Tolfenamic acid

Sidelmann UG, U Braumann, M Hofmann, M Spraul, JC Lindon, JK Nicholson, SH Hansen (1997) Directly coupled 800 MHz HPLC-NMR spectroscopy of urine and its application to the identification of the major phase II metabolites of tolfenamic acid. Anal Chem 69 607-612. 

Two NSAIDs have a proven, though modest, preventive effect tolfenamic acid and naproxene. 

Tolfenamic acid is used as an injectable formulation in cattle and swine. In rats and target animals, tolfenamic acid is metabolized by hydroxylation either of the methyl or the methylchlorophenyl group producing two metabolites further oxidation of the hydroxymethyl group to the corresponding aldehyde or carboxylic acid can produce two additional metabolites. The two hydroxylated metabolites of tolfenamic acid, N-(2-hydroxymethyl-3-chlorophenyl)-anthranilic acid and N-(2-hydroxymethyl-3-chloro-4-hydroxyphenyl)-anthranilic acid, are much less potent than the parent compound in terms of anti-inflammatory and analgesic... 

Intravenous administration followed by intramuscular administration 24 h later of radiolabeled tolfenamic acid in dairy cattle at a dosage of 4 mg/kg bw or two intramuscular administrations of 2 mg/kg bw showed tliat at 8 days after the cessation of treatment, the concentrations of residues in liver, kidney, and injection site were 0.07, 0.09, and 39.6 ppm tolfenamic acid equivalent. The proportion of the parent drug relative to total residues was 51% in liver, 56.7% in kidney, and 78% at the injection site. Residues of tolfenamic acid could not be detected in milk at 24-h, following intravenous and intramuscular administrations. 

I. Papadoyannis, M. Georgarakis, V. Samanidou, and A. Zotou, Rapid assay for the determination of tolfenamic acid in pharmaceutical preparations and biological fluids by high-performance liquid chromatography, J. Liquid Chromatogr., 74 2951 (1991). 

Tizenidine hydrochloride Tolfenamic acid Toltrazuril Topiramate... 

Shinozuka et al. [91] developed a sensitive method for the determination of four anthranilic acid derivatives (diclofenac sodium, aluminium flufenamate, mefenamic and tolfenamic acids) by HPLC procedure. The four drugs were converted into methylphthalimide (MPI) derivatives in a constant yield by reaction with /V-chloromethylphthalimide at 60°C for 30 min. The production of the MPI derivatives were confirmed by mass spectrometry. The MPI derivatives of the four drugs were separated by HPLC using a C-18 bonded phase LiChrospher RP-18 column (250 x 4 mm i.d.) with acetonitrile-water (80 20, v/v) as mobile phase. The flow rate was 0.8 mL/min. The UV absorbance was measured at 282 nm. The calibration curves of the MPI derivatives of the drugs were linear from 1.0 to 5.0 pg/rnL. The detection limits of the four drugs were 0.5-5 ng. The extraction procedure for the four anthranilic acid derivatives added in the plasma and urine was performed by using Extrelut 1 column. Yields of column extraction of 100 pL of plasma and urine samples (containing 0.5 pg of anthranilic acid derivatives) with 6 mL of ethyl acetate were 84-106%. 

METOCLOPRAMIDE NS AIDS 1. Metodopramide speeds up the onset of action of tolfenamic acid 2. Metodopramide 1 efficacy of ketoprofen Metodopramide promotes gastric emptying 1. Tolfenamic acid reaches its main site of absorption in the small intestine more rapidly 2. Ketoprofen has low solubility and has less time to dissolve in the stomach therefore less ketoprofen is absorbed 1. This interaction can be used beneficially to hasten the onset of analgesia 2. Take ketoprofen at least 2 hours before metodopramide... 

NSAIDs ANTACIDS 1. Magnesium hydroxide T absorption of ibuprofen, flurbiprofen, mefenamic acid and tolfenamic acid 2. Aluminium-containing antacids l absorption of these NSAIDs Uncertain These effects are 1 by taking these drugs with food... 

Disposition in the Body. Readily absorbed after oral administration bioavailability about 60%. It is metabolised by hydroxyla-tion to V-(2-hydroxymethyl-3-chlorophenyl)anthranilic acid and V-(2-methyl-3-chloro-4-hydroxyphenyl)anthranilic acid, which are the major metabolites. About 50% of an oral dose is excreted in the urine in 48 hours mainly as glucuronide conjugates of the two hydroxylated metabolites. Less than 10% of a dose is excreted in the urine as unchanged drug or its glucuronide conjugate. Tolfenamic acid and its metabolites are excreted in the bile. 

Dose. Tolfenamic acid has been given in doses of 300 to 600 mg daily. 

Tolfenamic Acid Meclozine Hydrochloride 228 Azapropazone (anhydrous)... 

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