Cyclosporin pharmacokinetics after intravenous and oral administration in patients with Crohn's disease

Immunosuppression in solid organ-transplant recipients and impact on nutrition support

A key component to nutrition support is to consider immunosuppressive agents, the interaction with nutrients, and how the side effects of the medications influence nutrition support. The immunosuppression of the solid organ-transplant recipient involves the individualized titration of multiple therapeutic agents to prevent allorecognition and, thus, rejection of the transplanted organ. Induction immunosuppression includes the agents used at the time of transplant to prevent early rejection. Maintenance immunosuppression typically consists of oral medications taken for life. Regular therapeutic monitoring of immunosuppression is necessary to balance the risk of rejection with that of infections and malignancy. In the acute-care setting, multidisciplinary collaboration, including pharmacy and nutrition, is needed to optimize the route of administration, titration, and side effects of immunosuppression. Long-term nutrition management after transplant is also vital to prevent exacerbating adverse effects of immunosuppressive therapies, including diabetes mellitus, hypertension, dyslipidemia, obesity, and bone loss. This review summarizes common immunosuppressive agents currently utilized in solid organ-transplant recipients and factors that may influence decisions on nutrition support.

Investigating the Impact of Crohn's Disease on the Bioaccessibility of a Lipid-Based Formulation with an In Vitro Dynamic Gastrointestinal Model

The aim of the study was to investigate the impact of Crohn's disease (CD) on the performance of a lipid-based formulation of ciprofloxacin in a complex gastrointestinal simulator (TIM-1, TNO) and to compare the luminal environment in terms of bile salt and lipid composition in CD and healthy conditions. CD conditions were simulated in the TIM-1 system with a reduced concentration of porcine pancreatin and porcine bile. The bioaccessibility of ciprofloxacin was similar in simulated CD and healthy conditions considering its extent as well as its time course in the jejunum and ileum filtrate. Differences were observed in terms of the luminal concentration of triglycerides, monoglycerides, and fatty acids in the different TIM-1 compartments, indicating a reduction and delay in the lipolysis of formulation excipients in CD. The quantitative analysis of bile salts revealed higher concentrations for healthy conditions (standard TIM-1 fasted-state protocol) in the duodenum and jejunum TIM-1 compartments compared to published data in human intestinal fluids of healthy subjects. The reduced concentrations of bile salts in simulated CD conditions correspond to the levels observed in human intestinal fluids of healthy subjects in the fasted state.A lipidomics approach with ultra performance liquid chromatography (UPLC)/mass spectrometry (MS) has proven to be a time-efficient method to semiquantitatively analyze differences in fatty acid and bile salt levels between healthy and CD conditions. The dynamic luminal environment in CD and healthy conditions after administration of a lipid-based formulation can be simulated using the TIM-1 system. For ciprofloxacin, an altered luminal lipid composition had no impact on its performance indicating a low risk of altered performance in CD patients.

Clinical Pharmacokinetic and Pharmacodynamic Considerations in the Treatment of Ulcerative Colitis

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) of unknown etiology, probably caused by a combination of genetic and environmental factors. The treatment of patients with active UC depends on the severity, localization and history of IBD medication. According to the classic step-up approach, treatment with 5-aminosalicylic acid compounds is the first step in the treatment of mild to moderately active UC. Corticosteroids, such as prednisolone are used in UC patients with moderate to severe disease activity, but only for remission induction therapy because of side effects associated with long-term use. Thiopurines are the next step in the treatment of active UC but monotherapy during induction therapy in UC patients is not preferred because of their slow onset. Therapeutic drug monitoring (TDM) of the pharmacologically active metabolites of thiopurines, 6-thioguanine nucleotide (6-TGN), has proven to be beneficial. Thiopurine S-methyltransferase (TMPT) plays a role in the metabolic conversion pathway of thiopurines and exhibits genetic polymorphism; however, the clinical benefit and relevance of TPMT genotyping is not well established. In patients with severely active UC refractory to corticosteroids, calcineurin inhibitors such as ciclosporin A (CsA) and tacrolimus are potential therapeutic options. These agents usually have a rather rapid onset of action. Monoclonal antibodies (anti-tumor necrosis factor [TNF] agents, vedolizumab) are the last pharmacotherapeutic option for UC patients before surgery becomes inevitable. Body weight, albumin status and antidrug antibodies contribute to the variability in the pharmacokinetics of anti-TNF agents. Additionally, the use of concomitant immunomodulators (thiopurines/methotrexate) lowers the rate of immunogenicity, and therefore the concomitant use of anti-TNF therapy with an immunomodulator may confer some advantage compared with monotherapy in certain patients. TDM of anti-TNF agents could be beneficial in patients with primary nonresponse and secondary loss of response. The potential benefit of applying TDM during vedolizumab treatment has yet to be determined.

Clinical Pharmacokinetic and Pharmacodynamic Considerations in the Treatment of Inflammatory Bowel Disease

According to recent clinical consensus, pharmacotherapy of inflammatory bowel disease (IBD) is, or should be, personalized medicine. IBD treatment is complex, with highly different treatment classes and relatively few data on treatment strategy. Although thorough evidence-based international IBD guidelines currently exist, appropriate drug and dose choice remains challenging as many disease (disease type, location of disease, disease activity and course, extraintestinal manifestations, complications) and patient characteristics [(pharmaco-)genetic predisposition, response to previous medications, side-effect profile, necessary onset of response, convenience, concurrent therapy, adherence to (maintenance) therapy] are involved. Detailed pharmacological knowledge of the IBD drug arsenal is essential for choosing the right drug, in the right dose, in the right administration form, at the right time, for each individual patient. In this in-depth review, clinical pharmacodynamic and pharmacokinetic considerations are provided for tailoring treatment with the most common IBD drugs. Development (with consequent prospective validation) of easy-to-use treatment algorithms based on these considerations and new pharmacological data may facilitate optimal and effective IBD treatment, preferably corroborated by effectiveness and safety registries.

Review article: The pharmacokinetics and pharmacodynamics of drugs used in inflammatory bowel disease treatment

BACKGROUND

The following review is a compilation of the recent advances and knowledge on the behaviour of the most frequently used compounds to treat inflammatory bowel disease in an organism.

RESULTS

It considers clinical aspects of each entity and the pharmacokinetic/pharmacodynamic relationship supported by the use of plasma monitoring, tissue concentrations, and certain aspects derived from pharmacogenetics.

Pharmacokinetic monitoring of intravenous cyclosporine A in pediatric stem-cell transplant recipients. The trough level is not enough

In order to monitor CsA serum levels after SCT, trough levels (C0) are widely used. The aim of this study was to estimate the population and individual PK parameters for patients receiving intravenous CsA after SCT. In 27 pediatric patients after SCT receiving CsA (3 mg/kg/day) every 12 h, a total of 289 CsA concentrations was obtained. To describe the PK parameters of CsA, a two-compartment model with first order elimination was used. Covariate analysis identified body weight, age, and the co-administration with itraconazole and tobramycine as factors influencing the Cl. The statistical comparison of AUC, trough level, and C2 indicates a correlation between AUC and C2, but no correlation between the AUC and C0, r = 0.24 (p = 0.146) vs. r = 0.526 (p = 0.000692), respectively. Our results underscore the fact that CsA trough levels do not reflect the drug exposure in patients receiving intravenous CsA after SCT. By contrast, CsA blood levels measured 2-6 h after CsA infusion showed a better correlation with the AUC. Our data provide new information to optimize the balancing act between GvHD-prophylaxis, graft vs. leukemia effect, and CsA side-effects after SCT.

On the action of cyclosporine A, rapamycin and tacrolimus on M. avium including subspecies paratuberculosis

Background

Mycobacterium avium subspecies paratuberculosis (MAP) may be zoonotic. Recently the “immuno-modulators” methotrexate, azathioprine and 6-MP and the “anti-inflammatory” 5-ASA have been shown to inhibit MAP growth in vitro. We concluded that their most plausible mechanism of action is as antiMAP antibiotics. The “immunosuppressants” Cyclosporine A, Rapamycin and Tacrolimus (FK 506) treat a variety of “autoimmune” and “inflammatory” diseases. Rapamycin and Tacrolimus are macrolides. We hypothesized that their mode of action may simply be to inhibit MAP growth.

Methodology

The effect on radiometric MAP ¹⁴CO₂ growth kinetics of Cyclosporine A, Rapamycin and Tacrolimus on MAP cultured from humans (Dominic & UCF 4) or ruminants (ATCC 19698 & 303) and M. avium subspecies avium (ATCC 25291 & 101) are presented as “percent decrease in cumulative GI” (%-ΔcGI.)

Principal Findings

The positive control clofazimine has 99%-ΔcGI at 0.5 µg/ml (Dominic). Phthalimide, a negative control has no dose dependent inhibition on any strain. Against MAP there is dose dependent inhibition by the immunosuppressants. Cyclosporine has 97%-ΔcGI by 32 µg/ml (Dominic), Rapamycin has 74%-ΔcGI by 64 µg/ml (UCF 4) and Tacrolimus 43%-ΔcGI by 64 µg/ml (UCF 4)

Conclusions

We show heretofore-undescribed inhibition of MAP growth in vitro by “immunosuppressants;” the cyclic undecapeptide Cyclosporine A, and the macrolides Rapamycin and Tacrolimus. These data are compatible with our thesis that, unknowingly, the medical profession has been treating MAP infections since 1942 when 5-ASA and subsequently azathioprine, 6-MP and methotrexate were introduced in the therapy of some “autoimmune” and “inflammatory” diseases.

Cyclosporine, tacrolimus, and mycophenolate mofetil in the treatment of inflammatory bowel disease

In the past decade, immunosuppressive drugs have come to play an integral role in the treatment of patients with inflammatory bowel disease. Cyclosporine, microemulsion cyclosporine, tacrolimus, and mycophenolate mofetil can be considered for the treatment of patients with refractory inflammatory Crohn's disease, fistulizing Crohn's disease, and severe ulcerative colitis. This article reviews the use of cyclosporine, tacrolimus, and mycophenolate mofetil in patients with inflammatory bowel disease, with emphasis on pharmacology, results in controlled clinical trials, and safety, and issues related to dosing and toxicity monitoring.

Pharmacokinetic considerations in the treatment of inflammatory bowel disease

This review describes the pharmacokinetics of the major drugs used for the treatment of inflammatory bowel disease. This information can be helpful for the selection of a particular agent and offers guidance for effective and well tolerated regimens. The corticosteroids have a short elimination half-life (t1/2beta) of 1.5 to 4 hours, but their biological half-lives are much longer (12 to 36 hours). Most are moderate or high clearance drugs that are hepatically eliminated, primarily by cytochrome P450 (CYP) 3A4-mediated metabolism. Prednisone and budesonide undergo presystemic elimination. Any disease state or comedication affecting CYP3A4 activity should be taken into account when prescribing corticosteroids. Depending on the preparation used, 10 to 50% of an oral or rectal dose of mesalazine is absorbed. Rapid acetylation in the intestinal wall and liver (t1/2beta 0.5 to 2 hours) and transport probably by P-glycoprotein affect mucosal concentrations of mesalazine, which apparently determine clinical response. Any clinical condition influencing the release and topical availability of mesalazine might modify its therapeutic potential. Metronidazole has high (approximately 90%) oral bioavailability, with hepatic elimination characterised by a t1/2beta of 6 to 10 hours and a total clearance of about 4 L/h/kg. Ciprofloxacin is largely excreted unchanged both renally (about 45% of dose) and extrarenally (25%), with a relatively short t1/2beta (3.5 to 7 hours). Thus, renal function affects the systemic availability of ciprofloxacin. Both mercaptopurine and its prodrug azathioprine are metabolised to active compounds (6-thioguanine nucleotides; 6-TGN) by hypoxanthine-guanine phosphoribosyltransferase and to inactive metabolites by the polymorphically expressed thiopurine S-methyltransferase (TPMT) and xanthine oxidase. Patients with low TPMT activity have a higher risk of developing haemopoietic toxicity. Both mercaptopurine and azathioprine have a short t1/2beta (1 to 2 hours), but the t1/2beta of 6-TGN ranges from 3 to 13 days. Therapeutic response seems to be related to 6-TGN concentration. Almost complete bioavailability has been observed after intramuscular and subcutaneous administration of methotrexate, which is predominantly (85%) excreted as unchanged drug with a t1/2beta of up to 50 hours. Thus, renal function is the major determinant for disposition of methotrexate. Cyclosporin is slowly and incompletely absorbed. It is extensively metabolised by CYP3A4/5 in the liver and intestine (median t1/2beta and clearance 7.9 hours and 0.46 L/h/kg, respectively), and inhibitors and inducers of CYP3A4 can modify response and toxicity. Infliximab is predominantly distributed to the vascular compartment and eliminated with a t1/2beta between 10 and 14 days. No accumulation was observed when it was administered at intervals of 4 or 8 weeks. Methotrexate may reduce the clearance of infliximab from serum.

Cyclosporine therapeutic and toxic effects may be related to different cyclosporine concentration zones in plasma

Different cyclosporine concentration zones can exist in plasma due to the temperature dependency in distribution and association, therefore cyclosporine therapeutic and toxic effects may partially be related to these concentration zones.

Oral cyclosporin in refractory inflammatory bowel disease

BACKGROUND

The role of cyclosporin in patients with severe, refractory inflammatory bowel disease is unclear.

METHODS

A seven year retrospective review of patients treated with oral cyclosporin for inflammatory bowel disease refractory to conventional medical therapy was undertaken.

RESULTS

Twenty-eight patients (13 ulcerative colitis and 15 Crohn's disease) received oral cyclosporin for a mean of nine months (range 0.25-27 months). Within four weeks of starting cyclosporin, a complete clinical response occurred in 15 patients (nine with ulcerative colitis and six with Crohn's colitis), in whom conventional maintenance treatment was instituted concurrently. The clinical response was sustained during cyclosporin treatment in ten, but maintained after cyclosporin withdrawal in only five patients (18% of entire study group). Four of the five patients who relapsed after cyclosporin withdrawal had failed previously to respond to azathioprine. None of the five patients with continuing remission after cyclosporin withdrawal had received azathioprine in the past. There were three clinically significant infections and 14 cases of impaired renal function during treatment.

CONCLUSIONS

Oral cyclosporin induces remission in some patients with severe ulcerative colitis or Crohn's colitis, but its benefits in cases refractory to azathioprine are over-shadowed by a high frequency of relapse after drug withdrawal.

Clinical outcome following treatment of refractory inflammatory and fistulizing Crohn's disease with intravenous cyclosporine

OBJECTIVE

To determine outcome following treatment of refractory Crohn's disease with intravenous (i.v.) cyclosporine (CYA).

METHODS

The medical records of 18 patients with refractory Crohn's disease treated with i.v. CYA were reviewed. Nine patients had refractory inflammatory Crohn's disease and nine patients had complex fistulizing Crohn's disease. All patients were initially treated with i.v. CYA (4 mg/kg/day). Patients who responded were converted to standard oral CYA. Patient outcomes were classified as complete response, partial response, or nonresponse.

RESULTS

Four of nine patients with severe inflammatory Crohn's disease and seven of nine patients with fistulizing Crohn's disease had a partial response to i.v. CYA. Four of four responding patients in the inflammatory group and four of six responding patients in the fistulizing group (plus one initial nonresponder) maintained or improved their response during oral CYA therapy. After discontinuing oral CYA, all four patients in the inflammatory group and five of seven patients in the fistulizing group relapsed despite 1-17 wk of concomitant treatment with azathioprine or 6-mercaptopurine (AZA/6MP). Two patients who received overlapping CYA and AZA/6MP for 17 and 23 wk maintained long-term responses. CYA toxicity was minimal: reversible nephrotoxicity (n = 2), headache (n = 2), oral candidiasis (n = 1), paresthesia (n = 2).

CONCLUSIONS

I.v. CYA appears to benefit both refractory inflammatory and fistulizing Crohn's disease. Most patients who respond to i.v. CYA will maintain their response during oral CYA therapy. However, the majority of these patients relapse when oral CYA is discontinued, probably because of inadequate duration of overlap with the slow acting maintenance drugs, AZA/6MP.

Cyclosporine and inflammatory bowel disease: buying time

Cyclosporine is an effective drug in acute exacerbations of corticosteroid resistant ulcerative colitis, but its efficacy to maintain disease remission is not clear. Cyclosporine may not be as effective in Crohn's disease. However, being a rapidly acting immunosuppressant, cyclosporine may be a valuable therapeutic option in the short-term to treat corticosteroid resistant Crohn's disease and ulcerative colitis.

Review article: the medical management of Crohn's disease

The choice of medical therapies for Crohn's disease continues to grow. Although our understanding of the mechanisms of the disease is incomplete, increasing knowledge of the pathogenesis of inflammation in general and Crohn's disease in particular allows targeting of therapies at various points in the immunoinflammatory cascade. In addition, the division of Crohn's disease into subtypes by location, aggressiveness, and the presence or absence of perianal and fistulizing disease allows the tailoring of medical therapy to the individual patient. For those patients with moderate to severe symptoms or frequent flares of disease activity, and those who have required surgical resection, maintenance therapy can substantially reduce the rate of recurrence. Despite these advances, available medical therapies for Crohn's disease remain imperfect, as evidenced by their sometimes substantial toxicities and the continued frequent need for surgery.

Clinical pharmacology in gastroenterology: development of new forms of treatment of inflammatory bowel disease

Kinetic-dynamic aspects of the development of slow-release mesalazine, Pentasa (now an established treatment of inflammatory bowel disease (IBD)), and cyclosporin, a T cell selective immunosuppressant (still in the investigative phase), are reviewed as examples of Danish contributions at an early stage to international, clinical drug research. Apart from increasing the therapeutic options for patients with IBD, current and future studies with these (and other) drugs may add important clues to a more precise understanding of the basic pathogenetic mechanisms (e.g. cytokines, adhesion molecules) involved in these diseases. The future development and clinical implementation of novel drug designs in IBD and other gastrointestinal diseases may be expected to benefit from a continued or even closer collaboration between clinical gastroenterologists and basic research institutions, including the pharmaceutical industry at an early stage.

Is there clinical, epidemiological and molecular evidence for two forms of Crohn's disease?

Crohn's disease is an idiopathic chronic panenteric intestinal inflammatory disease. Data concerning the pathogenesis of, and the immune responses occurring in, Crohn's disease are often conflicting. Current therapy is empirical and either non-specifically immunosuppressive or surgically ablative in nature. Although controversial, Crohn's disease may be thought of as having two different presentations, an aggressive fistulizing form and an indolent obstructive form. This is analogous to the tuberculoid and lepromatous manifestations of leprosy. If correct, this subclassification may provide key insights into the pathogenesis and differing host immune responses in Crohn's disease and also allow the development of more rational therapies.

Pharmacokinetics of orally administered cyclosporine in patients with Crohn's disease

Cyclosporine pharmacokinetics were reported to be influenced in patients with Crohn's disease. To explore the relationship between Crohn's disease and cyclosporine pharmacokinetics, this investigation was performed in 20 patients with varying Crohn's Disease Activity Index (CDAI). A single oral dose of 300 mg of cyclosporine was given and serial blood samples were obtained over 52 hours. Cyclosporine whole blood concentrations were determined by a specific monoclonal radioimmunoassay. Pharmacokinetic parameters were comparable with those of healthy volunteers. No statistically significant difference between the pharmacokinetic parameters of the patients with CDAI values less than 150 and those with CDAI values 150 or greater could be shown. Although several factors associated with the pathology of Crohn's disease theoretically could influence the pharmacokinetics of orally administered cyclosporine, this investigation did not identify statistically significant differences in cyclosporine pharmacokinetics in Crohn's disease patients with different disease activities or different localization of inflammation as compared with healthy volunteers. However, if large parts of the small bowel were removed, a decrease of absorption of cyclosporine could be observed. In any case, it is important to be aware of the clinical variability of Crohn's disease and its potential implications in cyclosporine absorption.