Lidocaine
Lidocaine. Amide-class local anesthetic — voltage-gated Na+ channel blocker preferentially binding the inactivated state. Local… Intranasal half-life 1.7 h.
Amide-class local anesthetic — voltage-gated Na+ channel blocker preferentially binding the inactivated state. Local infiltration, regional blocks, IV antiarrhythmic (Class IB) for ventricular arrhythmias, topical 5% patch for postherpetic neuralgia.
PK: the intranasal bioavailability of 0.26 is verbatim and is the best-sourced value on this record, "the mean bioavailability of the intranasal formulation (AUC ratio) was 0.26 +/- 0.08" — though it ranged from 0.05 to 0.48 between individuals and describes one gel formulation. The intramuscular half-life is corrected to 1.68 h ("101 min"), its own paper figure; the stored 1.66 h had been imported from the intravenous paper. V 200 L dropped from all three rows: it appears in none of the three cited abstracts and is shared with unrelated drugs. CAVEATS: the intravenous 1.66 h is the fastest of four subgroups in a paper whose thesis is that they differ, the others being 2.07 to 2.70 h; and lidocaine disposition is genuinely TWO-compartment with a distribution half-life near 3.6 min (PMID:3954094), so a one-compartment curve over-predicts early concentrations.
Pharmacokinetics
- IV — t½ 1.7 h · F 100%
- Intramuscular — t½ 1.7 h · F 100%
- Intranasal — t½ 1.7 h · F 26%
Sources: PMID:6196560, PMID:2085708, PMID:9768788, PMID:3954094, PMID:7357791