Brompheniramine

pharmacological · nervous · Oral

Brompheniramine. First-generation H1 antagonist — bromine analog of chlorpheniramine. OTC component of multi-ingredient cold formulations. Same… Oral half-life 25 h.

First-generation H1 antagonist — bromine analog of chlorpheniramine. OTC component of multi-ingredient cold formulations. Same sedation + anticholinergic profile.

PK: Simons 1982 (PMID:6128358), 7 adults, racemate: verbatim "mean serum half-life value was 24.9 +/- 9.3 hr … mean volume of distribution was 11.7 +/- 3.1 L/kg" (× 70 kg = 820 L; apparent V/F since no IV arm), Tmax 3.1 h. The formerly stored ka 2 /h implied Tmax under an hour and F 0.7 was unsourced; both removed. H1 affinity remains unauthored — no abstract names a brompheniramine H1 Ki (see AUTHORING_GAPS). PK: MY PRIOR IS REFUTED AND THE RECORD IS RIGHT. Both stored values are verbatim in the cited abstract — "The mean serum half-life value was 24.9 +/- 9.3 hr, the mean clearance rate was 6.0 +/- 2.3 ml/min/kg, and the mean volume of distribution was 11.7 +/- 3.1 L/kg" — the transplant check against chlorpheniramine is NEGATIVE, and the earlier pass that removed an invented absorption rate and bioavailability had ALREADY DONE THE WHOLE JOB. THE APPARENT THREE-FOLD VOLUME GAP BETWEEN THE TWO ANALOGUES IS NOT A DEFECT AND IT RESOLVES: chlorpheniramine 230 L is a true intravenous-derived volume, this one is an apparent volume with no intravenous arm ("the absolute bioavailability is unknown because no intravenous formulations are available"), and applying chlorpheniramine own bioavailability to it lands on chlorpheniramine own value. THE TWO RECORDS AGREE. The one actionable item is small and real: with no bioavailability stored the solver substitutes 0.9 against a volume that ALREADY CONTAINS IT, dividing by absorption twice, so it is pinned at unity in the same convention this catalogue already uses elsewhere. DOSE MOIETY: THE 1.36-FOLD CASE FOUND ALONGSIDE LITHIUM. Batch 10 acquitted every stored value on this record and noted in passing that the molecular weight is the free base while the four milligram dose is the MALEATE — raised then only because it is systematic across the first-generation antihistamines. It is not cosmetic once the dose feeds the curve: the solver was dividing maleate mass by a free-base volume. Declared, and the sibling chlorpheniramine is corrected in the same pass.

Pharmacokinetics

Sources: PMID:6128358