Absorption and elimination
It is rapidly absorbed from sugar-coated tablets, oral
solution and rectal suppositories; however, an entericcoated
tablet will be absorbed slower (Novartis,
2010; Sandoz, 2008) Almost all the diclofenac will be
absorbed into the circulation but the first pass of the
liver will remove 50% before it reaches the site of action.
The half-life is 1–2 hours and it is then metabolised and
excreted through the liver and bile. (Novartis, 2010)
Clinical pharmacokinetic studies of oral diclofenac in
children have shown that a 1 mg/kg dose of diclofenac
will produce about the same exposure as a 50 mg dose would in an adult (Standing et al, 2009)