[Use of herbal remedies among HIV-infected patients: patterns and correlates]

Complementary and alternative medicine in HIV care: frequency of consumption, risks and interactions with antiretroviral therapy

OBJECTIVES

People living with HIV (PLWH) are common users of complementary and alternative medicine (CAM). The main objective of this study was to study the frequency and patterns of CAM natural products use in a large cohort of PLWH and to identify potential drug-drug interactions (DDIs) and the impact on their antiretroviral treatment (ART) adherence and efficacy.

METHODS

This was a cross-sectional multicenter survey including 420 PLWH from different Spanish hospitals. Participants completed a face-to-face questionnaire on CAM consumption and different sociodemographic and clinical data were collected. DDIs between CAM and ART were identified and classified according to the Liverpool University Database and patient factors related to CAM consumption were assessed.

RESULTS

420 participants were included (82.6% male, mean age 47 years); 209 patients (49.8%) were taking at least one CAM. The most consumed CAM were green, black and red tea (n=146, 25.4%), ginger (n=26, 4.5%), fish oil (n=25, 4.4%) and cannabis (n=24, 4.2%). An ART based on integrase inhibitors was the only factor independently associated with CAM consumption (OR 1.54, 95% CI 1.04 to 2.26). 50 potential CAM-ART interactions in 43 (20.6%) patients taking CAM were identified, being clinically significant in 80% of the cases. CAM products most frequently involved with a potential significant DDI were supplements containing divalent cations (n=11) and garlic (n=7). No differences in ART efficacy and adherence were observed between patients with and without CAM consumption.

CONCLUSIONS

Almost 50% of patients were taking at least one CAM product and its use was associated with an integrase inhibitor based ART. One out of every six patients was at risk of presenting with an interaction between a CAM and their ART, confirming the need to review continuously the use of CAM as part of the medication review process.

Potentially inappropriate prescriptions and therapeutic complexity in older HIV patients with comorbidities

BACKGROUND

The prolonged current survival of human immunodeficiency virus (HIV) patients exposes them to new problems arising from the comorbidities they face.

OBJECTIVES

To describe the situation of comorbidities, polypharmacy, therapeutic complexity and adherence in people living with HIV over 65 years of age and to assess the presence of potentially inappropriate prescriptions (PIP) by applying deprescription criteria.

METHODS

Observational study including HIV people (> 65 years) from a university tertiary level hospital. Demographic, clinical and pharmacotherapeutic characteristics of the patients and their treatments were studied. The prevalence of polypharmacy (> 5 medications) and the pharmacotherapy complexity, quantified by the Medication Regimen Complexity Index (MRCI), were calculated. Therapeutic adherence was assessed by the Simplified Medication Adherence Questionnaire (SMAQ) and the medication possession ratio, according to prescription dispensing records. The Screening Tool of Older People's Prescriptions (STOPP) and List of Evidence-baSed depreScribing for CHRONic patients (LESS-CHRON) criteria were applied to identify PIP.

MAIN OUTCOME MEASURE

PIP in elderly people living with HIV.

RESULTS

Thirty patients were included, 73% of whom were men, with a median age of 71 years (IQR 67 - 76) and a median duration of infection of 17 years (IQR, 9 - 21). Seventy percent of the patients suffered from dyslipemia, 66.7% from hypertension, 43.3% from diabetes and 26.7% from mental health disorders. Seventy percent of the patients took more than 5 medications and 30% more than 10. The MRCI of concomitant medications was higher (18.3 points) than the MRCI of antiretroviral therapy (5.1 points), 66.7% of the studied population was classified as adherent. Finally, 70% of the patients present some PIP according to the STOPP or LESS-CHRON criteria. The polypharmacy was significantly associated (p = 0.008) with meeting deprescription criteria.

CONCLUSION

The elderly people living with HIV present numerous comorbidities and met the criteria for polypharmacy. Their pharmacotherapy complexity is mainly determined by the concomitant treatments. There is a high prevalence of meeting deprescription criteria in people living with HIV over the age of 65 and a clear relationship between polypharmacy and deprescription. The optimization of pharmacotherapy is necessary in this population.

Possible Drug-Herb Interaction between Herbal Supplement Containing Horsetail ( Equisetum arvense) and Antiretroviral Drugs

The use of alternative medicines, including herbs, is common among HIV-positive patients, even in those on antiretroviral treatment. Equisetum arvense, known as "horsetail," is mainly used for its diuretic properties. There are limited data about the pharmacological properties of this compound and the potential drug-herb interactions. The authors report 2 cases in which a possible drug-herb interaction may have led to virological breakthrough in patients who were maintained on the same regimen for many years, including lamivudine (3TC)/zidovudine (ZDV)/efavirenz (EFV) and emtricitabine (FTC)/tenofovir (TDF)/EFV, respectively. Therefore, a drug-herb interaction may be expected when these agents are taken concurrently. Until additional data are available, the authors advise clinicians to avoid this combination when possible.

A Comprehensive Review of Recent Studies on Herb-Drug Interaction: A Focus on Pharmacodynamic Interaction

OBJECTIVES

The concomitant use of herbal and conventional drugs accelerates the possibility of clinically significant herb-drug interactions (HDIs). This paper aims to analyze the current status of HDI studies worldwide and to review studies on HDI-induced pharmacodynamic (PD) interactions.

METHODS

HDI studies published from 2000 to 2014 and indexed in PubMed were categorized according to publication year, area/country, study methods and objectives, and disease categories. The reviewed studies focused on HDI-induced PD; each PD interaction with concurrent use of approximately 100 herbal drugs and 70 conventional drugs was summarized. All PD-related articles were categorized according to four characteristics: herbal drugs, conventional drugs, types of PD interaction, and type of study. Among them, 17 well-designed clinical studies were evaluated by using the Jadad Quality Assessment Scale.

RESULTS

The number of HDI reports has gradually increased since 2000, with a primary focus on neoplasms and diseases of the circulatory system. Most of these investigated pharmacokinetic reactions, such as cytochrome P450 enzyme metabolism, with fewer reports investigating PD. Most PD interaction studies investigated warfarin, ginkgo leaves, and St. John's wort. An evaluation of 17 studies revealed a generally positive view of PD effects involving synergism or reduced toxicity and a high average quality score (>3 points on a 0-5 scale).

CONCLUSIONS

These results demonstrate that most HDI studies so far have examined PK interactions and have been limited to very few conventional drugs and herbal drugs. This suggests that more studies focusing on PD are necessary to understand interactions between commonly used herbal and conventional drugs.

Application of Caco-2 cell line in herb-drug interaction studies: current approaches and challenges

The Caco-2 model is employed in pre-clinical investigations to predict the likely gastrointestinal permeability of drugs because it expresses cytochrome P450 enzymes, transporters, microvilli and enterocytes of identical characteristics to the human small intestine. The FDA recommends this model as integral component of the Biopharmaceutics Classification System (BCS). Most dedicated laboratories use the Caco-2 cell line to screen new chemical entities through prediction of its solubility, bioavailability and the possibility of drug-drug or herb-drug interactions in the gut lumen. However, challenges in the inherent characteristics of Caco-2 cell and inter-laboratory protocol variations have resulted to generation of irreproducible data. These limitations affect the extrapolation of data from pre-clinical research to clinical studies involving drug-drug and herb-drug interactions. This review addresses some of these caveats and enumerates the plausible current and future approaches to reduce the anomalies associated with Caco-2 cell line investigations focusing on its application in herb-drug interactions.

A binational comparison of HIV provider attitudes towards the use of complementary and alternative medicine among HIV-positive Latino patients receiving care in the US-Mexico border region

Use of complementary and alternative medicine (CAM) is common among Latinos living with HIV in the United States (US)-Mexico border region. Health providers may vary in their approach to communicating acceptance or non acceptance of CAM use, which can undermine patient confidence in disclosing CAM use. Patient-provider communication about CAM is important because certain types of CAM can affect antiretroviral therapy (ART) adherence. We undertook the present binational study to understand US and Mexican provider beliefs, and perceptions surrounding CAM use among Latino patients, and to learn if and how CAM communication occurs. Between July and December 2010, we conducted in-depth, qualitative interviews in Tijuana and San Diego. Analysis procedures drew upon principles of Grounded Theory. The sample was comprised of 19 HIV-health care providers, including 7 women and 12 men. Emerging CAM-related themes were: Provider's perceptions, attitudes and knowledge about CAM; CAM types and modalities; and patient-provider CAM communication. Many clinicians were uncomfortable supporting CAM use with their patients. San Diego providers reported more frequent instances of CAM use among Latino patients than Tijuana providers. Providers from both cities reported that patients infrequently disclose CAM use and almost half do not routinely ask patients about CAM practices. Most of the providers acknowledged that they lack information about CAM, and are concerned about the drug interaction as well as the effects of CAM on adherence. Our findings have important implications for understanding provider communication surrounding CAM use in a highly transnational population and context. Because CAM use may undermine ART adherence and is highly prevalent among Latinos, provider communication about CAM is critical to improved health outcomes among HIV-positive Latinos. Considering the significant growth of US Latinos, especially in the US-Mexico border region, assessment of Mexican and US provider training and communication needs surrounding Latino patient CAM use is warranted.

Herb-drug interaction between Echinacea purpurea and etravirine in HIV-infected patients

The aim of this open-label, fixed-sequence study was to investigate the potential of the botanical supplement Echinacea purpurea to interact with etravirine, a nonnucleoside reverse transcriptase inhibitor of HIV. Fifteen HIV-infected patients receiving antiretroviral therapy with etravirine (400 mg once daily) for at least 4 weeks were included. E. purpurea root/extract-containing capsules were added to the antiretroviral treatment (500 mg every 8 h) for 14 days. Etravirine concentrations in plasma were determined by high-performance liquid chromatography immediately before and 1, 2, 4, 6, 8, 10, 12, and 24 h after a morning dose of etravirine on day 0 and etravirine plus E. purpurea on day 14. Individual etravirine pharmacokinetic parameters were calculated by noncompartmental analysis and compared between days 0 and 14 by means of the geometric mean ratio (GMR) and its 90% confidence interval (CI). The median age was 46 years (interquartile range, 41 to 50), and the median body weight was 76 kg (interquartile range, 68 to 92). Echinacea was well tolerated, and all participants completed the study. The GMR for etravirine coadministered with E. purpurea relative to etravirine alone was 1.07 (90% CI, 0.81 to 1.42) for the maximum concentration, 1.04 (90% CI, 0.79 to 1.38) for the area under the concentration-time curve from 0 to 24 h, and 1.04 (90% CI, 0.74 to 1.44) for the concentration at the end of the dosing interval. In conclusion, the coadministration of E. purpurea with etravirine was safe and well tolerated in HIV-infected patients; our data suggest that no dose adjustment for etravirine is necessary.

Effect of milk thistle on the pharmacokinetics of darunavir-ritonavir in HIV-infected patients

The aim of this open-label, fixed-sequence study was to investigate the potential of the botanical supplement milk thistle (silymarin) to interact with the boosted protease inhibitor combination darunavir-ritonavir. Fifteen HIV-infected patients receiving antiretroviral therapy with darunavir-ritonavir (600/100 mg twice daily) for at least 4 weeks were included. Silymarin (150 mg every 8 h) was added to the antiretroviral treatment from days 1 to 14. Darunavir concentrations in plasma were determined by high-performance liquid chromatography immediately before and 1, 2, 4, 6, 8, 10, and 12 h after a morning dose of darunavir-ritonavir on day 0 and darunavir-ritonavir plus silymarin on day 14. Individual darunavir pharmacokinetic parameters were calculated by noncompartmental analysis and compared between days 0 and 14 by means of the geometric mean ratio (GMR) and its 90% confidence interval (CI). The median age was 48 years (interquartile range, 44 to 50 years), and the median body weight was 70 kg (interquartile range, 65 to 84 kg). Silymarin was well tolerated, and all participants completed the study. The GMRs for darunavir coadministered with silymarin relative to darunavir alone were 0.86 (90% CI, 0.70 to 1.05) for the area under the concentration-time curve from 0 to 12 h, 0.83 (90% CI, 0.80 to 0.98) for the maximum concentration, and 0.94 (90% CI, 0.73 to 1.19) for the concentration at the end of the dosing interval. In summary, coadministration of silymarin with darunavir-ritonavir seems to be safe in HIV-infected patients; no dose adjustment for darunavir-ritonavir seems to be necessary.