Riluzole
Riluzole. Glutamate release inhibitor — blocks voltage-gated Na+ channels presynaptically + reduces glutamate-induced excitotoxicity. First… Oral half-life 12 h.
Glutamate release inhibitor — blocks voltage-gated Na+ channels presynaptically + reduces glutamate-induced excitotoxicity. First FDA-approved drug for ALS; modest survival benefit (~3 months). CYP1A2 substrate.
PK: F 0.6 is verbatim and genuinely ABSOLUTE — "The mean absolute oral bioavailability of riluzole (50-mg tablet) was approximately 60%" — and is the only fully supported stored value in its group. The half-life of 12 h is retained as a LABEL-derived figure: the cited paper says only that it "appeared to be independent of dose" and no indexed abstract states a number. ka 1.4 /h dropped as a Tmax collision, the paper reporting a peak at "1.0 hour to 1.5 hours". V 245 L dropped: it is an apparent volume from the approval document and pairing it with a measured absolute bioavailability would double-count absorption. CAVEAT: clearance varies widely — 32% lower in women and 36% lower in non-smokers, with 51% between-subject variability (PMID:9390108).
Pharmacokinetics
- Oral — t½ 12 h · F 60%
Sources: PMID:9549636, PMID:9390108