Lornoxicam, a new potent NSAID with an improved tolerability profile.

Lornoxicam is a member of the oxicam group of nonsteroidal antiinflammatory drugs (NSAIDs). Oxicams have potent antiinflammatory and analgesic effects, but their use is associated with a high risk of gastrointestinal adverse effects. Lornoxicam has been shown to be at least as effective as comparative NSAIDs and more effective than 10 mg morphine when used at doses > or = 8 mg to control pain after oral surgery. In addition, oral doses of lornoxicam of 16-24 mg daily have been more effective than tramadol 300 mg daily in pain following knee surgery. Lornoxicam combines the high therapeutic potency of oxicams with an improved gastrointestinal toxicity profile as compared to naproxen, for example. This is probably due to the short half-life of lornoxicam as compared to the other oxicams. The clinical trials published so far, mostly comparative, clearly do- cument the efficacy of lornoxicam as a potent analgesic with excellent antiinflammatory properties in a range of painful and/or inflammatory conditions, including postoperative pain and rheumatoid arthritis.

Absolute bioavailability, pharmacokinetics, renal and biliary clearance of distigmine after a single oral dose in comparison to i.v. administration of 14C-distigmine-bromide in healthy volunteers.

AIM: The aim of the study was to determine the absolute bioavailability and pharmacokinetics after a single dose oral administration in comparison to i.v. administration of 14C-labelled distigmine-bromide (14C-Ubretid) in healthy male volunteers. RESULTS: After the intravenous administration, distigmine is eliminated from the body by renal excretion (85%), and for a small fraction by biliary excretion in the feces (4%). This situation is reversed after an oral administration, where 6.5% of the dose is recovered from the urine and 88% from the feces. This means that distigmine after oral administration is hardly absorbed, the calculated bioavailability is 4.65%. CONCLUSION: The mean absorption time (MAT) after oral administration was 10 h, influencing the t(1/2alpha) (1.4 vs 4.5 h) and the t(1/2beta) (60 vs 70 h) to higher values than after the i.v. administration (p < 0.05).

Pharmacokinetics and metabolism of the proton pump inhibitor pantoprazole in man.

Pantoprazole, a second-generation proton pump inhibitor, is absorbed after oral administration as enteric-coated tablet with maximum plasma concentrations within 2-3 h and a bioavailability of 77%. Food has no relevant effect on absorption. The pharmacokinetics of pantoprazole are dose linear in the therapeutic range. The parent drug is totally metabolized, mainly by the polymorphically expressed CYP2C19 and by CYP3A. The pharmacokinetic profile is practically unchanged after multiple dosing, as is expected for a drug with a short half-life of about 1 h. A lack of pharmacokinetic interactions with various drugs has been shown. No clinically relevant changes in the pharmacokinetics of pantoprazole are observed in elderly subjects and patients with severe renal insufficiency. However, clearance is decreased in poor metabolizers of (S)-mephenytoin and in patients with liver cirrhosis.

Determination of the novel non-steroidal anti-inflammatory drug lornoxicam and its main metabolite in plasma and synovial fluid.

A rapid and sensitive HPLC method for the determination of the non-steroidal anti-inflammatory drug lornoxicam in plasma samples of humans and laboratory animals is described. After addition of the internal standard (tenoxicam) the plasma sample is acidified and extracted either by dichloromethane via Extrelut columns or by solid-phase extraction using C18 columns. After evaporation of the solvent the separation is performed on a C18 column in isocratic mode with a mobile phase consisting of 0.1 M phosphate buffer (pH 6.0)-methanol and detection at 372 nm. The limit of determination was set to 10 ng/ml using 0.5 ml of sample but can be extended down to 2.0 ng/ml plasma. Using solid-phase extraction with C18 columns both lornoxicam and its main metabolite 5'-hydroxylornoxicam can be determined while extraction via Extrelut was used in studies where only lornoxicam was to be determined. This method was used successfully in several thousand samples of pharmacokinetic and bioavailability studies in animals and in humans.

Evaluation of chronic oral toxicity and carcinogenic potential of lornoxicam in rats.

As part of the preclinical development program for lornoxicam, a novel non-steroidal anti-inflammatory drug (NSAID), its chronic oral toxicity and carcinogenic potential was assessed in Sprague-Dawley rats. Male and female rats were administered lornoxicam by oral gavage at 0, 0.06, 0.16 or 0.40 mg/kg/day for 12 months or at 0, 0.01 or 0.06 mg/kg/day in a supplementary low-dose study of the same duration (main group: 20/sex/group; 4-wk recovery: five/sex/group; satellites for electrocardiography and toxicokinetics: five/sex/group). Drug-related toxicity mainly comprised mortality, reduced body weight gain, clinico-pathological changes indicative of anaemia resulting from blood loss, and renal damage, renal papillary necrosis and gastrointestinal mucosal lesions. The kidney-associated changes were not completely reversible during the recovery period. Toxicokinetic investigations demonstrated a dose-linear absorption of the drug. In female rats the terminal half-life was about twice that in males which led to a higher exposure of this gender to lornoxicam. A dose of 0.01 mg/kg/day was established as no-observed-effect level. In a 104-wk carcinogenicity study, lornoxicam was administered by oral gavage to male and female rats (50/sex/group) at 0 (control 1), 0 (control 2), 0.0625, 0.125 or 0.250 mg/kg/day. In females only, the high dose was reduced twice during the study due to toxicity observed (0.250 to 0.200 to 0.160 mg/kg/day). Drug-related changes were similar to those in the chronic studies and consistent with the anticipated side-effects of NSAIDs. No carcinogenic potential was revealed.

Subacute and chronic oral toxicity of lornoxicam in cynomolgus monkeys.

Lornoxicam is a novel non-steroidal anti-inflammatory compound in the same chemical class as piroxicam and tenoxicam, with potent anti-inflammatory, antipyretic and analgesic activity. As part of the preclinical safety programme, its toxicity was evaluated in a dose-range-finding and 52-wk toxicity study in cynomolgus monkeys. In the dose-range-finding study, five groups of monkeys (two per sex per group) were dosed orally by gavage for 6 wk with 0, 0.25, 0.5, 1.0 or 2.0 mg lornoxicam/kg/day. Drug-related toxicity was observed in the 1.0 and 2.0 mg/kg/day dose groups only. This included mortality, diarrhoea, prostration, decreased body weight gain and food consumption, faecal occult blood, anaemia, leucocytosis, hypoalbuminaemia, gastrointestinal erosions and ulcerations. On the basis of these results, four groups of monkeys (six per sex per group) were given the compound orally by nasogastric intubation at dose levels of 0, 0.125, 0.25 or 0.5 mg/kg/day for 52 wk. The high-dose level was increased to 0.6 mg/kg/day from wk 39 to wk 52. Treatment was followed by a 4-wk recovery period for two animals per sex per group. Histologically, drug-related changes seen were gastrointestinal erosions, ulcerations and inflammation in males and females at 0.5/0.6 mg/kg/day. Treatment-related clinicopathological findings included decreased haematocrit and hypoproteinaemia (group 0.5/0.6 mg/kg/day males), and hypoalbuminaemia (group 0.5/0.6 mg/kg/day males and females). None of these changes were present after the recovery period, thus indicating reversibility. Plasma concentration of lornoxicam measured 2 hr after dosing increased in a dose proportional manner. The estimated area under the curve (AUC) at steady state increased in a dose-proportional manner and at 0.25 mg/kg was three- to fivefold higher than the human AUC following a 16 mg dose (8 mg b.i.d.). The no-observed-effect level in the chronic toxicity study was 0.25 mg/kg/day.

Overview of the pharmacological properties, pharmacokinetics and animal safety assessment of lornoxicam.

Lornoxicam is a new, highly potent antirheumatic agent which is an oxicam derivative. Although highly potent as a cyclo-oxygenase inhibitor, the compound does not cause inhibition of 5-lipoxygenase and does not appear to shunt arachidonic acid through this cascade. This powerful inhibition of cyclo-oxygenase has manifested itself as highly potent analgesic and anti-inflammatory effects in animal studies and also prevented the bone destruction which normally occurs in the adjuvant polyarthritic rat. To explain this finding, studies have demonstrated that lornoxicam inhibits polymorphonuclear (PMN)-leukocyte migration; inhibits the release of superoxide from human PMN-leukocytes; inhibits the release of platelet derived growth factor (PDGF) from human platelets and stimulates the synthesis of proteoglycans in cartilage in tissue culture. Lornoxicam is well absorbed and has a plasma t1/2 in man of 4 hours which is distinctly different from other oxicams. It is metabolized in animals and in man to the 5'-hydroxy-metabolite which is inactive in pharmacological tests. In vitro and in vivo animal safety studies have demonstrated both subchronically and chronically that lornoxicam manifests no unusual toxicity, is not a mutagen nor is it tumorigenic and causes no fetal teratogenicity in reproduction studies.

Pharmacokinetics of lornoxicam in man.

Clinical phase I pharmacokinetic studies with lornoxicam were performed with the 4 mg dose of lornoxicam. Lornoxicam was administered as an aqueous solution both orally and intravenously to young, healthy, male volunteers. The total excretion of lornoxicam via urine and faeces after oral administration was determined by administering 14C-labelled compound. The results show that the parent compound and the main metabolite, 5'-hydroxy-lornoxicam, were found in plasma. However, in urine, no lornoxicam was detected, only 5'-hydroxy-lornoxicam. After oral as well as intravenous administration, a short terminal half-life of lornoxicam in the range of 4-5 hours was found. Given orally as solution, lornoxicam was rapidly and almost completely absorbed.

The effect of concomitantly administered antacids on the bioavailability of lornoxicam, a novel highly potent NSAID.

Antacids are used in the treatment of upper gastrointestinal side-effects during therapy with nonsteroidal anti-inflammatory drugs (NSAIDs). Since pharmacokinetic interactions between antacids and NSAIDs have been reported, it was investigated whether aluminium and magnesium hydroxide (Maalox as oral suspension) or aluminium hydroxide and calcium carbonate (Solugastril as oral gel) influenced the bioavailability of Lornoxicam (rINN), a new potent NSAID from the chemical group of the oxicams. Eighteen male volunteers were given 4 mg of Lornoxicam as a film-coated tablet either alone or together with 10 ml of Maalox or 10 g of Solugastril in an open, randomized, three-way cross-over study. The levels of Lornoxicam in plasma were determined by HPLC following solid-phase extraction. It was found that none of the antacids changed significantly any of the following pharmacokinetic parameters: elimination half-life (t1/2 beta), concentration at peak time (Cmax), time to reach the peak (tmax) and area under the curve to infinity (AUCo-infinity). The results indicate that the concomitant administration of antacids did not influence the pharmacokinetic profile of Lornoxicam. Furthermore they confirm the short elimination half-life of Lornoxicam in man, which is markedly shorter than that of other oxicam-type compounds.