Cyclosporine is a potent immunosuppressive agent that in animals prolongs survival of allogeneic transplants involving skin, kidney, liver, heart, pancreas, bone marrow, small intestine, and lung. Cyclosporine has been demonstrated to suppress some humoral immunity and to a greater extent, cell-mediated immune reactions such as allograft rejection, delayed hypersensitivity, experimental allergic encephalomyelitis, Freund’s adjuvant arthritis, and graft vs. host disease in many animal species for a variety of organs.
The effectiveness of cyclosporine results from specific and reversible inhibition of immunocompetent lymphocytes in the G0- and G1-phase of the cell cycle. T-lymphocytes are preferentially inhibited. The T-helper cell is the main target, although the T-suppressor cell may also be suppressed. Cyclosporine also inhibits lymphokine production and release including interleukin-2.
No effects on phagocytic function (changes in enzyme secretions, chemotactic migration of granulocytes, macrophage migration, carbon clearance in vivo) have been detected in animals. Cyclosporine does not cause bone marrow suppression in animal models or man.
The immunosuppressive activity of cyclosporine is primarily due to parent drug. Following oral administration, absorption of cyclosporine is incomplete. The extent of absorption of cyclosporine is dependent on the individual patient, the patient population, and the formulation. Elimination of cyclosporine is primarily biliary with only 6% of the dose (parent drug and metabolites) excreted in urine. The disposition of cyclosporine from blood is generally biphasic, with a terminal half-life of approximately 8.4 hours (range 5-18 hours). Following intravenous administration, the blood clearance of cyclosporine (assay: HPLC) is approximately 5-7 mL/min/kg in adult recipients of renal or liver allografts. Blood cyclosporine clearance appears to be slightly slower in cardiac transplant patients.
The Neoral® Soft Gelatin Capsules (cyclosporine capsules, USP) MODIFIED and Neoral® Oral Solution (cyclosporine oral solution, USP) MODIFIED are bioequivalent. Neoral® Oral Solution diluted with orange juice or apple juice is bioequivalent to Neoral Oral Solution diluted with water. The effect of milk on the bioavailability of cyclosporine when administered as Neoral Oral Solution has not been evaluated.
The relationship between administered dose and exposure (area under the concentration versus time curve, AUC) is linear within the therapeutic dose range. The intersubject variability (total, %CV) of cyclosporine exposure (AUC) when Neoral® or Sandimmune® is administered ranges from approximately 20% to 50% in renal transplant patients. This intersubject variability contributes to the need for individualization of the dosing regimen for optimal therapy (see DOSAGE AND ADMINISTRATION). Intrasubject variability of AUC in renal transplant recipients (%CV) was 9%-21% for Neoral® and 19%-26% for Sandimmune®. In the same studies, intrasubject variability of trough concentrations (%CV) was 17%-30% for Neoral® and 16%-38% for Sandimmune®.
Neoral® has increased bioavailability compared to Sandimmune®. The absolute bioavailability of cyclosporine administered as Sandimmune® is dependent on the patient population, estimated to be less than 10% in liver transplant patients and as great as 89% in some renal transplant patients. The absolute bioavailability of cyclosporine administered as Neoral® has not been determined in adults. In studies of renal transplant, rheumatoid arthritis and psoriasis patients, the mean cyclosporine AUC was approximately 20% to 50% greater and the peak blood cyclosporine concentration (Cmax) was approximately 40% to 106% greater following administration of Neoral® compared to following administration of Sandimmune®. The dose normalized AUC in de novo liver transplant patients administered Neoral® 28 days after transplantation was 50% greater and Cmax was 90% greater than in those patients administered Sandimmune®. AUC and Cmax are also increased (Neoral® relative to Sandimmune®) in heart transplant patients, but data are very limited. Although the AUC and Cmax values are higher on Neoral® relative to Sandimmune®, the pre-dose trough concentrations (dose-normalized) are similar for the two formulations.
Following oral administration of Neoral®, the time to peak blood cyclosporine concentrations (Tmax) ranged from 1.5-2.0 hours. The administration of food with Neoral® decreases the cyclosporine AUC and Cmax. A high fat meal (669 kcal, 45 grams fat) consumed within one-half hour before Neoral® administration decreased the AUC by 13% and Cmax by 33%. The effects of a low fat meal (667 kcal, 15 grams fat) were similar.
The effect of T-tube diversion of bile on the absorption of cyclosporine from Neoral® was investigated in eleven de novo liver transplant patients. When the patients were administered Neoral® with and without T-tube diversion of bile, very little difference in absorption was observed, as measured by the change in maximal cyclosporine blood concentrations from pre-dose values with the T-tube closed relative to when it was open: 6.9±41% (range -55% to 68%).
| Pharmacokinetic Parameters (mean±SD) |
| Dose/day 1 || Dose/weight || AUC 2 || C max || Trough 3 || CL/F || CL/F |
| Patient Population || (mg/d) || (mg/kg/d) || (ng·hr/mL) || (ng/mL) || (ng/mL) || (mL/min) || (mL/min/kg) |
| De novo renal transplant4||597±174||7.95±2.81||8772±2089||1802±428||361±129||593±204||7.8±2.9|
|Week 4 (N=37)|
|Stable renal transplant4||344±122||4.10±1.58||6035±2194||1333±469||251±116||492±140||5.9±2.1|
| De novo liver transplant5||458±190||6.89±3.68||7187±2816||1555±740||268±101||577±309||8.6±5.7|
|Week 4 (N=18)|
| De novo rheumatoid arthritis6||182±55.6||2.37±0.36||2641±877||728±263||96.4±37.7||613±196||8.3±2.8|
| De novo psoriasis6||189±69.8||2.48±0.65||2324±1048||655±186||74.9±46.7||723±186||10.2±3.9|
|Week 4 (N=18)|
1Total daily dose was divided into two doses administered every 12 hours
2AUC was measured over one dosing interval
3Trough concentration was measured just prior to the morning Neoral® dose, approximately 12 hours after the previous dose
4Assay: TDx specific monoclonal fluorescence polarization immunoassay
5Assay: Cyclo-trac specific monoclonal radioimmunoassay
6Assay: INCSTAR specific monoclonal radioimmunoassay
Cyclosporine is distributed largely outside the blood volume. The steady state volume of distribution during intravenous dosing has been reported as 3-5 L/kg in solid organ transplant recipients. In blood, the distribution is concentration dependent. Approximately 33%-47% is in plasma, 4%-9% in lymphocytes, 5%-12% in granulocytes, and 41%-58% in erythrocytes. At high concentrations, the binding capacity of leukocytes and erythrocytes becomes saturated. In plasma, approximately 90% is bound to proteins, primarily lipoproteins. Cyclosporine is excreted in human milk. (See PRECAUTIONS, Nursing Mothers)
Cyclosporine is extensively metabolized by the cytochrome P-450 3A enzyme system in the liver, and to a lesser degree in the gastrointestinal tract, and the kidney. The metabolism of cyclosporine can be altered by the co-administration of a variety of agents . (See PRECAUTIONS, Drug Interactions) At least 25 metabolites have been identified from human bile, feces, blood, and urine. The biological activity of the metabolites and their contributions to toxicity are considerably less than those of the parent compound. The major metabolites (M1, M9, and M4N) result from oxidation at the 1-beta, 9-gamma, and 4-N-demethylated positions, respectively. At steady state following the oral administration of Sandimmune®, the mean AUCs for blood concentrations of M1, M9, and M4N are about 70%, 21%, and 7.5% of the AUC for blood cyclosporine concentrations, respectively. Based on blood concentration data from stable renal transplant patients (13 patients administered Neoral® and Sandimmune® in a crossover study), and bile concentration data from de novo liver transplant patients (4 administered Neoral®, 3 administered Sandimmune®), the percentage of dose present as M1, M9, and M4N metabolites is similar when either Neoral® or Sandimmune® is administered.
Only 0.1% of a cyclosporine dose is excreted unchanged in the urine. Elimination is primarily biliary with only 6% of the dose (parent drug and metabolites) excreted in the urine. Neither dialysis nor renal failure alter cyclosporine clearance significantly.
(See PRECAUTIONS, Drug Interactions) When diclofenac or methotrexate was co-administered with cyclosporine in rheumatoid arthritis patients, the AUC of diclofenac and methotrexate, each was significantly increased. (See PRECAUTIONS, Drug Interactions) No clinically significant pharmacokinetic interactions occurred between cyclosporine and aspirin, ketoprofen, piroxicam, or indomethacin.
Pharmacokinetic data from pediatric patients administered Neoral® or Sandimmune® are very limited. In 15 renal transplant patients aged 3-16 years, cyclosporine whole blood clearance after IV administration of Sandimmune® was 10.6±3.7 mL/min/kg (assay: Cyclo-trac specific RIA). In a study of 7 renal transplant patients aged 2-16, the cyclosporine clearance ranged from 9.8-15.5 mL/min/kg. In 9 liver transplant patients aged 0.6-5.6 years, clearance was 9.3±5.4 mL/min/kg (assay: HPLC).
In the pediatric population, Neoral® also demonstrates an increased bioavailability as compared to Sandimmune®. In 7 liver de novo transplant patients aged 1.4-10 years, the absolute bioavailability of Neoral® was 43% (range 30%-68%) and for Sandimmune® in the same individuals absolute bioavailability was 28% (range 17%-42%).
| Pediatric Pharmacokinetic Parameters (mean±SD) |
| Dose/day || Dose/weight || AUC 1 || Cmax || CL/F || CL/F |
| Patient Population || (mg/d) || (mg/kg/d) || (ng·hr/mL) || (ng/mL) || (mL/min) || (mL/min/kg) |
|Stable liver transplant2|
|Age 2-8, Dosed TID (N=9)||101±25||5.95±1.32||2163±801||629±219||285±94||16.6±4.3|
|Age 8-15, Dosed BID (N=8)||188±55||4.96±2.09||4272±1462||975±281||378±80||10.2±4.0|
|Stable liver transplant3|
|Age 3, Dosed BID (N=1)||120||8.33||5832||1050||171||11.9|
|Age 8-15, Dosed BID (N=5)||158±55||5.51±1.91||4452±2475||1013±635||328±121||11.0±1.9|
|Stable renal transplant3|
|Age 7-15, Dosed BID (N=5)||328±83||7.37±4.11||6922±1988||1827±487||418±143||8.7±2.9|
1AUC was measured over one dosing interval
2Assay: Cyclo-trac specific monoclonal radioimmunoassay
3Assay: TDx specific monoclonal fluorescence polarization immunoassay
Comparison of single dose data from both normal elderly volunteers (N=18, mean age 69 years) and elderly rheumatoid arthritis patients (N=16, mean age 68 years) to single dose data in young adult volunteers (N=16, mean age 26 years) showed no significant difference in the pharmacokinetic parameters.