Alprazolam
Alprazolam. Benzodiazepine — positive allosteric modulator of GABA-A at the α1/α2/α3/α5-BZ site. Triazole ring confers short t½ + high potency.… Oral half-life 12 h.
Benzodiazepine — positive allosteric modulator of GABA-A at the α1/α2/α3/α5-BZ site. Triazole ring confers short t½ + high potency. Greater anti-panic activity than diazepam.
PK: Smith 1984 (PMID:6152055), 6 healthy men, 1 mg IV and 1 mg oral crossover — the only true-IV alprazolam study — verbatim "volume of distribution (Vd) 0.72 and 0.84 l/kg", "elimination half-life (t1/2) 11.7 and 11.8 h" and "The mean fraction absorbed after oral administration was 0.92". The oral V is 0.84 L/kg x 70 kg = 58.8 L. The SL half-life was 16 h, copied from the PO row: its own paper (PMID:3680603) states 11.7 h. V 80 L and F 0.9 were a shared default appearing in neither abstract, and ka 2.5 /h has no relationship to the cited paper Tmax of 1.5 h. A population ka of 1.1 /h exists (PMID:8491063) but is from 94 psychiatric inpatients and is not imported.
Pharmacokinetics
- Oral — t½ 11.8 h · F 92% · Vd 58.8 L
- Sublingual — t½ 11.7 h
Related compounds
- Opioids — major
Sources: PMID:1684924, PMID:26143953, PMID:6152055, PMID:8491063, PMID:2567646