Gastrointestinal blood loss induced by three different non-steroidal anti-inflammatory drugs

A clinical study was performed on 18 healthy volunteers to compare the gastrointestinal daily blood loss induced by oral intake of three different non-steroidal anti-inflammatory drugs, lysine clonixinate (CAS 55837-30-4), ibuprofen (CAS 15687-27-1) and acetylsalicylic acid (CAS 50-78-2 ASA). For quantitative determination of gastrointestinal blood loss, autologous erythrocytes were radiolabelled in vitro with 51Cr and reinfused at study start. The amount of radioactivity excreted in faeces was measured during a placebo baseline phase of three days, a treatment phase of five days with thrice daily dosing of ASA, ibuprofen or lysine clonixinate and a subsequent wash-out phase of five days. The highest increase of mean daily blood loss over baseline was observed after treatment with ASA (+ 1.66 ml/d versus baseline). Treatment with ibuprofen led to an increase of mean daily blood loss by + 0.52 ml/d. During treatment with lysine clonixinate the mean increase of daily blood loss was +0.32 ml/d versus baseline. In the ibuprofen and lysine clonixinate treatment groups the values of mean daily blood loss decreased during the wash-out phase with respect to the verum phase, whereas the mean daily blood loss during the wash-out phase after treatment with ASA even increased in comparison to the verum phase (mean daily blood loss: +2.07 ml/d versus baseline.

Flunixin in the cat: a pharmacodynamic, pharmacokinetic and toxicological study

There are relatively few non-steroidal anti-inflammatory drugs (NSAIDs) for which basic pharmacokinetic and toxicological data are available in the cat. This paper describes some pharmacokinetics and pharmacodynamics of flunixin in this species. Six healthy adult female cats were given 1.0 mg kg-1 flunixin meglumine orally daily for 7 consecutive days. Indwelling catheters were placed on the day preceding the first and last flunixin doses and 2 ml blood samples were taken for flunixin and thromboxane B2 (TXB2) assay before dosing and at 1, 2, 3, 5, 7, and 24 h after the first and the last doses of flunixin. Blood samples for haematology were taken before any treatment had been given and on treatment days 4 and 7 as well as 7 days after the end of treatment. On the first day of dosing, Cmax ranged from 0.45-6.94 micrograms ml-1 flunixin and the mean plasma concentration was greatest at 1 h (2.46 micrograms ml-1). No flunixin was detected by 24 h. After 7 days dosing, Cmax ranged from 0.47-2.46 micrograms ml-1. The mean plasma concentration was again greatest at 1 h but was lower (1.68 micrograms ml-1) than on the first day of treatment. No flunixin was detected beyond 5 h after dosing. The area under the plasma concentration time curve 0-24 h on the first day was 6.82 +/- 1.85 micrograms ml-1h-1 and 3.32 +/- 0.73 micrograms ml-1h-1 on the seventh day. On the first treatment day, serum TXB2 was inhibited by at least 75% in all post-treatment samples up to 7 h but on the seventh day it was reduced only at 1 and 2 h after dosing. Serum TXB2 was significantly higher on the seventh treatment day compared with the first at 3, 5 and 7 h after dosing. No abnormal clinical signs were seen and appetite was unaffected throughout the study. Most biochemical and haematological values remained within normal limits although alanine aminotransferase increased from 11.4-21.3 iu l-1 on day 7 without any other evidence of abnormality. The data suggest that the cats developed tolerance to flunixin although it is not known whether this was due to liver enzyme induction or reduced drug absorption. It is interesting that the cat, despite its reputation for inability to eliminate NSAIDs, has a relatively short flunixin half life and appears to develop tolerance to the drug.

Comparison of adverse effects of phenylbutazone, flunixin meglumine, and ketoprofen in horses

The relative toxicity of phenylbutazone, flunixin meglumine, and ketoprofen was studied in healthy adult horses. Sixteen horses were randomly assigned to receive 10 ml of physiologic saline solution, or ketoprofen (2.2 mg/kg of body weight), flunixin meglumine (1.1 mg/kg), or phenylbutazone (4.4 mg/kg) IV, every 8 hours, for 12 days. Results of CBC, serum biochemical analyses, and fecal occult blood tests were monitored. On day 13, all horses were euthanatized and complete necropsy examinations were performed. Mean CBC values remained within normal limits for all groups. Phenylbutazone-treated horses had a significant (P < 0.05) decrease in serum total protein and albumin concentrations. Mean values of all other serum biochemical assays were not different from those of the saline-treated group. Results of all fecal occult blood tests were negative. At necropsy, the glandular portion of the stomach was the area of the gastrointestinal tract most severely affected by phenylbutazone, flunixin meglumine, and ketoprofen. In the phenylbutazone-treated group, but not in the other groups, edema of the small intestine and erosions and ulcers of the large colon were observed. None of the horses treated with saline solution had lesions in the glandular portion of the stomach or in the intestine. Four horses (1/5 and 3/3 in the flunixin- and phenylbutazone-treated groups, respectively) developed renal crest necrosis. Horses in the saline- and ketoprofen-treated groups did not develop renal lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical and pathological effects of flunixin meglumine administration to neonatal foals

The effects of daily intravenous administration of flunixin meglumine at dosages of 0.55, 1.1, 2.2 and 6.6 mg/kg for five days were examined in neonatal foals. Six two day old foals were used to evaluate the effect of each dosage. Foals were examined every day and blood samples collected on days 1, 3 and 6. All foals were euthanized after six days, necropsied and examined for lesions. The major clinical abnormality was diarrhea, but the incidence was not related to the dosage of flunixin meglumine administered. The foals receiving 6.6 mg/kg of flunixin meglumine had significantly more gastrointestinal ulceration and greater cecal pathology and cecal petechiation scores than those foals treated with saline. The foals in the 6.6 mg/kg treatment group had a greater loss of total protein during the study, but the difference was not significant. There were no statistically significant blood cellular or biochemical alterations associated with the administration of flunixin meglumine. There were no significant clinicopathological differences between healthy foals treated with the recommended dosage of flunixin meglumine and those treated with physiological saline.

Analgesic action of clonixin, nifedipine and morphine using the formalin test

1. The analgesic effect of ClX, nifedipine, metamizol, indoprofen and morphine in the pain induced by formalin injection (formalin test) was studied. 2. Attempts to demonstrate tolerance to ClX were unsuccessful. 3. In the analgesic test nifedipine and morphine are approximately 10 times more potent than ClX. 4. The present results suggest that the analgesic action of ClX is not mediated by mu 1, delta or kappa-opioid receptors and the anti-nociceptive effect of nifedipine may be associated with the blockade of the transmembrane inward movements of calcium.

Chronic flunixin meglumine therapy in foals

Effects of a therapeutic dose of flunixin meglumine on gastric mucosa of horse foals were determined by endoscopy, double-contrast radiography, and gross and histologic examinations. Foals were administered 1.1 mg of flunixin meglumine/kg of body weight, PO/day for 30 days in an encapsulated form that was divided into 2 doses/day (group 1; n = 3) or by IM injection once a day (group 2; n = 7). Three control foals (group 3; n = 3) were administered capsules (n = 1) containing dextrose powder or IM injections (n = 2) of vehicle solution without flunixin meglumine. All 3 groups-1 foals given flunixin meglumine PO developed oral ulcers. Group-2 foals given flunixin meglumine IM did not develop oral ulcers. One control foal (group 3) developed 1 oral ulcer that healed during the study. Endoscopic examination revealed linear crease-like mucosal lesions in the glandular portion of the stomach in 2 group-2 foals. Radiographic evidence of gastric ulcers was observed in only 1 gastrogram of a group-1 foal. Foals were euthanatized, and necropsy revealed erosions and/or ulcers of the glandular portion of the stomach. Oral ulcers were observed in all 3 group-1 foals. Erosions of the glandular portion of the stomach developed in all 10 foals given flunixin meglumine, but did not develop in group-3 foals. Ulceration of the glandular portion of the stomach was present in 1 group-2 foal.