Drug-Disease Interactions: Losartan Effect Is Not Downregulated by Rheumatoid Arthritis

Drug-disease interaction: Clinical consequences of inflammation on drugs action and disposition

Inflammation is a culprit in many conditions affecting millions of people worldwide. A plethora of studies has revealed that inflammation and inflammatory mediators such as cytokines and chemokines are associated with altered expression and activity of various proteins such as those involved in drug metabolism, specifically cytochrome P450 enzymes (CYPs). Emphasis of most available reports is on the inflammation-induced downregulation of CYPs, subsequently an increase in their substrate concentrations, and the link between the condition and the inflammatory mediators such as interleukin-6 and tumor necrosis factor alpha. However, reports also suggest that inflammation influences expression and/or activity of other proteins such as those involved in the drug-receptor interaction. These multifaced involvements render the clinical consequence of the inflammation unexpected. Such changes are shown in many inflammatory conditions including rheumatoid arthritis, Crohn's disease, acute respiratory illnesses as well as natural processes such as aging, among others. For example, some commonly used cardiovascular drugs lose their efficacy when patients get afflicted with inflammatory conditions such as rheumatoid arthritis and Crohn's disease. Interestingly, this is despite increased concentration subsequent to reduced clearance. The observation is attributed to a simultaneous reduction in the expression of target receptor proteins such as the calcium and potassium channel and β-adrenergic receptor as well as the metabolic enzymes. This narrative review summarizes the current understanding and clinical implications of the inflammatory effects on both CYPs and drug-receptor target proteins.

Influence of Inflammation on Cytochromes P450 Activity in Adults: A Systematic Review of the Literature

Background: Available in-vitro and animal studies indicate that inflammation impacts cytochromes P450 (CYP) activity via multiple and complex transcriptional and post-transcriptional mechanisms, depending on the specific CYP isoforms and the nature of inflammation mediators. It is essential to review the current published data on the impact of inflammation on CYP activities in adults to support drug individualization based on comorbidities and diseases in clinical practice. Methods: This systematic review was conducted in PubMed through 7th January 2021 looking for articles that investigated the consequences of inflammation on CYP activities in adults. Information on the source of inflammation, victim drugs (and CYPs involved), effect of disease-drug interaction, number of subjects, and study design were extracted. Results: The search strategy identified 218 studies and case reports that met our inclusion criteria. These articles were divided into fourteen different sources of inflammation (such as infection, autoimmune diseases, cancer, therapies with immunomodulator…). The impact of inflammation on CYP activities appeared to be isoform-specific and dependent on the nature and severity of the underlying disease causing the inflammation. Some of these drug-disease interactions had a significant influence on drug pharmacokinetic parameters and on clinical management. For example, clozapine levels doubled with signs of toxicity during infections and the concentration ratio between clopidogrel's active metabolite and clopidogrel is 48-fold lower in critically ill patients. Infection and CYP3A were the most cited perpetrator of inflammation and the most studied CYP, respectively. Moreover, some data suggest that resolution of inflammation results in a return to baseline CYP activities. Conclusion: Convincing evidence shows that inflammation is a major factor to be taken into account in drug development and in clinical practice to avoid any efficacy or safety issues because inflammation modulates CYP activities and thus drug pharmacokinetics. The impact is different depending on the CYP isoform and the inflammatory disease considered. Moreover, resolution of inflammation appears to result in a normalization of CYP activity. However, some results are still equivocal and further investigations are thus needed.

Clinical and Molecular Perspectives on Inflammation-Mediated Regulation of Drug Metabolism and Transport

Inflammation is a possible cause of variability in drug response and toxicity due to altered regulation in drug-metabolizing enzymes and transporters (DMETs) in humans. Here, we evaluate the clinical and in vitro evidence on inflammation-mediated modulation of DMETs, and the impact on drug metabolism in humans. Furthermore, we identify and discuss the gaps in our current knowledge. A systematic literature search on PubMed, Embase, and grey literature was performed in the period of February to September 2020. A total of 203 papers was included. In vitro studies in primary human hepatocytes revealed strong evidence that CYP3A4 is strongly downregulated by inflammatory cytokines IL-6 and IL-1β. CYP1A2, CYP2C9, CYP2C19, and CYP2D6 were downregulated to a lesser extent. In clinical studies, acute and chronic inflammatory diseases were observed to cause downregulation of CYP enzymes in a similar pattern. However, there is no clear correlation between in vitro studies and clinical studies, mainly because most in vitro studies use supraphysiological cytokine doses. Moreover, clinical studies demonstrate considerable variability in terms of methodology and inconsistencies in evaluation of the inflammatory state. In conclusion, we find inflammation and pro-inflammatory cytokines to be important factors in regulation of drug-metabolizing enzymes and transporters. The observed downregulation is clinically relevant, and we emphasize caution when treating patients in an inflammatory state with narrow therapeutic index drugs. Further research is needed to identify the full extent of inflammation-mediated changes in DMETs and to further support personalized medicine.

Effect of interleukin-6, -17, -21, -22, and -23 and STAT3 on signal transduction pathways and their inhibition in autoimmune arthritis

Rheumatic diseases are complex autoimmune diseases which include among others rheumatoid arthritis (RA), juvenile idiopathic arthritis (JIA), and psoriatic arthritis (PsA). These diseases are characterized by prolonged and increased secretion of inflammatory factors, eventually leading to inflammation. This is often accompanied by persistent pain and stiffness in the joint and finally bone destruction and osteoporosis. These diseases can occur at any age, regardless of gender or origin. Autoimmune arthritis is admittedly associated with long-term treatment, and discontinuation of medication is associated with unavoidable relapse. Therefore, it is important to detect the disease at an early stage and apply appropriate preventative measures. During inflammation, pro-inflammatory factors such as interleukins (IL)-6, -17, -21, -22, and -23 are secreted, while anti-inflammatory factors including IL-10 are downregulated. Research conducted over the past several years has focused on inhibiting inflammatory pathways and activating anti-inflammatory factors to improve the quality of life of people with rheumatic diseases. The aim of this paper is to review current knowledge on stimulatory and inhibitory pathways involving the signal transducer and activator of transcription 3 (STAT3). STAT3 has been shown to be one of the crucial factors involved in inflammation and is directly linked with other pro-inflammatory factors and thus is a target of current research on rheumatoid diseases.

Pharmacological management of cardiovascular risk in chronic inflammatory rheumatic diseases

INTRODUCTION

Cardiovascular comorbidity is a major burden in patients with chronic inflammatory rheumatic diseases and a significant determinant of their outcome. In addition to optimal management of the underlying inflammatory condition according to current guidelines, individual cardiovascular risk factors, particularly dyslipidaemia, hypertension, and impaired glucose tolerance should be assessed regularly and guide risk stratification and requirement for treatment.

AREAS DISCUSSED

We critically reviewed manuscripts and guidelines on the pharmacological management of dyslipidaemia, hypertension, and diabetes in patients with chronic inflammatory rheumatic diseases (PubMed, MEDLINE, EMBASE, Scopus, Web of Science and Google Scholar, up to 1 March 2020). Lifestyle changes are of paramount importance for the management of these risk factors. In the current narrative review, we discuss pharmacological therapies available and emerging therapies aiming to help patients achieve recommended targets, depending on their individual risk.

EXPERT OPINION

CVD risk is increased in people with chronic inflammatory rheumatic diseases. Cardiovascular risk factor management is an essential part of their care. Although relevant guidance exists, there are still major gaps in knowledge and risk factor management implementation in these patient groups. Some practical guidance based on our interpretation of existing data and experience in the field is provided in this review.

Lower CYP2C9 activity in Turkish patients with Behçet's disease compared to healthy subjects: a down-regulation due to inflammation?

BACKGROUND

We previously reported on a Swedish patient with Behçet's disease (BD) who was an ultra-rapid metaboliser of drugs catalysed by CYP2C9. Was this extreme metabolism caused by the disease?

AIM

This study aims to compare the genotype/phenotype of CYP2C9 in patients with BD and healthy subjects. As the occurrence of BD is high in Turkey, all subjects were recruited from this country.

METHODS

Genotyping of CYP2C9 was performed using standard PCR-RFLP and allele-specific PCR methods. Phenotyping of CYP2C9 was performed by administration of a 50-mg single oral dose of losartan and by calculating the urinary metabolic ratio (MR) of probe drug to its metabolite E-3174. Quantitation was performed by HPLC.

RESULTS

The frequency of CYP2C9*2 and *3 was not significantly different between the Behçet's disease patients (12.5 and 8.7%) and the healthy subjects (8.9 and 8.2%). The geometric mean losartan MR was higher in the 52 patients (1.75) than in the 96 healthy subjects (1.02) (p = 0.002; t-test). Within the genotypes *1/*1, there was a significant difference of MR between patients and healthy subjects (P = 0.006). All but three of the Behçet's disease patients were treated with colchicine. In nine subsequent patients, we found no significant effect of 2 weeks of treatment with colchicine on the CYP2C9 MR.

CONCLUSION

Contrary to expectation, the CYP2C9 activity was lower in Turkish BD patients compared to healthy subjects. As this seems not to be due to colchicine treatment, our hypothesis is that inflammation related to BD might have caused the down-regulation of the CYP2C9 activity due to immune cytokine reactions. The ultra-rapid metabolism of CYP2C9 substrate drugs in the Swedish patient was not due to her BD.

Adherence to cardiovascular prevention strategies in patients with rheumatoid arthritis

OBJECTIVES

Patients with rheumatoid arthritis (RA) have a high risk of cardiovascular disease (CVD). Recent national and international guidelines suggest strict treatment of CVD risk factors in RA. The aim of this study was to evaluate the self-reported adherence to CV prevention strategies in patients with RA.

METHOD

RA patients visiting an outpatient clinic for strict CVD risk management received a validated questionnaire to evaluate adherence to CV prevention strategies. Strict treatment targets were defined and lifestyle recommendations were given following a prespecified protocol. CVD risk was assessed using the SCORE algorithm.

RESULTS

In total, 111 questionnaires were returned (response rate of 82%). A high 10-year CVD risk (≥ 20%) was present in 53%, but only 3% thought they had an increased CVD risk. A total of 53% of patients reported that they 'follow the doctors' suggestions exactly' and 75% reported finding it 'easy to follow the suggestions'. Of the 69% of patients who were prescribed lipid- and/or blood pressure-lowering drugs, 90% reported taking all prescribed tablets. The advice to follow a diet was given to 42%, of whom 68% said they followed the advised diet. Physical exercise was advised to 67%, of whom 62% said they performed specific physical exercise on at least 3 days a week. The adherence to lifestyle recommendations was not significantly different across the CVD risk groups.

CONCLUSIONS

RA patients tend to underestimate their CVD risk. The self-reported adherence of RA patients to CVD risk management was high concerning pharmaceutical interventions and moderate in the case of lifestyle interventions.

Inflammation-induced phenoconversion of polymorphic drug metabolizing enzymes: hypothesis with implications for personalized medicine

Phenoconversion transiently converts genotypic extensive metabolizers (EMs) into phenotypic poor metabolizers (PMs) of drugs, potentially with corresponding changes in clinical response. This phenomenon, typically resulting from coadministration of medications that inhibit certain drug metabolizing enzymes (DMEs), is especially well documented for enzymes of the cytochrome P450 family. Nonclinical evidence gathered over the last two decades also strongly implicates elevated levels of some proinflammatory cytokines, released during inflammation, in down-regulation of drug metabolism, especially by certain DMEs of the P450 family, thereby potentially causing transient phenoconversion. Clinically, phenoconversion of NAT2, CYP2C19, and CYP2D6 has been documented in inflammatory conditions associated with elevated cytokines, such as human immunodeficiency virus infection, cancer, and liver disease. The potential of other inflammatory conditions to cause phenoconversion has not been studied but experimental and anecdotal clinical evidence supports infection-induced down-regulation of CYP1A2, CYP3A4, and CYP2C9 as well. Collectively, the evidence supports a hypothesis that certain inflammatory conditions associated with elevated proinflammatory cytokines may cause phenoconversion of certain DMEs. Since inflammatory conditions associated with elevated levels of proinflammatory cytokines are highly prevalent, phenoconversion of genotypic EM patients into transient phenotypic PMs may be more frequent than appreciated. Since drug pharmacokinetics, and therefore the clinical response, is influenced by DME phenotype rather than genotype per se, phenoconversion (whatever its cause) can have a significant impact on the analysis and interpretation of genotype-focused clinical outcome association studies. There is a risk that focusing on genotype alone may miss important associations between clinical outcomes and DME phenotypes, thus compromising future prospects of personalized medicine.

Drug-disease interaction: Crohn's disease elevates verapamil plasma concentrations but reduces response to the drug proportional to disease activity

AIM

Inflammation is involved in the pathogenesis of cardiovascular diseases that includes reduced response to pharmacotherapy due to altered pharmacokinetics and pharmacodynamics. It is not known if these effects exist in general in all inflammatory conditions. It also remains unknown whether in a given population the effect is a function of disease severity. We investigated whether pharmacokinetics and pharmacodynamics of a typical calcium channel inhibitor are influenced by Crohn's disease (CD), a disease for which the disease severity can be readily ranked.

METHODS

We administered 80 mg verapamil orally to (i) healthy control subjects (n= 9), (ii) patients with clinically quiescent CD (n= 22) and (iii) patients with clinically active CD (n= 14). Serial analysis of verapamil enantiomers (total and plasma unbound), blood pressure and electrocardiograms were recorded over 8 h post dose. The severity of CD was measured using the Harvey-Bradshaw Index.

RESULTS

CD substantially and significantly increased plasma verapamil concentration and in a stereoselective fashion (S, 9-fold; R, 2-fold). The elevated verapamil concentration, however, failed to result in an increased verapamil pharmacodynamic effect so that the patients with elevated verapamil concentration demonstrated no significant increase in response measured as PR interval and blood pressure. Instead, the greater the disease severity, the lower was the drug potency to prolong PR interval (r= 0.86, P < 0.0006),

CONCLUSIONS

CD patients with severe disease may not respond to cardiovascular therapy with calcium channel blockers. Reducing the severity increases response despite reduced drug concentration. This observation may have therapeutic implication beyond the disease and the drug studies herein.

Effect of obesity on response to cardiovascular drugs in pediatric patients with renal disease

Obesity is associated with an increased concentration of inflammatory mediators, which in turn, in adults, reduces the response to calcium channel blockers (CCBs). We reviewed the medical charts of 263 pediatric nephrology patients with renal conditions, with the aim of studying the effect of obesity on the response to L-type CCBs, angiotensin interrupting agents (ANGIs), or a combination of the two. Forty-eight patients were ultimately enrolled in the study: 25 obese and 23 non-obese patients. The effect of the treatments on lowering the blood pressure was compared in obese versus non-obese patients. The systolic response to CCBs, measured as at least a 10% reduction from the baseline, was significantly lower in the obese (12.5%) patients than in the non-obese (52.9%) ones. The differences in diastolic response (58.8 and 25% for non-obese and obese patients, respectively) did not reach significance. The percentage response to CCBs, however, was significantly less in the obese patients than in the non-obese patients for both systolic and diastolic blood pressure. Corticosteroids also significantly influenced the response to CCBs in terms of diastolic pressure (62.9 and 25% for non-obese and obese patients, respectively). None of the tested covariates, including obesity, was found to significantly influence the response to ANGIs alone or in various combinations with CCBs. In conclusion, obesity and corticosteroid therapy should be considered when initiating antihypertensive drug treatment in children with kidney disease as both may contribute to a reduced efficacy of the antihypertensive therapy.

Influence of controlled rheumatoid arthritis on the action and disposition of verapamil: focus on infliximab

Active rheumatoid arthritis (RA), obesity, and old age are associated with reduced responsiveness to the calcium channel antagonist verapamil despite increased drug concentrations. The diminishing effect appears to be associated with the severity of inflammation. We examined pharmacodynamics and pharmacokinetics of verapamil in patients with controlled RA. Volunteers included RA patients in remission: 12 on infliximab, 8 on other antirheumatic therapy, and 12 healthy subjects. Verapamil plasma concentrations and selected inflammatory mediators as well as blood pressure and electrocardiographic parameters were recorded after a single 80-mg dose of verapamil. Inflammatory mediators were all below what is reported for active RA, confirming that RA was controlled. The tumor necrosis factor-alpha concentration, however, was significantly higher in the infliximab group compared with other groups and the literature value for active RA. No significant difference was observed between groups in terms of percentage prolongation of PR interval despite a trend toward a lower response in the RA groups, the mean plasma concentrations, and the total and unbound area under the curve of verapamil. However, the slope of the S-verapamil concentration-effect curve was steeper for controls compared with the RA patients. Remission from active disease appears to restore plasma protein levels and hepatic drug metabolism activity in patients with RA, resulting in relatively normal verapamil pharmacokinetics.

Hypertension in rheumatoid arthritis

RA associates with an increased burden of cardiovascular disease, which is at least partially attributed to classical risk factors such as hypertension (HT) and dyslipidaemia. HT is highly prevalent, and seems to be under-diagnosed and under-treated among patients with RA. In this review, we discuss the mechanisms that may lead to increased blood pressure in such patients, paying particular attention to commonly used drugs for the treatment of RA. We also suggest screening strategies and management algorithms for HT, specific to the RA population, although it is clear that these need to be formally assessed in prospective randomized controlled trials designed specifically for the purpose, which, unfortunately, are currently lacking.

Effects of angiotensin II blockade on inflammation-induced alterations of pharmacokinetics and pharmacodynamics of calcium channel blockers

BACKGROUND AND PURPOSE

Inflammation elevates plasma verapamil concentrations but diminishes pharmacological response. Angiotensin II is a pro-inflammatory mediator. We examined the effect of angiotensin II receptor blockade on the pharmacokinetics and pharmacodynamics of verapamil, as well as the binding properties and amounts of its target protein in calcium channels, in a rat model of inflammation.

EXPERIMENTAL APPROACH

We used 4 groups of male Sprague-Dawley rats (220-280 g): inflamed-placebo, inflamed-treated, control-placebo and control-treated. Inflammation as pre-adjuvant arthritis was induced by injecting Mycobacterium butyricum on day 0. From day 6 to 12, 30 mg kg(-1) oral valsartan or placebo was administered twice daily. On day 12, a single oral dose of 25 mg kg(-1) verapamil was administered and prolongation of the PR interval measured and plasma samples collected for verapamil and nor-verapamil analysis. The amounts of the target protein Ca(v)1.2 subunit of L-type calcium channels in heart was measured by Western blotting and ligand binding with (3)H-nitrendipine.

KEY RESULTS

Inflammation reduced effects of verapamil, although plasma drug concentrations were increased. This was associated with a reduction in ligand binding capacity and amount of the calcium channel target protein in heart extracts. Valsartan significantly reversed the down-regulating effect of inflammation on verapamil's effects on the PR interval, and the lower level of protein binding and the decreased target protein.

CONCLUSIONS AND IMPLICATIONS

Reduced responses to calcium channel blockers in inflammatory conditions appeared to be due to a reduced amount of target protein that was reversed by the angiotensin II antagonist, valsartan.