Voltammetric determination of montelukast sodium in dosage forms and human plasma.

Belal F.

Department of Pharmaceutics, Faculty of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia.

The voltammetric behaviour of montelukast (MKST) was studied using cyclic voltammetry, direct current (DC(t)), differential pulse polarography (DPP) and alternating current (AC(t)) polarography. MKST exhibited well-defined cathodic waves over the range pH range 1-5. No anodic waves were produced over the same pH range. At pH 1, the analytical pH; the diffusion current constant (Id) was 2.2+/-0.01 muA l mmol(-1). The current concentration plot was rectilinear over the range 2-20 mug ml(-1) with correlation coefficient (n=10) of 0.9943. The lower limit of detection (S/N = 2) was 0.2 mug ml(-1) (3.41x10(-7) M). The wave has been characterised as being diffusion-controlled, although adsorption phenomenon played a limited role in the electrode reaction. The proposed method was successfully applied to the determination of MKST in commercial tablets, and results were in agreement with those given with a reference HPLC method. The method was further extended to the in vitro determination of the drug in spiked human plasma. The mean % recovery (n=5) was 101.38+/-3.85. The number of electrons transferred in the reduction process could be accomplished and a proposal of the electrode reaction was proposed.

Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15925367&dopt=Abstract montelukast, Singulair




Role of Leukotriene Inhibitors in the Postoperative Management of Nasal Polyps.

Yamani M.

Department of Otorhinolaryngology Ain-Shams, Benha Universities, Cairo, Egypt.

This was a prospective double blind comparative study on 40 patients. It compared the effects of the leukotriene receptor antagonist montelukast and beclomethasone nasal spray on the post-operative course of patients with sinonasal polyps. All patients underwent endoscopic sphenoethmoidectomy and were randomized post-operatively into two groups. Group I: 20 patients (9 females and 11 males) age 17 to 67 (32.4 +/- 9.5 years), receiving 10 mg montelukast orally daily and Group II: 20 patients (6 females and 14 males) age 17 years to 57 years (33.5 +/- 11.9 years), receiving 400 ug beclomethasone local sprays daily. All patients were followed up for 1 year and a symptom score was recorded throughout this period. There was a significant reduction in symptom scores in both groups throughout the study period. In the montelukast group improvement was more marked in itching, post-nasal discharge and headache. The control of sneezing and rhinorrhea was comparable in both groups with a marginal advantage of montelukast. Steroids had a more marked effect on smell disturbances and obstruction. There was no difference in the recurrence rate or in the need for rescue medications between both groups. Both drugs seem to have a complementary action and further studies are needed to determine which patients should receive which treatment. Copyright (c) 2005 S. Karger AG, Basel.

Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15925911&dopt=Abstract montelukast, Singulair




Differential effect of zileuton, a 5-lipoxygenase inhibitor, against nociceptive paradigms in mice and rats.

Kulkarni SK.

Pharmacology Division, University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh 160 014, India.

Pain is commonly associated with inflammation. Several mediators including prostaglandins have been implicated in pain and inflammation. However, the recent reports indicated the role of leukotrienes as signaling molecules in pain. The present study was aimed to evaluate the effect of 5-LOX inhibitor, zileuton in nociceptive paradigms including inflammatory pain. Acetic acid-induced writhing, tail flick and hot plate tests to assess pain response were used. The effect on carrageenan-induced mechanical hyperalgesia, and acetic acid-induced vascular permeability was also determined. Zileuton (ED(50)=31.81 mg/kg p.o.), zafirlukast (ED(50)=6.19 mg/kg p.o.), montelukast (ED(50)=7.17 mg/kg p.o.) inhibited acetic acid-induced writhing in mice. Further, zileuton and ZK 158252, leukotriene B(4) receptor antagonist did not alter basal response against tail flick and hot plate assays. Acetic acid-induced vascular permeability was significantly inhibited by zileuton. Oral administration of zileuton showed efficacy against carrageenan-induced mechanical hyperalgesia and also reversed histological changes in paw biopsies. These data suggest that zileuton, a 5-LOX inhibitor, exhibited antinociceptive effect in paradigms of inflammatory pain.

Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15935457&dopt=Abstract montelukast, Singulair




Leukotriene receptor blocker montelukast protects against burn-induced oxidative injury of the skin and remote organs.

Yegen BC.

School of Pharmacy, Department of Pharmacology, Marmara University, 34668 Haydarpasa, Istanbul, Turkey.

Thermal injury elicits several systemic consequences, among them the systemic inflammatory response where the generation of reactive oxygen radicals and lipid peroxidation play important roles. In the present study, we investigated whether the leukotriene receptor blocker montelukast is protective against burn-induced remote organ injury. Under brief ether anaesthesia, shaved dorsum of the rats was exposed to 90 degrees C (burn group) or 25 degrees C (control group) water bath for 10s. Montelukast (10mg/kg) or saline was administered intraperitoneally immediately after and at the 12th hour of the burn injury. Rats were decapitated 24h after burn injury and the tissue samples from lung, liver, kidney and skin were taken for the determination of malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity and collagen contents. Tissues were also examined microscopically. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) levels and creatinine, urea (BUN) concentrations were determined to assess liver and kidney function, respectively. Tumor necrosis factor-alpha (TNF-alpha) and lactate dehydrogenase (LDH) were also assayed in serum samples. Severe skin scald injury (30% of total body surface area) caused a significant decrease in GSH level, which was accompanied with significant increases in MDA level, MPO activity and collagen content of tissues. Similarly, serum ALT, AST and BUN levels, as well as LDH and TNF-alpha, were elevated in the burn group as compared to control group. On the other hand, montelukast treatment reversed all these biochemical indices, as well as histopathological alterations, which were induced by thermal trauma. Findings of the present study suggest that montelukast possesses an anti-inflammatory effect on burn-induced damage in remote organs and protects against oxidative organ damage by a neutrophil-dependent mechanism.

Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15935562&dopt=Abstract montelukast, Singulair




The effect of montelukast and different doses of budesonide on IgE serum levels and clinical parameters in children with newly diagnosed asthma.

Kuna P.

The M Curie Hospital, Department of Pediatrics and Allergy, Zgierz, Poland.

BACKGROUND: Since IgE is considered to play a crucial role in allergic immune responses, the reduction of free IgE level has been an attractive target in the treatment of allergic diseases. The present study was conducted to determine the effects of a 6-month treatment with different doses of inhaled budesonide and montelukast sodium in children with newly diagnosed atopic asthma. METHODS: In this randomized, double-blind, double-dummy trial, 51 children with newly diagnosed asthma and sensitivity to house-dust mites were randomly allocated to receive budesonide (in two different doses 400 or 800mcg) or montelukast for 6 months. The primary end point was the level of serum total and specific IgE before and after treatment. The secondary end points were clinical parameters and forced expiratory volume in 1s (FEV1). RESULTS: After 6 months of treatment, a high dose of inhaled corticosteroid and montelukast, significantly decreased levels of total and specific IgE. Medium dose of inhaled corticosteroid had no effect on total and specific IgE serum level. Clinical score and FEV1 significantly improved after 6 months of treatment with medium (P=0.002) and high dose (P=0.001) of inhaled budesonide and montelukast (P=0.002). There were no differences between groups in changes of all clinical parameters after treatment. CONCLUSION: Only high doses of inhaled corticosteroids and montelukast decreased the serum IgE levels. Perhaps long-term treatment with montelukast will be beneficial to asthma patients by decreasing IgE levels.

Online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15939317&dopt=Abstract montelukast, Singulair