Conversion From Cyclosporine to Once-Daily Tacrolimus on 50:1 mg Basis: A Short-Term Pilot Study

OBJECTIVES

In addition to graft dysfunction, renal transplant recipients on cyclosporine may be switched to tacrolimus to reduce its drug-related secondary clinical effects and undesirable cosmetic side effects. However, the dose level of once-daily tacrolimus for these patients has yet to be established. The objective of this prospective study was to confirm the safety of converting stable renal transplant recipients on cyclosporine to once-daily tacrolimus at a 50:1 mg ratio.

MATERIALS AND METHODS

Our study enrolled 17 patients receiving cyclosporine who were observed for 3 months. Graft biopsies did not reveal any acute rejection, and the conversion ratio to once-daily tacrolimus was 50:1 mg. Dose adjustments were made to achieve a target tacrolimus trough concentration of 3 to 5 ng/mL at 2 weeks, and graft biopsies were taken after the 3-month observation period.

RESULTS

Dose adjustment was required in 7 recipients (41.2%) within 3 months of conversion. None of the recipients had acute cellular rejection or C4d deposition, and the mean estimated glomerular filtration rate of 38.7 ± 11.0 mL/min/1.73 m2 at baseline was significantly improved to 42.0 ± 10.0 mL/min/1.73 m2 at month 3.

CONCLUSIONS

Although recipients of renal transplant can be forced to discontinue cyclosporine administration due to undesirable adverse effects, our study showed that a once-daily dose of tacrolimus may be safe when administered at a conversion ratio of 50:1.

Long-lasting immunosuppressive effects of tacrolimus-loaded micelle NK61060 in preclinical arthritis and colitis models

AIM

Tacrolimus (TAC) is an important drug for inflammatory diseases. However, TAC has several limitations, such as variable trough concentrations among individuals and a high medication frequency. In this study, we created NK61060, a novel micellar TAC formulation, to circumvent these disadvantages.

MATERIALS & METHODS

Immunosuppressive activity of NK61060 was determined in the collagen-induced arthritis rat model, mannan-induced arthritis mouse model and dextran sodium sulfate-induced colitis mouse model. The pharmacokinetics and toxicology of NK61060 were evaluated in those models.

RESULTS

In arthritis and colitis models, NK61060 exhibited superior immunosuppressive activity compared with that of TAC. Pharmacokinetic and toxicological analyses indicated that NK61060 had a wider safety margin and could be administered at a reduced medication frequency.

CONCLUSION

NK61060 mitigates the trough concentration variability and the medication frequency and it may be a safer and more effective option for use in clinical settings. Further studies are needed to determine its clinical usefulness.

Pharmacokinetics of prolonged-release tacrolimus and implications for use in solid organ transplant recipients

Prolonged-release tacrolimus was developed as a once-daily formulation with ethylcellulose as the excipient, resulting in slower release and reduction in peak concentration (Cmax ) for a given dose compared with immediate-release tacrolimus, which is administered twice daily. This manuscript reviews pharmacokinetic information on prolonged-release tacrolimus in healthy subjects, in transplant recipients converted from immediate-release tacrolimus, and in de novo kidney and liver transplant recipients. As with the immediate-release formulation, prolonged-release tacrolimus shows a strong correlation between trough concentration (Cmin ) and area under the 24-hour time-concentration curve (AUC24 ), indicating that trough whole blood concentrations provide an accurate measure of drug exposure. We present the pharmacokinetic similarities and differences between the two formulations, so that prescribing physicians will have a better understanding of therapeutic drug monitoring in patients receiving prolonged-release tacrolimus.

Comparison of pharmacokinetics and pathology for low-dose tacrolimus once-daily and twice-daily in living kidney transplantation: prospective trial in once-daily versus twice-daily tacrolimus

BACKGROUND

A prolonged-release formulation of tacrolimus (Tacrolimus QD) was developed to allow once-daily dosing and to have similar safety and efficacy profiles to twice-daily tacrolimus (Tacrolimus BID). This study compared the pharmacokinetics (PK) and renal pathology by protocol biopsy in de novo living kidney transplant recipients treated with either low-dose Tacrolimus QD or Tacrolimus BID.

METHODS

Between November 2009 and January 2011, 102 consecutive adult patients were randomized to receive either low-dose Tacrolimus QD or Tacrolimus BID. All patients underwent PK study and protocol biopsy on postoperative day 14. Additional protocol biopsies were performed between 6 and 12 months after renal transplantation.

RESULTS

During the 1-year follow up, the incidence of biopsy-proven acute rejection and toxic tubulopathy was low and similar in both groups. Twenty-four hours area under the curve (AUC0-24) was not different in both groups (285 ± 78.7 and 281 ± 62.4 ng hr/mL in Tacrolimus QD and Tacrolimus BID, respectively). C0 was well correlated with AUC0-24 in both groups and AUC0-24 between 260 and 280 in the Tacrolimus QD group was achieved by 6 to 8 ng/mL of C0. Acute nephrotoxicity was less than 10% in both groups without any clinical manifestation.

CONCLUSION

Clinical efficacy, safety, and PK profile of Tacrolimus QD is same as those of Tacrolimus BID.

Comparison of adverse drug reaction profiles of two tacrolimus formulations in rats

Tacrobell(®) (TB) is a generic tacrolimus which showed the comparable efficacy to original product, Prograf(®) (PG) in renal transplantation, but toxicity between two drugs is unclear. The aim of this study was to compare the toxicity between these two formulations. TB and PG (0.5, 1 and 2 mg/kg/day) was administered to rats for 4 weeks. The rat survival rate, kidney, liver and pancreas injury was investigated. The survival rate was similar between TB- and PG-treated rats. TB and PG induced renal dysfunction in a dose-dependent manner. Compared to PG treatment in equal dose, TB treatment reduced urinary creatinine clearance in a less degree and renal interstitial fibrosis was comparable between two regimens. The r-glutamyl transpeptidase was aggravated by tacrolimus treatment, and this was not different between TB and PG treatment. In the intraperitoneal glucose tolerance test, a significant diabetogenic effect was observed in all tacrolimus treated-rats. The glucose tolerance of TB-treated rats was similar to those of PG-treated rats in each dose. The decrement in pancreatic β-cell mass by tacrolimus showed the dose-dependent response and it was comparable between TB and PG treatment. In conclusion, TB is similar to PG in terms of nephrotoxicity, hepatoxicity and diabetogenic effect.