Pharmacokinetics of tolfenamic acid in the horse.

The pharmacokinetics of tolfenamic acid were studied in five ponies after an intravenous (iv) administration (2 mg/kg bodyweight [bwt]) and in four horses after an oral administration (30 mg/kg bwt) of tolfenamic acid. The plasma levels were determined by high pressure liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). For the iv administration, a three-compartment model was used to represent the plasma concentration-time curve of the drug. The elimination half-life of the compound was 6.1 +/- 1.5 h, the total body clearance was 72.4 +/- 16.7 ml/kg bwt/h and the steady-state volume of distribution 0.32 +/- 0.11 litres/kg bwt. For the oral administration, absorbtion was delayed with a mean lag-time to absorption of 32 +/- 28 mins. The peak plasma concentration 11.1 +/- 0.69 micrograms/ml was observed after a highly variable delay ranging from 1.9 to 6.5 h post administration. The terminal half-life (4.2 +/- 0.48 h) was very similar to that obtained after iv administration. Tolfenamic acid could not be detected in equine plasma with the described analytical methods more than 48 h after drug administration.

Identification of a tolfenamic acid metabolite in the horse by gas chromatography-mass spectrometry.

A tolfenamic acid metabolite, a hydroxylated product, has been identified in equine plasma and urine samples using gas chromatography-mass spectrometry in the electron-impact and chemical-ionization modes. The method also allows the qualitative monitoring of the elimination of the drug and its metabolites from plasma. The two compounds are detected up to 48 and 24 h, respectively, after a single oral administration of a 30 mg/kg dose. The simultaneous detection of the two products increases the reliability of anti-doping control analysis.

[Pre-occlusive stenosis of the internal carotid artery. Haemodynamic study by Doppler effect, phonoangiography-oculoplethysmography and arteriography (author's transl)]. / Les sténoses pré-occlusives de l'artère carotide interne. Etude hémodynamique par: effet Doppler, phonoangiographie, oculopléthysmographie, artériographie.

The diagnosis of near total occlusion of the internal carotid artery was made on a group of 122 patients (90 symptomatic - 32 asymptomatic) by Doppler examination on one hand and carotid phonoangiography and oculoplethysmography, used together, on the other hand. The angiographic examination, including the study of the extra cranial arteries and the intra cerebral vessels, was performed. It has shown that a stenosis (greater than or equal to 90% of an internal carotid artery was the only lesion on 65 patients (53.3%) and that in 57 cases (46.7%) there were multiple lesions. 96 patients (76 symptomatic - 20 asymptomatic) were operated on. 4 patients (4.2%) died but the mortality was none in the group of 20 asymptomatic patients. 19 patients refused the operation and we have noted 7 occlusions of the internal carotid artery and 2 patients died (10.2%). On 7 patients with a surgical contra indication we have noted 1 secondary occlusion. We have to consider a near total occlusion of the internal carotid artery as an emergency. Its diagnosis by non invasive techniques must be followed by heparin therapy and angiographic examination. The carotid endarterectomy will respect the external carotid artery patency.