|
Absorption
Bioavailability is approximately 50% because of first-pass metabolism (oral doseforms). Food decreases T max and C max .
Immediate-release tablets
T max is approximately 1 h.
Extended-release (ER) tablets
T max is approximately 5.3 h.
Delayed-release tablets (50 mg dose)
T max is approximately 2.3 h.
Solaraze topical gel
Following application of 2 g 3 times daily for 6 days, mean AUC is 9 ng•h/mL, mean C max is 4 ng/mL, and mean T max is 4.5 h.
Topical patch
Following a single application of the patch on the upper inner arm, C max of 0.7 to 6 ng/mL was noted between 10 and 20 h of application. With twice-daily application of patch, plasma concentrations ranged from 1.3 to 8.8 ng/mL after 5 days.
Voltaren gel
C max with application of 160 mg/day is 15 ng/mL and 54 ng/mL with application of 480 mg/day. T max is 14 h with the application of 160 mg/day and 10 h with the application of 480 mg/day. The amount reaching the systemic circulation is 158 times lower with 160 mg/day compared with oral treatment.
Distribution
More than 99% protein bound (albumin). Vd is approximately 1.4 L/kg (oral).
Metabolism
Undergoes hepatic metabolism; metabolized to 5 metabolites.
Elimination
Approximately 65% is excreted in urine and 35% in the bile. The t ½ is 1 to 2 h. Plasma elimination t ½ after application of topical patch is approximately 12 h.
Special Populations
Renal Function Impairment
No differences in pharmacokinetics have been detected in studies with patients with renal function impairment.
Hepatic Function Impairment
Since hepatic metabolism accounts for 100% of diclofenac elimination, patients with hepatic disease may require reduced doses.
|
