Piroxicam
Piroxicam. Non-selective COX inhibitor (oxicam/enolic-acid NSAID). Very long t½ (~38 h) enables once-daily dosing; substantial accumulation… Oral half-life 38 h.
Non-selective COX inhibitor (oxicam/enolic-acid NSAID). Very long t½ (~38 h) enables once-daily dosing; substantial accumulation, steady state in 1–2 weeks.
PK: MY LONG-HALF-LIFE PRIOR HELD AND THE HALF-LIFE IS UNTOUCHED - 37.5 h is verbatim and correctly the FASTING arm rather than a cross-arm average, independently corroborated by a cimetidine study control arm at 37.36 h. Two other values fail. ka 1.02 is the cleanest back-derivation in this batch: with the stored half-life it solves to Tmax 4.0046 h, within five thousandths of a round 4. And V 10 L IS CLASS 6 DIAGNOSED FROM THE SOURCE OWN WORDING RATHER THAN FROM RECORD SHAPE - the abstract says "volume of distribution DIVIDED BY availability, 0.140 or 0.136 liter/kg" - so an independent F 0.95 applied it twice; it was also a 70-kg scaling rather than a quoted litre value. It becomes 11.3 L, verbatim IN LITRES, with F pinned to 1 because that figure is apparent too. The subgroup caveat is real and recorded: 11.3 is the young-men arm of "elderly women (7.8 +/- 0.4 l) ... young men (11.3 +/- 0.3 l) and elderly men (10.8 +/- 0.8 l)", and it is the only verbatim-in-litres option available. F 0.95 had no source at all - no absolute-bioavailability abstract for piroxicam exists - and the nearby 0.95 in this literature is a RELATIVE intramuscular figure for TENOXICAM.
Pharmacokinetics
- Oral — t½ 37.5 h · F 100% · Vd 11.3 L
Sources: PMID:512843, PMID:10377455, PMID:3965234