, transmissibility, diagnosis, and severity of both HIV and parasitic infections. These relationships have a broad range of consequences, from putatively increasing susceptibility to HIV acquisition, as in the case of schistosomiasis, to decreasing risk of protozoal infections through pharmacokinetic interactions between antiretroviral therapy and antiparasitic agents, as in the case of malaria. However, despite this intimate interplay in pathophysiology and a broad overlap in epidemiology, there is a general paucity of data on the interactions between HIV and tropical parasitic infections, particularly in the era of widespread antiretroviral therapy availability.

SUMMARY

Additional data are needed to motivate clinical recommendations for detection and management of parasitic infections in HIV-infected individuals, and to consider the implications of and potential opportunity granted by HIV treatment programs on parasitic disease control.

Effect of Rifampin on the Single-Dose Pharmacokinetics of Oral Cabotegravir in Healthy Subjects

Drug-drug interactions between antiretroviral medications and rifampin complicate the treatment of HIV and tuberculosis coinfection. This study evaluated the effect of rifampin on the pharmacokinetics of oral cabotegravir, an integrase strand transfer inhibitor being investigated for long-acting treatment and prevention of HIV-1 infection. This was a phase I, single-center, open-label, fixed-sequence crossover study in healthy adults. The objective was to evaluate the effect of steady-state rifampin on the single-dose plasma pharmacokinetics of cabotegravir. Subjects received a single oral dose of cabotegravir (30 mg) on day 1 followed by plasma sampling on days 1 to 8. Treatment with once-daily oral rifampin (600 mg) occurred on days 8 to 28. Subjects received a second dose of 30 mg cabotegravir on day 21 followed by pharmacokinetic sampling on days 21 to 28. Fifteen subjects were enrolled and completed the study. Rifampin decreased the cabotegravir area under the concentration-time curve from 0 h to infinity and the half-life by 59% and 57%, respectively, whereas oral clearance was increased 2.4-fold. The maximum concentration of cabotegravir in plasma was unaffected by coadministration with rifampin. All adverse events were mild in severity, with chromaturia attributed to rifampin observed in all subjects. Rifampin induction of cabotegravir metabolism resulted in increased cabotegravir oral clearance and significantly decreased cabotegravir exposures. Rifampin is expected to increase cabotegravir clearance following long-acting injectable administration. Concomitant administration of rifampin with oral and long-acting formulations of cabotegravir is not recommended currently without further study. (This study has been registered at ClinicalTrials.gov under registration no. NCT02411435.).

Addressing Antiretroviral Therapy-Associated Drug-Drug Interactions in Patients Requiring Treatment for Opportunistic Infections in Low-Income and Resource-Limited Settings

An increasing number of human immunodeficiency virus (HIV)-infected patients are achieving virologic suppression on antiretroviral therapy (ART) limiting the use of primary and secondary antimicrobial prophylaxis. However, in low-income and resource-limited settings, half of those infected with HIV are unaware of their diagnosis, and fewer than 50% of patients on ART achieve virologic suppression. Management of comorbidities and opportunistic infections among patients on ART may lead to inevitable drug-drug interactions (DDIs) and even toxicities. Elderly patients, individuals with multiple comorbidities, those receiving complex ART, and patients living in low-income settings experience higher rates of DDIs. Management of these cytochrome P450-mediated, nonmediated, and drug transport system DDIs is critical in HIV-infected patients, particularly those in resource-limited settings with few options for ART. This article critically analyzes and provides recommendations to manage significant DDIs and drug toxicities in HIV-infected patients receiving ART.

Antiretroviral Therapy With Efavirenz Accentuates Pregnancy-Associated Reduction of Dihydroartemisinin-Piperaquine Exposure During Malaria Chemoprevention

Dihydroartemisinin (DHA)-piperaquine is promising for malaria chemoprevention in pregnancy. We assessed the impacts of pregnancy and efavirenz-based antiretroviral therapy on exposure to DHA and piperaquine in pregnant Ugandan women. Intensive sampling was performed at 28 weeks gestation in 31 HIV-uninfected pregnant women, in 27 HIV-infected pregnant women receiving efavirenz, and in 30 HIV-uninfected nonpregnant women. DHA peak concentration and area under the concentration time curve (AUC0-8hr ) were 50% and 47% lower, respectively, and piperaquine AUC0-21d was 40% lower in pregnant women compared to nonpregnant women. DHA AUC0-8hr and piperaquine AUC0-21d were 27% and 38% lower, respectively, in pregnant women receiving efavirenz compared to HIV-uninfected pregnant women. Exposure to DHA and piperaquine were lower among pregnant women and particularly in women on efavirenz, suggesting a need for dose modifications. The study of modified dosing strategies for these populations is urgently needed.

Tuberculosis Associated with HIV Infection

Tuberculosis (TB) has recently surpassed HIV as the primary infectious disease killer worldwide, but the two diseases continue to display lethal synergy. The burden of TB is disproportionately borne by people living with HIV, particularly where HIV and poverty coexist. The impact of these diseases on one another is bidirectional, with HIV increasing risk of TB infection and disease progression and TB slowing CD4 recovery and increasing progression to AIDS and death among the HIV infected. Both antiretroviral therapy (ART) and latent TB infection (LTBI) treatment mitigate the impact of coinfection, and ART is now recommended for HIV-infected patients independent of CD4 count. LTBI screening should be performed for all HIV-positive people at the time of diagnosis, when their CD4 count rises above 200, and yearly if there is repeated exposure. Tuberculin skin tests (TSTs) may perform better with serial testing than interferon gamma release assays (IGRAs). Any patient with HIV and a TST induration of ≥5 mm should be evaluated for active TB disease and treated for LTBI if active disease is ruled out. Because HIV impairs multiple aspects of immune function, progressive HIV is associated with lower rates of cavitary pulmonary TB and higher rates of disseminated and extrapulmonary disease, so a high index of suspicion is important, and sputum should be obtained for evaluation even if chest radiographs are negative. TB diagnosis is similar in patients with and without TB, relying on smear, culture, and nucleic acid amplification tests, which are the initial tests of choice. TSTs and IGRAs should not be used in the evaluation of active TB disease since these tests are often negative with active disease. Though not always performed in resource-limited settings, drug susceptibility testing should be performed on all TB isolates from HIV-positive patients. Urine lipoarabinomannan testing may also be helpful in HIV-positive patients with disseminated disease. Treatment of TB in HIV-infected patients is similar to that of TB in HIV-negative patients except that daily therapy is required for all coinfected patients, vitamin B6 supplementation should be given to all coinfected patients receiving isoniazid to reduce peripheral neuropathy, and specific attention needs to be paid to drug-drug interactions between rifamycins and many classes of antiretrovirals. In patients requiring ART that contains ritonavir or cobicistat, this can be managed by the use of rifabutin at 150 mg daily in place of rifampin. For newly diagnosed coinfected patients, mortality is lower if treatment is provided in parallel, rather than serially, with treatment initiation within 2 weeks preferred for those with CD4 counts of <50 and within 8 to 12 weeks for those with higher CD4 counts. When TB immune reconstitution inflammatory syndrome occurs, patients can often be treated symptomatically with nonsteroidal anti-inflammatory drugs, but a minority will benefit from steroids. Generally, patients who do not have space-occupying lesions such as occurs in TB meningitis do not require cessation of therapy.

[Efficacy of the treatment and secondary antifungal prophylaxis in AIDS-related histoplasmosis. Experience at the Francisco J. Muñiz Infectious Diseases Hospital in Buenos Aires]

BACKGROUND

Classic histoplasmosis is a systemic endemic mycosis due to Histoplasma capsulatum var. capsulatum. A significant reduction in the morbidity and mortality of AIDS-related histoplasmosis has been observed since the introduction of highly active antiretroviral therapy (HAART) and secondary antifungal prophylaxis.

AIMS

The aim of this study was to determine the current state of prognosis and treatment response of HIV-positive patients with histoplasmosis in the Francisco J. Muñiz Infectious Diseases Hospital in Buenos Aires City.

METHODS

A retrospective study was conducted using the demographic, clinical, immunological and treatment data of 80 patients suffering from AIDS-related histoplasmosis.

RESULTS

Of the 80 cases studied 65 were male, the median age was 36 years, with 73.7% of the patients being drug addicts, 82.5% of the patients was not receiving HAART at diagnosis, and 58.7% of the cases had less than 50 CD4+ cells/μl at the beginning of the treatment. The initial phase of treatment consisted of intravenous amphotericin B and/or oral itraconazole for 3 months, with 78.7% of the cases showing a good clinical response. Only 26/63 patients who were discharged from hospital continued with the follow-up of the HAART, secondary prophylaxis with itraconazole or amphotericin B. Secondary prophylaxis was stopped after more than one year of HAART if the patients were asymptomatic, had two CD₄+ cell counts greater than 150cells/μl, and undetectable viral loads. No relapses were observed during a two-year follow up after prophylaxis was stopped.

CONCLUSIONS

The treatment of histoplasmosis in HIV-positive patients was effective in 78.8% of the cases. The combination of HAART and secondary antifungal prophylaxis is safe, well tolerated, and effective. The low adherence of patients to HAART and the lack of laboratory kits for rapid histoplasmosis diagnosis should be addressed in the future. The usefulness of primary antifungal prophylaxis for cryptococcosis and histoplasmosis HIV-positive patients should be studied.

Diagnosis and Treatment of Leishmaniasis: Clinical Practice Guidelines by the Infectious Diseases Society of America (IDSA) and the American Society of Tropical Medicine and Hygiene (ASTMH)

It is important to realize that leishmaniasis guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. The IDSA and ASTMH consider adherence to these guidelines to be voluntary, with the ultimate determinations regarding their application to be made by the physician in the light of each patient's individual circumstances.

Adding a single low-dose of primaquine (0.25 mg/kg) to artemether-lumefantrine did not compromise treatment outcome of uncomplicated Plasmodium falciparum malaria in Tanzania: a randomized, single-blinded clinical trial

Background

The World Health Organization (WHO) recently recommended the addition of a single low-dose of the gametocytocidal drug primaquine (PQ) to artemisinin-based combination therapy (ACT) in low transmission settings as a component of pre-elimination or elimination programmes. However, it is unclear whether that influences the ACT cure rate. The study assessed treatment outcome of artemether-lumefantrine (AL) plus a single PQ dose (0.25 mg/kg) versus standard AL regimen for treatment of acute uncomplicated Plasmodium falciparum malaria in Tanzania.

Methods

A randomized, single-blinded, clinical trial was conducted in Yombo, Bagamoyo district, Tanzania. Acute uncomplicated P. falciparum malaria patients aged ≥1 year, with the exception of pregnant and lactating women, were enrolled and treated with AL plus a single PQ dose (0.25 mg/kg) or AL alone under supervision. PQ was administered together with the first AL dose. Clinical and laboratory assessments were performed at 0, 8, 24, 36, 48, 60, and 72 h and on days 7, 14, 21, and 28. The primary end-point was a polymerase chain reaction (PCR)-adjusted adequate clinical and parasitological response (ACPR) on day 28. Secondary outcomes included: fever and asexual parasitaemia clearance, proportion of patients with PCR-determined parasitaemia on day 3, and proportion of patients with Pfmdr1 N86Y and Pfcrt K76T on days 0, 3 and day of recurrent infection.

Results

Overall 220 patients were enrolled, 110 were allocated AL + PQ and AL, respectively. Parasite clearance by microscopy was fast, but PCR detectable parasitaemia on day 3 was 31/109 (28.4 %) and 29/108 (26.9 %) in patients treated with AL + PQ and AL, respectively (p = 0.79). Day 28 PCR-adjusted ACPR and re-infection rate was 105/105 (100 %) and 101/102 (99 %) (p = 0.31), and 5/107 (4.7 %) and 5/8 (4.8 %) (p = 0.95), in AL + PQ and AL arm, respectively. There was neither any statistically significant difference in the proportion of Pfmdr1 N86Y or Pfcrt K76T between treatment arms on days 0, 3 and day of recurrent infection, nor within treatment arms between days 0 and 3 or day 0 and day of recurrent infection.

Conclusion

The new WHO recommendation of adding a single low-dose of PQ to AL did not compromise treatment outcome of uncomplicated P. falciparum malaria in Tanzania.

Trial registration number NCT02090036

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-016-1430-3) contains supplementary material, which is available to authorized users.

Management of severe non-TB bacterial infection in HIV-infected adults

Despite widespread antiretroviral therapy use, severe bacterial infections (SBI) in HIV-infected adults continue to cause significant morbidity and mortality globally. Four main pathogens account for the majority of documented SBI: Streptococcus pneumoniae, non-typhoidal strains of Salmonella enterica, Escherichia coli and Staphylococcus aureus. The epidemiology of SBI is dynamic, both in developing countries where, despite dramatic successes in antiretroviral therapy, coverage is far from complete, and in settings in both resource-poor and resource-rich countries where antiretroviral therapy failure is becoming increasingly common. Throughout the world, this complexity is further compounded by rapidly emerging antimicrobial resistance, making management of SBI very challenging in these vulnerable patients. We review the causes and treatment of SBI in HIV-infected people and discuss future developments in this field.

Computational pharmacokinetics/pharmacodynamics of rifampin in a mouse tuberculosis infection model

One critical approach to preclinical evaluation of anti-tuberculosis (anti-TB) drugs is the study of correlations between drug exposure and efficacy in animal TB infection models. While such pharmacokinetic/pharmacodynamic (PK/PD) studies are useful for the identification of optimal clinical dosing regimens, they are resource intensive and are not routinely performed. A mathematical model capable of simulating the PK/PD properties of drug therapy for experimental TB offers a way to mitigate some of the practical obstacles to determining the PK/PD index that best correlates with efficacy. Here, we present a preliminary physiologically based PK/PD model of rifampin therapy in a mouse TB infection model. The computational framework integrates whole-body rifampin PKs, cell population dynamics for the host immune response to Mycobacterium tuberculosis infection, drug-bacteria interactions, and a Bayesian method for parameter estimation. As an initial application, we calibrated the model to a set of available rifampin PK/PD data and simulated a separate dose fractionation experiment for bacterial killing kinetics in the lungs of TB-infected mice. The simulation results qualitatively agreed with the experimentally observed PK/PD correlations, including the identification of area under the concentration-time curve as best correlating with efficacy. This single-drug framework is aimed toward extension to multiple anti-TB drugs in order to facilitate development of optimal combination regimens.

Pharmacokinetics of efavirenz and treatment of HIV-1 among pregnant women with and without tuberculosis coinfection

BACKGROUND

Pregnancy and tuberculosis treatment or prophylaxis can affect efavirenz pharmacokinetics, maternal human immunodeficiency virus type 1 (HIV-1) treatment outcomes, and mother-to-child transmission (MTCT) risk.

METHODS

We evaluated a prospective cohort of pregnant, HIV-infected women with and without tuberculosis in Soweto, South Africa. Pharmacokinetic sampling was performed at gestation week 37 and during the postpartum period. Efavirenz trough concentrations (Cmin) were predicted using population pharmacokinetic models. HIV-viral load was measured at delivery for mothers and at 6 weeks of age for infants.

RESULTS

Ninety-seven women participated; 44 had tuberculosis. Median efavirenz Cmin during pregnancy was 1.35 µg/mL (interquartile range [IQR], 0.90-2.07 µg/mL; 27% had an efavirenz Cmin of < 1 µg/mL), compared with a median postpartum value of 2.00 µg/mL (IQR, 1.40-3.59 µg/mL; 13% had an efavirenz Cmin of < 1 µg/mL). A total of 72% of pregnant women with extensive CYP2B6 genotypes had an efavirenz Cmin of <1 µg/mL. Rifampin did not reduce the efavirenz Cmin. Isoniazid (for prophylaxis or treatment), though, reduced the rate of efavirenz clearance. At delivery, median durations of ART were 13 weeks (IQR, 9-18 weeks) and 21 weeks (IQR, 13-64 weeks) for women with and those without tuberculosis, respectively; 55% and 83%, respectively, had a viral load of <20 copies/mL (P = .021). There was 1 case of MTCT.

CONCLUSIONS

Pregnancy increased the risk of low efavirenz concentrations, but MTCT was rare. A detectable HIV-viral load at delivery was more common among pregnant women with tuberculosis, in whom ART was generally initiated later.

Fixed dose combination of arterolane and piperaquine: a newer prospect in antimalarial therapy

Malaria has been very prevalent vector-borne disease in India and until date bears enormous implications on health care services of the country. Over the period of time, the development of resistance to traditional antimalarials like chloroquine has been posed as major deterrent in efforts of malaria control. As the drug resistance is today universally prevalent, especially in Plasmodium falciparum species, major burden of malarial control resides with the new artemisinin drug class. However, arterolane is one of the first fully synthetic non-artemisinin antimalarial compound with rapid schizontocidal activity, hence offering an alternative to artemisinin drugs in malaria control. Piperaquine is a synthetic bisquinoline (4-amioquinoline Antimalarial) with slow and longer schizontocidal activity. Therefore their combination has been shown to provide rapid parasitemic clearance and quick relief of most malaria-related symptoms along with prevention of recrudescences. This combination was approved by Drugs Controller General of India in 2011 for treatment of uncomplicated P. falciparum malaria. The article is aimed at to review this newer prospect in antimalarial therapy for which comprehensive database search was done in Google, Google Scholar, PubMed using the terms “Malaria,” “Arterolane,” “OZ277,” “Piperaquine,” and “Artemisinin combination therapy.” A total of 323 articles were screened and 28 articles were considered for this review along with the World Health Organization and National malarial program guidelines.

Dolutegravir: a new option for HIV treatment

ABSTRACT: 

The need for new strategies for treating HIV-1 infection has led to the development of a number of new drugs. The aim of this article is to review the latest results of clinical trials of dolutegravir, an integrase inhibitor whose efficacy, tolerability and safety have been confirmed in treatment-naive and treatment-experienced patients. The findings, together with its high genetic barrier and limited interactions with other drugs, indicate that dolutegravir will play an important role in the future treatment of HIV infection.

Computational pharmacology of rifampin in mice: an application to dose optimization with conflicting objectives in tuberculosis treatment

Dose selection for rifampin in the treatment of active pulmonary tuberculosis (TB) illustrates some of the challenges for dose optimization within multidrug therapies. Rifampin-based anti-TB regimens are often combined with antiretroviral therapies to treat human immunodeficiency virus (HIV) coinfection. The potent cytochrome P450 (CYP) enzyme inducing properties of rifampin give rise to significant drug-drug interactions, the minimization of which by limiting the dose, conflicts with the maximization of bacterial killing by increasing the dose. Such multiple and conflicting objectives lead to a set of trade-off optimal solutions for dose optimization rather than a single best solution. Here, we combine pharmacokinetic/pharmacodynamic (PK/PD) modeling with multiobjective optimization to quantitatively explore trade-offs between therapeutic and adverse effects of optimal dosing for the example of rifampin in TB-infected mice. The PK/PD model describes rifampin concentrations in plasma and liver following oral administration together with hepatic CYP enzyme induction and bacterial killing kinetics. We include optimization objectives descriptive of antimicrobial efficacy, CYP-mediated drug-drug interactions, and drug exposure-dependent toxicity. Results show non-conventional dosing scenarios that allow for increased efficacy relative to uniform dosing without increasing drug-drug interactions. Additionally, we find currently employed dosages for rifampin to be nearly optimal with respect to trade-offs between efficacy and toxicity. While limited by the accuracy and applicability of the PK/PD model, these results provide an avenue for experimental investigation of complex dose optimization problems. This method can be extended to include additional drugs and optimization objectives, and may provide a useful tool for individualized medicine.

Phase I safety, pharmacokinetics, and pharmacogenetics study of the antituberculosis drug PA-824 with concomitant lopinavir-ritonavir, efavirenz, or rifampin

There is an urgent need for new antituberculosis (anti-TB) drugs, including agents that are safe and effective with concomitant antiretrovirals (ARV) and first-line TB drugs. PA-824 is a novel antituberculosis nitroimidazole in late-phase clinical development. Cytochrome P450 (CYP) 3A, which can be induced or inhibited by ARV and antituberculosis drugs, is a minor (∼20%) metabolic pathway for PA-824. In a phase I clinical trial, we characterized interactions between PA-824 and efavirenz (arm 1), lopinavir/ritonavir (arm 2), and rifampin (arm 3) in healthy, HIV-uninfected volunteers without TB disease. Participants in arms 1 and 2 were randomized to receive drugs via sequence 1 (PA-824 alone, washout, ARV, and ARV plus PA-824) or sequence 2 (ARV, ARV with PA-824, washout, and PA-824 alone). In arm 3, participants received PA-824 and then rifampin and then both. Pharmacokinetic sampling occurred at the end of each dosing period. Fifty-two individuals participated. Compared to PA-824 alone, plasma PA-824 values (based on geometric mean ratios) for maximum concentration (Cmax), area under the concentration-time curve from 0 to 24 h (AUC0-24), and trough concentration (Cmin) were reduced 28%, 35%, and 46% with efavirenz, 13%, 17%, and 21% with lopinavir-ritonavir (lopinavir/r) and 53%, 66%, and 85% with rifampin, respectively. Medications were well tolerated. In conclusion, lopinavir/r had minimal effect on PA-824 exposures, supporting PA-824 use with lopinavir/r without dose adjustment. PA-824 exposures, though, were reduced more than expected when given with efavirenz or rifampin. The clinical implications of these reductions will depend upon data from current clinical trials defining PA-824 concentration-effect relationships. (This study has been registered at ClinicalTrials.gov under registration no. NCT01571414.).

Can plant biotechnology help break the HIV-malaria link?

The population of sub-Saharan Africa is at risk from multiple, poverty-related endemic diseases. HIV and malaria are the most prevalent, but they disproportionately affect different groups of people, i.e. HIV predominantly affects sexually-active adults whereas malaria has a greater impact on children and pregnant women. Nevertheless, there is a significant geographical and epidemiological overlap which results in bidirectional and synergistic interactions with important consequences for public health. The immunosuppressive effects of HIV increase the risk of infection when individuals are exposed to malaria parasites and also the severity of malaria symptoms. Similarly, acute malaria can induce a temporary increase in the HIV viral load. HIV is associated with a wide range of opportunistic infections that can be misdiagnosed as malaria, resulting in the wasteful misuse of antimalarial drugs and a failure to address the genuine cause of the disease. There is also a cumulative risk of toxicity when antiretroviral and antimalarial drugs are given to the same patients. Synergistic approaches involving the control of malaria as a strategy to fight HIV/AIDS and vice versa are therefore needed in co-endemic areas. Plant biotechnology has emerged as a promising approach to tackle poverty-related diseases because plant-derived drugs and vaccines can be produced inexpensively in developing countries and may be distributed using agricultural infrastructure without the need for a cold chain. Here we explore some of the potential contributions of plant biotechnology and its integration into broader multidisciplinary public health programs to combat the two diseases in developing countries.

Disseminated histoplasmosis in HIV-infected patients: determinants of relapse and mortality in a north-eastern area of Brazil

Many relapses and deaths resulting from disseminated histoplasmosis (DH) in acquired immunodeficiency syndrome (AIDS) patients have been observed in an endemic area in north-eastern Brazil. The objective of this study was to evaluate the risk factors associated with the clinical outcomes of DH/AIDS coinfection in patients from the state of Ceará, Brazil. A retrospective cohort of AIDS patients, after their hospital discharge due to first DH episode in the period 2002-2008, was followed until December 31, 2010, to investigate the factors associated with relapse and mortality. A total of 145 patients were evaluated in the study. Thirty patients (23.3%) relapsed and the overall mortality was 30.2%. The following variables were significantly (P < 0.05) associated with relapse and overall mortality (univariate analysis): non-adherence to highly active antiretroviral therapy (HAART), irregular use of an antifungal, non-recovery of the CD4+ count and having AIDS before DH; histoplasmosis relapse was also significantly associated with mortality. In the multivariate analysis, non-adherence to HAART was the independent risk factor that was associated with both relapse (Adj OR = 6.28) and overall mortality (Adj OR = 8.03); efavirenz usage was discovered to be significant only for the overall mortality rate (Adj OR = 4.50). Adherence to HAART was the most important variable that influenced the outcomes in this specific population.

Tolerability and safety of artesunate-amodiaquine and artemether-lumefantrine fixed dose combinations for the treatment of uncomplicated Plasmodium falciparum malaria: two open-label, randomized trials in Nimba County, Liberia

BACKGROUND

Safety surveillance of widely used artemisinin-based combination therapy (ACT) is essential, but tolerability data in the over five years age group are largely anecdotal.

METHODS

Two open-label, randomized trials were conducted in Nimba County, Liberia: i) the main tolerability trial with 1,000 Plasmodium falciparum malaria patients aged over five years (Study-T), and, ii) an efficacy trial with a secondary objective of collecting tolerability data among 300 children age six to 59 months (Study-E). In both studies patients were randomized to fixed-dose artesunate-amodiaquine (ASAQ Winthrop®) or artemether-lumefantrine (AL, Coartem®), respectively. Clinical- and laboratory-adverse events (AEs) were recorded until day 28.

RESULTS

Study-T: most patients experienced at least one AE. Severe AEs were few, primarily asymptomatic blood system disorders or increased liver enzyme values. No treatment or study discontinuation occurred. Mild or moderate fatigue (39.8% vs 16.3%, p < 0.001), vomiting (7.1% vs 1.6%, p < 0.001), nausea (3.2% vs 1.0%, p = 0.01), and anaemia (14.9% vs 9.8%, p = 0.01) were more frequently recorded in the ASAQ versus AL arm. Study-E: mild or moderate AEs were common, including anaemia, fatigue, vomiting or diarrhoea. The few severe events were asymptomatic blood system disorders and four clinical events (pneumonia, malaria, vomiting and stomatitis).

CONCLUSION

Both ASAQ and AL were well tolerated in patients of all age groups. No unexpected AEs occurred. Certain mild or moderate AEs were more frequent in the ASAQ arm. Standardised safety surveillance should continue for all forms of ACT.

TRIAL REGISTRATION

The protocols were registered with Current Controlled Trials, under the identifier numbers ISRCTN40020296, ISRCTN51688713, (http://www.controlled-trials.com).

Tolerability of mefloquine intermittent preventive treatment for malaria in HIV-infected pregnant women in Benin

OBJECTIVE

To investigate the tolerability of mefloquine intermittent preventive treatment (MQ IPTp) for malaria in HIV-infected pregnant women compared with HIV-negative women.

DESIGN

Prospective cohort study comparing samples of HIV-negative and HIV-infected pregnant women from 2 clinical trials conducted in Benin.

METHODS

One hundred and three HIV-infected women from the ongoing PACOME trial were compared with 421 HIV-negative women from a former trial, both trials aiming to evaluate the efficacy and tolerability of MQ IPTp, administered at the dose of 15 mg/kg. Descriptive analysis compared the proportion of women reporting at least 1 adverse reaction, according to HIV status. Multilevel logistic regression identified factors associated with the probability of reporting an adverse reaction for each MQ intake.

RESULTS

Dizziness and vomiting were the most frequent adverse reactions. Adverse reactions were less frequent in HIV-infected women (65% versus 78%, P = 0.009). In multilevel analysis, HIV infection [odds ratio (OR) = 0.23, 95% confidence interval (CI) = 0.08 to 0.61] decreased the risk for adverse reactions, whereas detectable viral load (OR = 2.46, 95% CI = 1.07 to 5.66), first intake (versus further intakes, OR = 5.26, 95% CI = 3.70 to 7.14), older age (OR = 1.62, 95% CI = 1.13 to 2.32), and higher education level (OR = 1.71, 95% CI = 1.12 to 2.61) increased the risk. Moderate and severe adverse reactions were more frequent when antiretrovirals were started concomitantly with a MQ intake.

CONCLUSIONS

This study provides reassuring data on the use of MQ IPTp in HIV-infected pregnant women. However frequent, adverse reactions remained moderate and did not impair adherence to MQ IPTp. In this high-risk group, MQ might be an acceptable alternative in case sulfadoxine-pyrimethamine loses its efficacy for intermittent preventive treatment.

The frequency of malaria is similar among women receiving either lopinavir/ritonavir or nevirapine-based antiretroviral treatment

HIV protease inhibitors (PIs) show antimalarial activity in vitro and in animals. Whether this translates into a clinical benefit in HIV-infected patients residing in malaria-endemic regions is unknown. We studied the incidence of malaria, as defined by blood smear positivity or a positive Plasmodium falciparum histidine-rich protein 2 antigen test, among 444 HIV-infected women initiating antiretroviral treatment (ART) in the OCTANE trial (A5208; ClinicalTrials.gov: NCT00089505). Participants were randomized to treatment with PI-containing vs. PI-sparing ART, and were followed prospectively for ≥48 weeks; 73% also received cotrimoxazole prophylaxis. PI-containing treatment was not associated with protection against malaria in this study population.

Guidelines on the treatment of chronic coinfection by Trypanosoma cruzi and HIV outside endemic areas

As a result of population migration, Chagas disease is no longer limited to the North and South American continents. In HIV-infected patients, chronic infection by Trypanosoma cruzi behaves as an opportunistic infection in severely immunosuppressed patients and is responsible for high morbidity and mortality. Unlike other opportunistic infections, information on the natural history, diagnosis, treatment, and prevention of Chagas disease is scarce. Spain has the highest number of cases of Chagas disease outside the North and South American continents, and coinfection with HIV is increasingly prevalent. In this article, the Spanish Society for Tropical Medicine and International Health (Sociedad Española de Medicina Tropical y Salud Internacional) reviews the current situation of coinfection with HIV and T. cruzi infection and provides guidelines on the diagnosis, treatment, and prevention in areas where Chagas disease is not endemic. It also identifies areas of uncertainty where additional research is necessary.

Nuclear receptor-mediated induction of CYP450 by antiretrovirals: functional consequences of NR1I2 (PXR) polymorphisms and differential prevalence in whites and sub-Saharan Africans

BACKGROUND

Antiretroviral therapy including HIV protease inhibitors and nonnucleoside reverse transcriptase inhibitors can both inhibit and induce expression of cytochrome P450s, potentially leading to drug interactions. However, information is lacking on the impact of genetic polymorphism on this interaction.

METHODS

This study examines the prevalence of 33 polymorphisms in NR1I2 (pregnane X receptor [PXR]), CYP3A4, and CYP2B6 in 1013 white and sub-Saharan African patients with HIV; explores the inductive ability of 16 antiretrovirals on CYP3A4 and CYP2B6 promoter activity through nuclear receptors PXR and constitutive androstane receptor (CAR); and evaluates the influence of naturally occurring PXR genetic variants on antiretroviral activation.

RESULTS

Seventeen polymorphisms were present at different frequencies between the two ethnicities. Darunavir, fosamprenavir, lopinavir, nelfinavir, tipranavir, efavirenz, and abacavir increased CYP3A4 and/or CYP2B6 promoter activity, some through constitutive androstane receptor but mainly through PXR. Addition of low-dose ritonavir enhanced levels of CYP promoter activity for several protease inhibitors. Some PXR variants displayed lower fosamprenavir- and lopinavir-induced CYP3A4 promoter activity than the PXR reference sequence, whereas efavirenz and nelfinavir induction was unchanged.

CONCLUSIONS

The presence of NR1I2 polymorphisms can alter the induction of CYP3A4 and CYP2B6 promoter activity, potentially adding to the unpredictable nature of antiretroviral drug interactions. These polymorphisms differ in prevalence between whites and sub-Saharan Africans.

Expanding the Antimalarial Drug Arsenal-Now, But How?

The number of available and effective antimalarial drugs is quickly dwindling. This is mainly because a number of drug resistance-associated mutations in malaria parasite genes, such as crt, mdr1, dhfr/dhps, and others, have led to widespread resistance to all known classes of antimalarial compounds. Unfortunately, malaria parasites have started to exhibit some level of resistance in Southeast Asia even to the most recently introduced class of drugs, artemisinins. While there is much need, the antimalarial drug development pipeline remains woefully thin, with little chemical diversity, and there is currently no alternative to the precious artemisinins. It is difficult to predict where the next generation of antimalarial drugs will come from; however, there are six major approaches: (i) re-optimizing the use of existing antimalarials by either replacement/rotation or combination approach; (ii) repurposing drugs that are currently used to treat other infections or diseases; (iii) chemically modifying existing antimalarial compounds; (iv) exploring natural sources; (v) large-scale screening of diverse chemical libraries; and (vi) through parasite genome-based ("targeted") discoveries. When any newly discovered effective antimalarial treatment is used by the populus, we must maintain constant vigilance for both parasite-specific and human-related factors that are likely to hamper its success. This article is neither comprehensive nor conclusive. Our purpose is to provide an overview of antimalarial drug resistance, associated parasite genetic factors (1. Introduction; 2. Emergence of artemisinin resistance in P. falciparum), and the antimalarial drug development pipeline (3. Overview of the global pipeline of antimalarial drugs), and highlight some examples of the aforementioned approaches to future antimalarial treatment. These approaches can be categorized into "short term" (4. Feasible options for now) and "long term" (5. Next generation of antimalarial treatment-Approaches and candidates). However, these two categories are interrelated, and the approaches in both should be implemented in parallel with focus on developing a successful, long-lasting antimalarial chemotherapy.

Intermittent preventive treatment of malaria in pregnancy: at the crossroads of public health policy

The intermittent preventive treatment of malaria in pregnancy (IPTp) with sulphadoxine-pyrimethamine (SP) has been a key component of the focused antenatal care package for nearly a decade, reducing the burden of low birthweight attributable to malaria in sub-Saharan Africa. However, SP has lost parasite sensitivity in many sub-Saharan locations during the same period, rendering its beneficial effect in IPTp debatable. Malaria transmission has also declined in some epidemiological settings. There is no evidence to suggest, however, that the risk of malaria in pregnancy without preventive measures has declined in the same locations. Thus, the urgency to identify efficacious drugs and/or new strategies to prevent malaria in pregnancy remains as great as ever. We summarise the results of recently published SP-IPTp studies from areas of high drug resistance and/or low malaria transmission. We also present the evidence for mefloquine and azithromycin-based combinations (ABCs), two leading drug options to replace SP in IPTp. We discuss optimal dosing for ABCs and their likely protection against several sexually transmitted and reproductive tract infections. We also summarise data from a diagnosis-based alternative to IPTp known as the intermittent screening and treatment (IST) for malaria. Clinical and operational research is urgently needed to compare birth outcomes achieved by IPTp with ABCs vs. IST using an efficacious antimalarial therapy.