Diclofenac
Diclofenac. Acetic-acid NSAID — non-selective COX inhibitor with modest COX-2 preference. Higher cardiovascular risk than ibuprofen / naproxen.… Oral half-life 1.9 h.
Acetic-acid NSAID — non-selective COX inhibitor with modest COX-2 preference. Higher cardiovascular risk than ibuprofen / naproxen. CYP2C9 substrate. Hepatotoxicity warning (~1:10,000).
PK: the half-life of 1.92 h is verbatim and correctly taken from the reference-diclofenac arm rather than averaged with the nano-formulation arms. F 0.55 appears nowhere in the cited paper, whose only bioavailability statement is a relative one; the measured absolute figure of 65.1% at 25 mg against an intravenous reference now replaces it. V 14 L and ka 4 are unsourced, and the rate is refuted by the paper own 0.80 h time to peak. THE TRANSDERMAL AND INTRAMUSCULAR ROUTES ARE REMOVED, AND THE TRANSDERMAL ONE MATTERS: patch steady-state peak concentration is 3.36 ng/mL against an oral 50 mg peak of 1316 ng/mL — roughly 400-FOLD lower systemic exposure — so a transdermal row inheriting the oral block would be grossly wrong. Absorption is formulation-dependent and lagged, the enteric-coated form having a stated 2.2 h lag. The record only reference dosed a SUSTAINED-RELEASE product while the block models immediate release, and reports no kinetics at all.
Pharmacokinetics
- Oral — t½ 1.9 h · F 65%
Sources: PMID:11874389, PMID:15606444, PMID:3369245, PMID:3572745