Paclitaxel
Paclitaxel. Taxane microtubule stabilizer — binds β-tubulin, prevents depolymerization, freezes the mitotic spindle. Originally from Pacific yew… IV half-life 8.6 h.
Taxane microtubule stabilizer — binds β-tubulin, prevents depolymerization, freezes the mitotic spindle. Originally from Pacific yew bark. Workhorse of breast + ovarian + lung regimens. CYP3A4/2C8 substrate. Hypersensitivity to Cremophor EL vehicle requires premedication; abraxane (albumin-bound) sidesteps this.
PK: A PER-SQUARE-METRE DOSE ENTERED AS FLAT MASS, AND A VOLUME SCALED AT A DIFFERENT BODY SURFACE THAN THE DOSE. Its citation states every dose and the volume in per-square-metre units — "half-lives of the first and second phases after a 275 mg/m2 dose were 0.32 and 8.6 h" and "The apparent volume of distribution was 55 liters/m2" — while the record stored the raw dose numerals as milligrams and a volume of 99 L, which is that verbatim figure scaled at 1.8 square metres. THE TWO USED DIFFERENT BODIES. Both now use 1.73, the same reference doxorubicin was corrected to. THE ONE VERBATIM CONCENTRATION IN THAT ABSTRACT CONFIRMS THE DIRECTION: it reports a peak "with a dose of 275 mg/m2 ... approximately 8 microM", which the corrected convention reproduces to within 1.4-fold where the stored one was 2.5-fold low. TWO CAVEATS ARE FLAGGED AND NOT ACTED ON: the half-life kept is the terminal one of a profile the same sentence calls biphasic, which is the class-12 shape even though the abstract offers no clearance to test it against; and this drug is widely described as having vehicle-mediated non-linear disposition, which this abstract does not state and which I therefore do not assert.
Pharmacokinetics
- IV — t½ 8.6 h · F 100% · Vd 95.15 L
Sources: PMID:2882837