Theobromine
Theobromine, an alkaloid. Methylated xanthine found in cocoa. Weaker adenosine A1/A2A antagonist than caffeine (A2A Ki ~14 µM vs caffeine's ~2.4… Oral half-life 7.1 h.
Methylated xanthine found in cocoa. Weaker adenosine A1/A2A antagonist than caffeine (A2A Ki ~14 µM vs caffeine's ~2.4 µM) and weaker PDE inhibitor. Longer plasma t½ (~7 h vs caffeine's ~5 h). Mild vasodilator. Highly toxic to dogs + cats (slow xanthine metabolism in those species).
F 0.9 REMOVED as an R6 stored default, and the one F-shaped figure in the citation is a DIFFERENT QUANTITY: PMID:3979003 states "Relative bioavailability of theobromine in chocolate was 80% that of theobromine in solution" — relative, chocolate-versus-solution, and 80 rather than 90. Read as an absolute F it would not be 0.9 either. Numerically a no-op against the 0.9 default. PK: THE STORED ABSORPTION RATE WAS THE SOLVER DEFAULT WEARING A CITATION. A ka of 1.0/h is exactly what resolvePk substitutes when the field is ABSENT, and no source on this record states one. Removing it is NUMERICALLY A NO-OP — the resolver supplies the identical number — so no curve moves; what changes is that the record stops asserting an absorption rate it never measured. This is the same shape already found on a volume of 35 L, which is likewise the default at the seventy-kilogram reference. THE WIDER DEBT IS LEFT ALONE ON PURPOSE: twelve values account for 152 of the 276 authored absorption rates, but the other eleven are NOT the default, so deleting those would move their curves rather than leave them, which is the error this audit spent a batch documenting.
Pharmacokinetics
- Oral — t½ 7.1 h · Vd 56 L
Related compounds
- Caffeine — synergistic
Sources: PMID:3979003