Tamsulosin
Tamsulosin. α1A-adrenergic-preferring blocker — uroselective (vs vascular) → BPH symptom relief without BP drop. Modified-release once-daily… Oral half-life 11 h.
α1A-adrenergic-preferring blocker — uroselective (vs vascular) → BPH symptom relief without BP drop. Modified-release once-daily dosing. CYP3A4 + CYP2D6 substrate. "Floppy iris syndrome" complicates cataract surgery.
PK: F 0.9 IS A PROTEIN-BINDING PERCENTAGE, AND THE DONOR WAS SITTING IN THIS RECORD OWN refs[]. PMID:10492056 states "The mean percentage of unbound 14C-tamsulosin was 0.90% in the healthy subjects", and F 0.9 is that free fraction read as a bioavailability - the confirmed collision shape, with the source already present. The real figure is verbatim and is essentially complete: "The mean absolute oral bioavailability (+/-SD) was approximated at 100 +/- 19%", measured on modified-release granules against a 0.125 mg intravenous infusion, so F becomes 1. V 16 L IS CORRECT and only its citation was wrong - "estimated at 16 +/- 4 L in the steady state", IV-derived, so class 6 does not apply. A NEAR-MISS IS RECORDED SO NOBODY UNDOES IT: another paper in this record refs[] reports "peak plasma levels of 16 ng ml(-1)", making V_L 16 look exactly like a Cmax collision, but the volume is independently verbatim. It is a coincidence. t-half 14 appears nowhere; the cited interaction study gives "from 11.4 h to 15.3 h", where 15.3 and 11.8 are the INHIBITED arms, so the control 11.4 is stored. ka 0.4 is removed because this route is flip-flop: the intravenous terminal half-life is 6.8 h against an oral 10.5-11.4 h, so the oral slope is absorption-limited and a 1.7 h absorption half-life is incoherent with it.
Pharmacokinetics
- Oral — t½ 11.4 h · F 100% · Vd 16 L
Sources: PMID:21496064, PMID:9489594, PMID:11026539, PMID:10492056, PMID:9344174