Somatostatin
Somatostatin, a peptide. Two primary forms (SST-14, SST-28) produced from preprosomatostatin. Binds SSTR1-5 (5 GPCR subtypes). Broad inhibitory… IV half-life 0 h.
Two primary forms (SST-14, SST-28) produced from preprosomatostatin. Binds SSTR1-5 (5 GPCR subtypes). Broad inhibitory profile: blocks GH, insulin, glucagon, gastrin, secretin, VIP, and motilin release; also inhibits CNS neurotransmission. Extremely short plasma t½ (~2 min) mandates continuous infusion. Clinical analogs octreotide, lanreotide, and pasireotide carry the same profile with extended t½.
PK: Sheppard 1979 (PMID:422706), normal volunteers, IV infusion, verbatim "In normal subjects, the t 1/2 of the first component varied from 1.1-3.0 min". The stored 0.033 h is the midpoint of that range; 0.034 h (2.05 min) is the exact midpoint, kept with the range quoted so the spread is visible, and the abstract is explicit that decay is biphasic. The ka of 60 /h was removed: it was the registry sentinel for instantaneous input, which the solver ignores on IV routes anyway, and it was sitting on a citation that says nothing about absorption. The same paper gives a metabolic clearance rate of 1949 +/- 250 mL/min if a clearance term is wanted.
Pharmacokinetics
- IV — t½ 2 min
Sources: PMID:7911441