Optimal Initial Dose of Orally Administered Cyclosporine Following Intravenous Cyclosporine Therapy

Immunosuppressive drugs and the gastrointestinal tract in renal transplant patients

Gastrointestinal (GI) discomfort is common after renal transplantation and can be caused by the use of various immunosuppressive drugs. GI symptoms affect the quality of life, lead to an impaired graft survival and an increased mortality. Moreover, diseases and disturbances of the GI tract also affect the pharmacokinetics of immunosuppressive drugs. This review addresses the interaction between immunosuppressive agents and GI disorders. The GI tract is involved in the metabolism of several immunosuppressive drugs. Calcineurin inhibitors, mTor inhibitors, and corticosteroids are subjected to metabolism by the intestinal cytochrome P450 (CYP3A) and by the drug efflux pump ABCB1. Mycophenolate is partly metabolized in the stomach and intestine and undergoes enterohepatic recirculation. Gastrointestinal disturbances can lead to a modified exposure to immunosuppressive drugs. In the first and second part of this review, we focus on the role of the GI tract in the pharmacokinetics of the immunosuppressive drugs and how to adjust immunosuppressive therapy in patients with vomiting, need for tube feeding, delayed gastric emptying, intestinal resection, and diarrhea. In the third part, we review the GI adverse effects of the various immunosuppressive drugs, with special attention for diarrhea and dyspepsia. Finally, we discuss the effects of drugs used for relief of GI complaints on the exposure to immunosuppressive agents.

Cyclosporine A-based immunotherapy in adult living donor liver transplantation: accurate and improved therapeutic drug monitoring by 4-hr intravenous infusion

BACKGROUND

A paucity of data exists for evaluating therapeutic drug monitoring in association with clinical outcomes of cyclosporine A (CYA) treatment in living donor liver transplantation (LDLT).

METHODS

A retrospective cohort analysis was conducted on 50 consecutive adult patients who underwent LDLT between 2001 and 2009 to investigate the feasibility and efficacy of 4-hr continuous intravenous infusion of CYA-based immunotherapy (4-hr CYA-IV, n=27) and compare the pharmacokinetic profile and short-term prognoses with an oral microemulsion formulation of CYA (CYA-ME, n=23).

RESULTS

All patients in the 4-hr CYA-IV group reached target CYA peak by day 3 compared with only 22% in the CYA-ME group (P<0.001). Adjustability to achieve the target range was easier in the 4-hr CYA-IV group compared with the CYA-ME group (P=0.017). Acute cellular rejection rate was lower in the 4-hr CYA-IV group (0%) compared with the CYA-ME group (17%, P=0.038). A subset analysis of the CYA-ME group revealed that CYA exposure was affected by external bile output (P=0.006). Patients in the CYA-ME group showed increased risk of switch to tacrolimus (35%) compared with the 4-hr CYA-IV group (7%, P=0.030). Toxicities and mortality rates were equivalent. The optimal initial dose of oral CYA at conversion from the 4-hr CYA-IV was considered to be 3-fold greater than that of the intravenous dose.

CONCLUSIONS

In LDLT, our 4-hr CYA-IV immunosuppression protocol was superior to CYA-ME oral dosing and allowed accurate therapeutic drug monitoring with excellent patient compliance.

Evaluation of the anti-hepatitis C virus effects of cyclophilin inhibitors, cyclosporin A, and NIM811

Hepatitis C virus (HCV) is a major causative agent of hepatocellular carcinoma. We recently discovered that the immunosuppressant cyclosporin A (CsA) and its analogue lacking immunosuppressive function, NIM811, strongly suppress the replication of HCV in cell culture. Inhibition of a cellular replication cofactor, cyclophilin (CyP) B, is critical for its anti-HCV effects. Here, we explored the potential use of CyP inhibitors for HCV treatment by analyzing the HCV replicon system. Treatment with CsA and NIM811 for 7 days reduced HCV RNA levels by 2-3 logs, and treatment for 3 weeks reduced HCV RNA to undetectable levels. NIM811 exerted higher anti-HCV activity than CsA at lower concentrations. Both CyP inhibitors rapidly reduced HCV RNA levels even further in combination with IFNalpha without modifying the IFNalpha signal transduction pathway. In conclusion, CyP inhibitors may provide a novel strategy for anti-HCV treatment.