Granisetron
Granisetron. Selective 5-HT3 receptor antagonist — same target class as ondansetron. Used for chemotherapy-induced + post-operative nausea and… Oral half-life 6.9 h.
Selective 5-HT3 receptor antagonist — same target class as ondansetron. Used for chemotherapy-induced + post-operative nausea and vomiting. Available oral, IV, and transdermal patch (Sancuso) for sustained-release CINV prophylaxis.
PK: the transdermal half-life of 35.9 h was the worst misfiling found — it is an APF530 SUBCUTANEOUS POLY(ORTHOESTER) DEPOT value (PMID:27186139) stored under a patch and attributed to a paper that says 36. The patch figure of 36 h is itself ABSORPTION RATE-LIMITED, not disposition: the same abstract puts maximal concentration at 48 h post-application. The intravenous row had no arm in its old citation; it is re-sourced to Allen 1994 (PMID:8039536), 24 healthy males, verbatim "mean volumes of distribution ranging from 186-264 l" and "Mean t1/2 values ranged from 4.1 to 6.3 h" — stated lower endpoints are stored, and that true volume now serves all three routes since disposition is route-independent. Oral half-life 6.9 h is from the granisetron-alone arm of PMID:12867217; the stored 9 h appears nowhere. Oral F 0.6 dropped: the nearest literature match is an ED50 oral-to-intravenous POTENCY RATIO in anaesthetised rats, not a fraction absorbed. ka 1.5 /h dropped.
Pharmacokinetics
- Oral — t½ 6.9 h · Vd 186 L
- IV — t½ 4.1 h · F 100% · Vd 186 L
- Transdermal — t½ 36 h · F 100% · Vd 186 L
Sources: PMID:8818349, PMID:8039536, PMID:12867217, PMID:27186139