Pharmacokinetics of bromhexine in the dog.

Bromhexine hydrochloride was administered to dogs i.v. and p.o. Plasma determinations of the unchanged drug were carried out by gas-liquid chromatography with electron-capture detection. The plasma levels obtained after i.v. administration were consistent with a two-compartment open model. Comparison of the results of i.v. and oral administration show a low bioavailability, probably due to a first pass effect.