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

BACKGROUND: Contemporary first-line antiretrovirals have considerably reduced liability for clinically significant drug-drug interactions (DDI). This systematic review evaluates the prevalence of DDI among people receiving antiretrovirals across 3 decades. METHODS: We searched 3 databases for studies reporting the prevalence of clinically significant DDIs in patients receiving antiretrovirals published between January 1987 and July 2022. Clinically significant DDIs were graded by severity. All data extractions were undertaken by 2 independent reviewers, adjudicated by a third. RESULTS: Of 21,665 records returned, 13,474 were duplicates. After screening the remaining 13,596 abstracts against inclusion criteria, 122 articles were included for full-text analysis, from which a final list of 34 articles were included for data synthesis. The proportion of patients experiencing a clinically significant DDI did not change over time (P = 0.072). The most frequently reported classes of antiretrovirals involved in DDIs were protease inhibitors and non-nucleoside reverse transcriptase inhibitors; of note, integrase use in the most recent studies was highly variable and ranged between 0% and 89%. CONCLUSIONS: The absolute risk of DDIs has not decreased over the period covered. This is likely related to continued use of older regimens and an ageing cohort of patients. A greater reduction in DDI prevalence can be anticipated with broader uptake of regimens containing unboosted integrase inhibitors or non-nucleoside reverse transcriptase inhibitors.

The Collaborative Care Model: Realizing healthcare values and increasing responsiveness in the pharmacy workforce.

Healthcare values are fairly ubiquitous across the globe, focusing on caring and respect, patient health, excellence in care delivery, and multi-stakeholder collaboration. Many individual pharmacists embrace these core values. However, their ability to honor these values is significantly determined by the nature of the system in which they work. The paper starts by presenting the prevailing pharmacist workforce model, the 'Atomistic' Model, in Scotland, in which core roles are typically separated into hierarchically disaggregated jobs focused on one professional 'pillar': Clinician/Practice Provider; Educator; Leader/Manager; and Researcher. This skills-segregation yields a workforce of individuals working in isolation rather than collaborating, lacking a shared purpose. Key strategic flaws include suboptimal responsiveness to population needs, inconsistency/inequity of care, erosion of professional agency, and lower job satisfaction. It is conjectured that this results from a lack of congruence between values, professional ethos, and organizational structure. 'Atomism' culminates in a syndrome of widespread professional-level cognitive dissonance. The paper contrasts this with an emerging workforce vision, the Collaborative Care Model. This new model defines a systems-first-approach, built on the principle that all jobs must include all four professional 'pillars'. Vertical skills integration, involving education and task sharing, supports sustainability and succession planning. Horizontal skills integration (across practice, leadership/management, education, and research) is included to improve responsiveness to population need and individual professional agency. The working conditions, supportive ethos, and career structure needed to make the model work are described. Moral and workforce theory are used to justify why the model may be more effective for population health, delivering greater job satisfaction for individuals and ultimately helping systematically realize healthcare values. Finally, the paper sketches the first steps needed to implement the model at the national level, starting with the operationalization of new multi-'pillar' professional curricula across the career spectrum. Potential challenges also are discussed.

Are UK pharmacists ready for consultant-level practice? A cross-sectional survey of self-assessed development needs.

OBJECTIVES: The four nations of the United Kingdom (UK) have endorsed a new curriculum and credentialing process for consultant pharmacists. This study aimed to measure the self-reported consultant-level practice development needs of pharmacists across the UK. METHODS: The study was a cross-sectional electronic survey. Inclusion criteria were: pharmacists registered to practice with the General Pharmaceutical Council; working in any professional sector across the UK; and self-identifying as already working at an advanced level of practice or in an advanced pharmacist role. Participants were asked to rate their confidence that their current practice aligns to the level described in the Royal Pharmaceutical Society Consultant Pharmacist curriculum on a 5-point Likert scale. Predictors of overall confidence with the whole curriculum were analysed using binomial regression. KEY FINDINGS: Nine hundred and forty-four pharmacists participated. Median age was 42 years; 72.6% were female. Research skills and strategic leadership skills had low self-reported confidence. Patient-Centred Care and Collaboration was the domain with the highest reported confidence. 10.2% (96/944) of participants self-reported confidence across the whole curriculum. The strongest predictors of overall confidence across the curriculum were advanced clinical practitioner qualification, research qualifications and self-identifying as a specialist. Increasing age and male gender also predicted confidence. White ethnicity and having an independent prescribing qualification negatively predicted confidence. CONCLUSION: A small minority of pharmacists self-reported confidence across the whole curriculum. A planned approach to develop research skills across the career spectrum, coupled with better identification of workplace-based experiential strategic leadership opportunities, may help deliver a larger cohort of 'consultant-ready' pharmacists.

Safe co-administration of direct-acting antivirals and direct oral anticoagulants among patients with hepatitis C virus infection: An international multicenter retrospective cohort study.

Treatment for hepatitis C virus (HCV) with direct-acting antivirals (DAA) is advantageous over previous treatment options due to high efficacy, short treatment duration, and relatively few drug interactions. Similarly, direct oral anticoagulants (DOAC) are generally preferred over warfarin for the management of thrombosis and atrial fibrillation due to a favourable safety profile. Direct-acting antivirals inhibit DOAC transport through P-glycoprotein inhibition leading to a theoretical increase in bleeding risk. We evaluated the incidence of bleeding in patients who received concurrent DAA and DOAC therapy and stratified the analysis based on the patient's cirrhosis status. We conducted a multicenter, retrospective cohort study to evaluate bleeding in patients with HCV and cirrhosis compared to patients with HCV without cirrhosis. Patients receiving at least 1 month of overlapping DAA and DOAC therapy between May 2017 and August 2020 at 11 medical centers in the United Kingdom and three medical centers in the United States were included. Charts were manually reviewed to identify baseline characteristics as well as thromboembolic or bleeding events. Bleeding events were categorized as major bleeding (MB) and clinically relevant non-major bleeding (CRNMB). Of 204 total patients, 36 patients (18%) had cirrhosis and 168 patients (82%) did not have cirrhosis. The majority of patients were male (79%) and Caucasian (75%). Sofosbuvir/velpatasvir (32%) and rivaroxaban (57%) were the most commonly prescribed DAA and DOAC, respectively. Leading indications for anticoagulation included thrombosis (75%) and atrial fibrillation (21%). There were three MB events (1.5%) all of which occurred in patients with additional risk factors (age over 65 and on antiplatelet therapy) and no CRNMB occurred while on DOAC and DAA therapy. Of the three MB, one occurred in a patient with cirrhosis and two in patients without cirrhosis, RR 1.23 (0.56-2.76). In conclusion, in this multicenter cohort study of concurrent DAA and DOAC use, MB was uncommon and there was no CRNMB. There was no significant difference in bleeding events among patients with cirrhosis compared to those without cirrhosis. These findings support the use of DAA among patients requiring DOAC.

Recommendations for the Management of Drug-Drug Interactions Between the COVID-19 Antiviral Nirmatrelvir/Ritonavir (Paxlovid) and Comedications.

The coronavirus disease 2019 (COVID-19) antiviral nirmatrelvir/ritonavir (Paxlovid) has been granted authorization or approval in several countries for the treatment of patients with mild to moderate COVID-19 at high risk of progression to severe disease and with no requirement for supplemental oxygen. Nirmatrelvir/ritonavir will be primarily administered outside the hospital setting as a 5-day course oral treatment. The ritonavir component boosts plasma concentrations of nirmatrelvir through the potent and rapid inhibition of the key drug-metabolizing enzyme cytochrome P450 (CYP) 3A4. Thus nirmatrelvir/ritonavir, even given as a short treatment course, has a high potential to cause harm from drug-drug interactions (DDIs) with other drugs metabolized through this pathway. Options for mitigating risk from DDIs with nirmatrelvir/ritonavir are limited due to the clinical illness, the short window for intervention, and the related difficulty of implementing clinical monitoring or dosage adjustment of the comedication. Pragmatic options are largely confined to preemptive or symptom-driven pausing of the comedication or managing any additional risk through counseling. This review summarizes the effects of ritonavir on drug disposition (i.e., metabolizing enzymes and transporters) and discusses factors determining the likelihood of having a clinically significant DDI. Furthermore, it provides a comprehensive list of comedications likely to be used in COVID-19 patients which are categorized according to their potential DDI risk with nirmatrelvir/ritonavir. It also discusses recommendations for the management of DDIs which balance the risk of harm from DDIs with a short course of ritonavir, against unnecessary denial of nirmatrelvir/ritonavir treatment.

Real-World Outcomes in Historically Underserved Patients with Chronic Hepatitis C Infection Treated with Glecaprevir/Pibrentasvir.

INTRODUCTION: Glecaprevir/pibrentasvir is approved for treating chronic hepatitis C virus (HCV) genotypes (GT) 1-6. We evaluated real-world effectiveness, safety, and patient-reported outcomes of glecaprevir/pibrentasvir in underserved patient populations, focusing on persons who use drugs infected with HCV. METHODS: Data were pooled from nine countries (13 November 2017-31 January 2020). Patients had HCV GT1-6, with or without compensated cirrhosis, with or without prior HCV treatment and received glecaprevir/pibrentasvir consistent with local label at their physician's discretion. Patients with prior direct-acting antiviral exposure were excluded from efficacy and quality-of-life analyses. The percentage of patients achieving sustained virologic response at post-treatment week 12 (SVR12) was assessed. Mean changes from baseline to SVR12 visit in 36-Item Short-Form Health Survey mental and physical component summary scores were reported. Safety was assessed in patients receiving at least one dose of glecaprevir/pibrentasvir. RESULTS: Of 2036 patients, 1701 (83.5%) received 8-week glecaprevir/pibrentasvir. In 1684 patients with sufficient follow-up, SVR12 rates were 98.0% (1651/1684) overall, 98.1% (1432/1459) in 8-week treated patients, 97.0% (519/535) in persons who use drugs, and greater than 95% across subgroups. Mean changes from baseline in mental and physical component summary scores were 3.7 and 2.4, respectively. One glecaprevir/pibrentasvir-related serious adverse event was reported; six glecaprevir/pibrentasvir-related adverse events led to discontinuation. CONCLUSIONS: Glecaprevir/pibrentasvir was highly effective, well tolerated, and improved quality of life in HCV-infected persons who use drugs and other underserved patients. TRIAL REGISTRATION: These multinational post-marketing observational studies are registered with ClinicalTrials.gov, number NCT03303599.

Recommendations for Dosing of Repurposed COVID-19 Medications in Patients with Renal and Hepatic Impairment.

INTRODUCTION: In December 2019, an outbreak of a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) began, resulting in a number of antivirals and immune modulators being repurposed to treat the associated coronavirus disease 2019 (COVID-19). Many patients requiring treatment for COVID-19 may have either pre-existing renal or hepatic disease or experience acute renal/hepatic injury as a result of the acute infection. Altered renal or hepatic function can significantly affect drug concentrations of medications due to impaired drug metabolism and excretion, resulting in toxicity or reduced efficacy. The aim of this paper is to review the pharmacokinetics and available study data for the experimental COVID-19 therapies in patients with any degree of renal or hepatic impairment to make recommendations for dosing. METHODS: COVID-19 agents included in these recommendations were listed as primaries on the University of Liverpool COVID-19 drug interaction website ( www.covid19-druginteractions.org ), initially identified from Clinicialtrials.gov and ChicCTR.org.cn. A literature search was performed using PubMed and EMBASE as well as product licences and pharmacokinetic databases. FINDINGS: Remdesivir, dexamethasone, azithromycin, favipiravir, lopinavir/ritonavir, atazanavir, hydroxychloroquine, interferon beta, ribavirin, tocilizumab, anakinra and sarilumab were identified as experimental drugs being used in COVID-19 trials as of November 2020. Limited study data was found for these drugs in patients with renal or hepatic impairment for COVID-19 or other indications. Recommendations were made based on available data, consideration of pharmacokinetic properties (including variability), the dosing and anticipated treatment duration of each regimen in COVID-19 and known toxicities. CONCLUSION: Dosing of drugs used to treat COVID-19 in patients with renal or hepatic impairment is complex. These recommendations were produced to provide guidance to clinicians worldwide who are treating patients with COVID-19, many of whom will have some degree of acute or chronic renal or hepatic impairment.

Correction to: Real-World Clinical Practice Use of 8-Week Glecaprevir/Pibrentasvir in Treatment-Naïve Patients with Compensated Cirrhosis.

In the original article, there is an error in Fig. 1.

Real-World Clinical Practice Use of 8-Week Glecaprevir/Pibrentasvir in Treatment-Naïve Patients with Compensated Cirrhosis.

INTRODUCTION: More than 70 million people are estimated to be infected with hepatitis C virus globally. Glecaprevir/pibrentasvir is a widely used treatment and has recently been approved for an 8-week regimen for treatment-naïve patients with compensated cirrhosis in Europe and the USA, who would previously have received glecaprevir/pibrentasvir for 12 weeks. This label update was based on the EXPEDITION-8 study, which included 343 treatment-naïve patients with compensated cirrhosis. However, there is currently a lack of similarly large-scale real-world studies of the 8-week glecaprevir/pibrentasvir regimen in this population. METHODS: This summary of seven separate smaller real-world studies aims to validate the results seen in EXPEDITION-8 and provide an up-to-date real-world reference for clinicians making treatment decisions for patients with compensated cirrhosis (Child-Pugh A) who may benefit from a shorter-duration therapy with glecaprevir/pibrentasvir. The newly emerging real-world effectiveness data on treatment-naïve patients with compensated cirrhosis treated with 8 weeks of glecaprevir/pibrentasvir help to understand where further research is needed to support patients with hepatitis C virus. RESULTS: Across all seven studies, glecaprevir/pibrentasvir showed high effectiveness with an average sustained virologic response rate of 98.1%, similar to that found in a clinical trial setting (99.7%). Only one patient (0.5%) experienced virologic failure and treatment was well tolerated. CONCLUSION: Expanding the number of patients eligible for the shortened treatment duration will potentially increase treatment initiation and completion, particularly in underserved populations, contributing to the elimination of hepatitis C virus.

Drug interactions: a review of the unseen danger of experimental COVID-19 therapies.

As global health services respond to the coronavirus pandemic, many prescribers are turning to experimental drugs. This review aims to assess the risk of drug-drug interactions in the severely ill COVID-19 patient. Experimental therapies were identified by searching ClinicalTrials.gov for 'COVID-19', '2019-nCoV', '2019 novel coronavirus' and 'SARS-CoV-2'. The last search was performed on 30 June 2020. Herbal medicines, blood-derived products and in vitro studies were excluded. We identified comorbidities by searching PubMed for the MeSH terms 'COVID-19', 'Comorbidity' and 'Epidemiological Factors'. Potential drug-drug interactions were evaluated according to known pharmacokinetics, overlapping toxicities and QT risk. Drug-drug interactions were graded GREEN and YELLOW: no clinically significant interaction; AMBER: caution; RED: serious risk. A total of 2378 records were retrieved from ClinicalTrials.gov, which yielded 249 drugs that met inclusion criteria. Thirteen primary compounds were screened against 512 comedications. A full database of these interactions is available at www.covid19-druginteractions.org. Experimental therapies for COVID-19 present a risk of drug-drug interactions, with lopinavir/ritonavir (10% RED, 41% AMBER; mainly a perpetrator of pharmacokinetic interactions but also risk of QT prolongation particularly when given with concomitant drugs that can prolong QT), chloroquine and hydroxychloroquine (both 7% RED and 27% AMBER, victims of some interactions due to metabolic profile but also perpetrators of QT prolongation) posing the greatest risk. With management, these risks can be mitigated. We have published a drug-drug interaction resource to facilitate medication review for the critically ill patient.

Frequency of Potential Drug-Drug Interactions in the Changing Field of HCV Therapy.

BACKGROUND: With the introduction of direct-acting antivirals (DAAs) for hepatitis C virus (HCV) infection, drug-drug interactions (DDIs) emerged as significant challenge. Since then, HCV therapy and the infected population have rapidly changed. So far, very limited data are available regarding the clinical relevance of DDIs when using most modern DAA regimens. We aimed to assess how the importance of DDIs has evolved over time. METHODS: From January 2014 to July 2018, 668 consecutive HCV patients were evaluated for their outpatient medication and assessed for DDIs with DAAs. Different time periods were defined based on market approval of key DAAs: A (01/2014-11/2014), B (11/2014-08/2016), and C (08/2016-07/2018). RESULTS: The frequency of patients with real-world DDIs was highest in period B (A: 37.1%, B: 49.6%, C: 38.8%). The recently approved DAAs (period C) theoretically showed a lower DDI risk profile. However, real-world DDIs were still comparable to period A, as HCV patients' characteristics changed (eg, age ≥75 years: A: 3.1%, B: 9.8%, C: 5.6%; polypharmacy/patients with ≥8 drugs: A: 11.1%, B: 15.2%, C: 17.2%). Furthermore, although DDIs via CYP 3A4 became less important for some modern regimens, other mechanisms like an altered pH value in the stomach, causing reduced bioavailability, evolved. Relevant DDIs most frequently occurred with proton pump inhibitors, metamizole, statins, and carvedilol. CONCLUSIONS: DDIs during antiviral treatment still affect about 40% of HCV patients. The lower DDI potential of modern DAA regimens is partly counteracted by changing patient characteristics. Therefore, DDIs should not be underestimated.

Eight weeks of sofosbuvir/velpatasvir for genotype 3 hepatitis C in previously untreated patients with significant (F2/3) fibrosis.

Twelve weeks sofosbuvir/velpatasvir (SOF/VEL) is a highly effective pan-genotypic regimen for hepatitis C. Phase 2 data suggest 8 weeks of treatment may be sufficient for previously untreated noncirrhotic patients with genotype 3 (GT3) infection. To maximize the number of patients potentially cured within a fixed treatment budget, we elected to treat such patients locally eligible for treatment (F2/3), with 8 weeks of SOF/VEL. By local protocol, treatment-naive patients with F2 (LSM > 6.9kPa < 9.5kPa) or F3 fibrosis (≥9.5kPa < 12.5kPa) were eligible for 8-week SOF/VEL treatment. Patients commencing treatment before 1 Oct 2017 were identified from the Scottish HCV database. Baseline and treatment outcome data obtained. Ninety patients were included for analysis (72 (80%) male, mean age 45 (IQR ± 8.4), 28 (31.1%) F3 fibrosis). Opioid agonist therapy (OAT) was prescribed in 82 (91.1%) patients. Of 49 patients attending Glasgow city Alcohol and Drug Services, 27 (55.1%) had evidence of recent drug use (< 3 months) including 8 (16.3%) with self-reported intravenous drug use. On an intention-to-treat basis, SVR rates were 86/90 (95.6%, 95% CI 89.0-98.8). Excluding those who prematurely discontinued treatment (n = 4), died prior to SVR testing (n = 1) or whom experienced reinfection (n = 1), per-protocol SVR rate was 84/84 (100%, 95% CI 95.7-100.0). In conclusion, eight-week SOF/VEL is highly effective in treatment-naive GT3 patients with significant fibrosis. This offers a non-protease inhibitor-based 8-week regimen which may be useful for complex drug interactions or where time-limited opportunity for treatment. In limited resource settings, reduction in drug acquisition costs may help achieve progress towards the goal of HCV elimination.

Efficacy and safety of glecaprevir/pibrentasvir in patients with chronic HCV infection and psychiatric disorders: An integrated analysis.

Although direct-acting antivirals (DAAs) for chronic hepatitis C virus (HCV) infection are highly efficacious and safe, treatment initiation is often limited in patients with neuropsychiatric disorders due to concerns over reduced treatment adherence and drug-drug interactions. Here, we report adherence, efficacy, safety and patient-reported outcomes (PROs) from an integrated analysis of registrational studies using the pangenotypic DAA regimen of glecaprevir and pibrentasvir (G/P). Patients with chronic HCV genotypes 1-6 infection with compensated liver disease (with or without cirrhosis) receiving G/P for 8, 12 or 16 weeks were included in this analysis. Patients were classified as having a psychiatric disorder based on medical history and/or co-medications. Primary analyses assessed treatment adherence, efficacy (sustained virologic response at post-treatment week 12; SVR12), safety and PROs. Among 2522 patients receiving G/P, 789 (31%) had a psychiatric disorder with the most common diagnoses being depression (64%; 506/789) and anxiety disorders (27%; 216/789). Treatment adherence was comparably high (>95%) in patients with and without psychiatric disorders. SVR12 rates were 97.3% (768/789; 95% CI = 96.2-98.5) and 97.5% (1689/1733; 95% CI = 96.7-98.2) in patients with and without psychiatric disorders, respectively. Among patients with psychiatric disorders, SVR12 rates remained >96% by individual psychiatric diagnoses and co-medication classes. Overall, most adverse events (AEs) were mild-to-moderate in severity with serious AEs and AEs leading to G/P discontinuation occurring at similarly low rates in both patient populations. In conclusion, G/P treatment was highly efficacious, well-tolerated and demonstrated high adherence rates in patients with chronic HCV infection and psychiatric disorders.

Real-world safety and effectiveness of ombitasvir/paritaprevir/ritonavir ± dasabuvir ± ribavirin in hepatitis C virus genotype 1- and 4-infected patients with diverse comorbidities and comedications: A pooled analysis of post-marketing observational studies from 13 countries.

Ombitasvir/paritaprevir/ritonavir ± dasabuvir ± ribavirin (OBV/PTV/r ± DSV ± RBV) regimens show high efficacy and good tolerability in clinical trials for chronic hepatitis C virus (HCV) genotypes (GT) 1 or 4. To evaluate whether these results translate to clinical practice, data were pooled from observational studies across 13 countries. Treatment-naïve or -experienced patients, with or without cirrhosis, received OBV/PTV/r ± DSV ± RBV according to approved local labels and clinical practice. Sustained virologic response at post-treatment Week 12 (SVR12), adverse events (AEs) and comedication management were assessed for patients initiating treatment before 1 June 2017. The safety population included 3850 patients who received ≥1 dose of study drug. The core population (N = 3808) further excluded patients with unknown GT or cirrhosis status, or who received off-label treatment. Patients had HCV GT1a (n = 732; 19%), GT1b (n = 2619; 69%) or GT4 (n = 457; 12%). In 3546 patients with sufficient follow-up data at post-treatment Week 12, the SVR12 rate was 96% (n/N = 3401/3546 [95% CI 95.2-96.5]). In patients with or without cirrhosis, SVR12 was comparable (96%). In patients with HCV GT1a, GT1b or GT4, SVR12 rates were 93%, 97% and 94%. In GT1b-infected patients with planned treatment for 8 weeks, SVR12 was 96%. In patients with ≥1 comorbidity (67%), SVR12 was 95%. 58% of patients received ≥1 comedication, and there was minimal impact on SVR12 rates using comedications for peptic ulcers and gastro-esophageal reflux disease, statins, antipsychotics or antiepileptics. Most comedications were maintained during treatment although 58% of patients changed their statin medication. AEs and serious AEs occurred in 26% and 3% of patients. Post-baseline Grade 3-4 laboratory abnormalities were rare (<3%), and discontinuation rates were low (<4%). Real-world evidence confirms the effectiveness of OBV/PTV/r ± DSV ± RBV in patients with HCV GT1 or GT4, regardless of common comorbidities or comedications, and is consistent with clinical trial results. Adverse safety outcomes may be limited by underreporting in the real-world setting.

Clinical impact of pharmacokinetic interactions between the HCV protease inhibitor simeprevir and frequently used concomitant medications.

AIMS: Direct-acting antiviral agents (DAAs) for the treatment of hepatitis C (HCV) can be associated with drug-drug interactions (DDIs) with concomitant medications. The practical clinical implications of such DDIs are poorly understood. We assessed the clinical impact of possible pharmacokinetic (PK) interactions between simeprevir and frequently prescribed concomitant medications. METHODS: This post hoc analysis pooled data from nine studies which evaluated simeprevir (SMV)-based interferon-free HCV treatment. Three classes of frequently used concomitant medications of interest (CMOIs) were analysed [antihypertensive drugs (AHDs), anxiolytic drugs (AXDs) and lipid-lowering drugs (LLDs)] and categorized as amber or green according to their DDI potential with SMV (green: no DDIs; amber: potential/known PK interactions). Concomitant medications not recommended to be coadministered with SMV were not included. The composite primary endpoint was defined as the frequency of either discontinuation, interruption or dose modification of the CMOI during 12 weeks of SMV treatment. RESULTS: Few patients met the composite endpoint in the various subgroups. Patients on amber CMOIs tended to experience CMOI modification more often (13.4-19.4%) than those on green CMOIs (3.1-10.8%). There was no difference in the frequency of adverse events between patients taking green and those taking amber CMOIs. CONCLUSIONS: In this large pooled analysis, coadministration of the evaluated commonly prescribed medications with known or potential PK interactions with SMV was manageable and resulted in few adjustments of concomitant medications. Our method could serve as a blueprint for the evaluation of the impact of DDIs.