Nicardipine is completely absorbed following oral doses administered as capsules, and the systemic bioavailability is about 35% following a 30-mg oral dose at steady-state. The pharmacokinetics of nicardipine are nonlinear due to saturable hepatic first-pass metabolism.

Following oral administration of CARDENE SR, plasma levels are detectable as early as 20 minutes and maximal plasma levels are achieved as a broad peak generally between 1 and 4 hours. The average terminal plasma half-life of nicardipine is 8.6 hours. Following oral administration increasing doses result in disproportionate increases in plasma levels. Steady-state C values following 30-, 45- and 60-mg doses every 12 hours averaged 13.4, 34.0, and 58.4 ng/mL, respectively. Hence, increasing the dose twofold increases maximum plasma levels 4-fold to 5-fold. A similar disproportionate increase is observed with AUC. In comparison with equivalent daily doses of CARDENE capsules, CARDENE SR shows a significant reduction in C . CARDENE SR also has somewhat lower bioavailability than CARDENE except at the highest dose. Minimum plasma levels produced by equivalent daily doses are similar. CARDENE SR thus exhibits significantly reduced fluctuation in plasma levels in comparison to CARDENE capsules. maxmax

When CARDENE SR was administered with a high-fat breakfast, mean C was 45% lower, AUC was 25% lower and trough levels were 75% higher than when CARDENE SR was given in the fasting state. Thus, taking CARDENE SR with the meal reduced the fluctuation in plasma levels. Clinical trials establishing the safety and efficacy of CARDENE SR were carried out in patients without regard to the timing of meals. max

Nicardipine is highly protein bound (>95%) in human plasma over a wide concentration range.

Nicardipine is metabolized extensively by the liver; less than 1% of intact drug is detected in the urine. Following a radioactive oral dose in solution, 60% of the radioactivity was recovered in the urine and 35% in feces. Most of the dose (over 90%) was recovered within 48 hours of dosing. Nicardipine does not induce its own metabolism and does not induce hepatic microsomal enzymes.

Nicardipine plasma levels following administration of CARDENE SR in hypertensive patients with moderate renal impairment (creatinine clearance 10 to 55 mL/min) were significantly higher following a single-oral dose and at steady-state than in hypertensive patients with mildly impaired renal function (creatinine clearance >55 mL/min). After 45-mg CARDENE SR bid at steady-state, C and AUC were 2-fold to 3-fold higher in the patients with moderate renal impairment. Plasma levels in patients with mildly impaired renal function were similar to those in normal subjects. max

In patients with severe renal impairment undergoing routine hemodialysis, plasma levels following a single dose of CARDENE SR were not significantly different from those patients with mildly impaired renal function.

Because nicardipine is extensively metabolized by the liver, the plasma levels of the drug are influenced by changes in hepatic function. Following administration of CARDENE capsules, nicardipine plasma levels were higher in patients with severe liver disease (hepatic cirrhosis confirmed by liver biopsy or presence of endoscopically-confirmed esophageal varices) than in normal subjects. After 20-mg CARDENE bid at steady-state, C and AUC were 1.8-fold and 4-fold higher, and the terminal half-life was prolonged to 19 hours in these patients. CARDENE SR has not been studied in patients with severe liver disease. max