ISSN:1174-5886    

出版商:ADIS    

年代:2005

数据来源: ADIS

摘要:

Drug-drug interactions continue to be underappreciated and misunderstood by most clinicians. Although life-threatening drug interactions are rare, serious clinical consequences, including altered drug response, poor tolerability with reduced medication adherence, and increased costs for care tied to the increased complexity of therapy, are fairly commonplace. Drug interactions may be further complicated by genetic differences in metabolic capacity. Patients who routinely require long-term treatment for depression have an increased likelihood of experiencing a drug-drug interaction since they will take over-the-counter and prescription medications for intercurrent and/or co-morbid illness. Antidepressants can be the object of drug interactions when their metabolic pathways are affected by other substances, or they can precipitate interactions by inhibiting enzyme pathways. Clinicians can improve the short- and long-term outcomes of patients with a depressive disorder by considering the possibility of drug-drug interactions both before prescribing a specific antidepressant and while monitoring for response, adverse effects and patient compliance.

ISSN:1174-5886    

出版商:ADIS    

年代:2005

数据来源: ADIS

摘要:

Although oral nonsteroidal anti-inflammatory drugs (NSAIDs) are effective in the treatment of a variety of acute and chronic pain conditions, their use may be associated with serious systemic adverse effects, particularly gastrointestinal disorders. In order to minimise the incidence of systemic events related to such agents, topical NSAIDs have been developed. Topical NSAIDs, applied as gels, creams or sprays, penetrate the skin, subcutaneous fatty tissue and muscle in amounts that are sufficient to exert a therapeutic effect on peripheral and central mechanisms in the absence of high plasma concentrations. Data indicate that topical NSAIDs are effective at relieving pain in a number of acute and chronic pain indications.This review article discusses the pharmacokinetics, efficacy and tolerability of a new formulation of ketoprofen available as a topical patch. The topical patch containing ketoprofen 100mg as the active principle has been developed using a novel delivery system that dispenses therapeutic doses of the drug directly to the site of injury.Pharmacokinetic data indicate that although plasma levels of ketoprofen are higher when the drug is administered as a patch versus a gel, the total systemic bioavailability of ketoprofen 100mg administered via a patch is no more than 10% of that reported for ketoprofen 100mg administered orally. Because the patch facilitates ketoprofen delivery over a 24-hour period, the drug remains continually present in the tissue subjacent to the site of application. High tissue but low plasma ketoprofen concentrations mean that while tissue concentrations are high enough to exert a therapeutic effect, plasma concentrations remain low enough to not result in systemic adverse events caused by elevated serum NSAID levels. Phase III clinical trials in patients with non-articular rheumatism and traumatic painful soft tissue injuries showed that the topical ketoprofen patch was significantly more effective than placebo at reducing pain during daily activities and spontaneous pain after 7 days’ treatment. Moreover, the topical ketoprofen patch was well tolerated; adverse events were primarily cutaneous in nature and occurred in a similar number of ketoprofen and placebo recipients suggesting that these events were related to the patch itself rather than the active ingredient. The incidence of gastrointestinal adverse events was low (<8% of all patients), and occurred in a similar proportion of patients receiving ketoprofen and placebo.Thus, the topical ketoprofen patch appears to be a simple, effective and safe therapeutic option for the treatment of local painful inflammation.

ISSN:1174-5886    

出版商:ADIS    

年代:2005

数据来源: ADIS

摘要:

Morphological and biophysical techniques described in this study have shown that membrane derangement occurs in human cataractous lenses. The data suggest that these disruptions were globules, vacuoles, multilamellar membranes and clusters of highly undulating membranes. Deleterious structural damage of the lens fibre cell plasma membranes serve as the primary light-scattering centres that cause the observed lens opacity. Nuclear cataract, a major cause of loss of lens transparency in the aging human, has been thought to be associated with oxidative damage, particularly at the site of the nuclear plasma membrane. Phospholipid molecules modified by oxygen accumulate in the lipid bilayer, change its geo- metry and impair lipid-lipid and protein-lipid interactions in lenticular fibre membranes. Lipid peroxidation (LPO) is a causative and pathogenic factor in cataract. Increased concentrations of primary molecular LPO products (diene conjugates, lipid hydroperoxides, oxy-derivatives of phospholipid fatty acids) and end-fluorescent LPO products have been detected in the lipid moieties of aqueous humour samples and human lenses obtained from patients with senile and complicated cataracts as compared with normal donors.In the present study, a rapid and simple high-performance liquid chromatographic (HPLC) assay for determination of imidazole-containing dipeptides in the aqueous humour of the eye was developed. The method was applied to determine the pharmacokinetic parameters and the time-course of N-acetylcarnosine and L-carnosine-related product in the eye, following a single dosage of topical ocular administration of peptide. Utilising data from pharmacokinetic studies and the specific purity of the N-acetylcarnosine (NAC) ingredient as a source of the pharmacological principle L-carnosine, we have created an ophthalmic time- release prodrug form including the US FDA-approved carboxymethylcellulose lubricant and other essential ingredients (Can-C™, private label Nu-Eyes™). This formulation increases the intraocular absorption of L-carnosine in the aqueous humour and optimises its specific antioxidant activityin vivowhile reducing the toxic effects of lipid peroxides on the crystalline lens. L-carnosine that enters the aqueous humour can accumulate in the lens tissue for a reasonable period of time. The presence of L-carnosine in transparent crystalline lenses during normal aging was detected and its concentration in this case was about 25µM. At different stages of cataract development, the level of L-carnosine drastically decreased, reaching about 5µM in ripe human cataracts. However, administration of pure L-carnosine (1% solution) to the rabbit eye (instillation or subconjunctival injection) does not lead to accumulation of this natural compound in the aqueous humour at the time level over 30 minutes at a concentration exceeding that in placebo-treated matched eyes, and its effective concentration is exhausted more rapidly.Use of NAC prodrug eye drops optimises the clinical effects of L-carnosine in the treatment of ophthalmic disorders (such as prevention and reversal of cataracts in human and animal [canine] eyes). The data provided predict a clinical effect with NAC ophthalmic prodrug, and show that the magnitude and duration of this effect are directly related to the bioavailability of L-carnosine released from NAC in the aqueous humour of the anterior eye segment. The ophthalmic NAC drug shows promise in the treatment of a range of ophthalmic disorders that have a component of oxidative stress in their pathogenesis (including cataract, glaucoma, dry eye, vitreous floaters, inflammatory disorders, and corneal, retinal and systemic diseases [such as diabetes mellitus and its ophthalmic complications]). There is a need for further and better collaboration between Innovative Vision Products' cataract control and ophthalmic services, improved education of people affected by cataract, a commitment that N-acetylcarnosine eye drops will be the preferred treatment before orthodox cataract surgery is attempted, and consideration of outcomes and a possible role of the NAC drug cataract treatment as source of referral for orthodox surgical, ophthalmic and optometric services.

ISSN:1174-5886    

出版商:ADIS    

年代:2005

数据来源: ADIS

摘要:

ObjectiveThis study aimed to establish the receptor selectivity and antihistaminic activity of bilastine, a new selective antihistamine receptor antagonist.Design and methodsIn vitroexperiments were conducted using a receptor binding screening panel and guinea-pig and rat tissues. Antihistaminic activity was determined using H1receptor binding studies andin vitroH1antagonism studies conducted in guinea-pig tissues and human cell lines. Receptor selectivity was established using a receptor binding screening panel and a receptor antagonism screening conducted in guinea-pig, rat and rabbit tissues. Inhibition of inflammatory mediators was determined through the Schultz-Dale reaction in sensitised guinea-pig ileum.ResultsBilastine binds to histamine H1-receptors as indicated by its displacement of [3H]-pyrilamine from H1-receptors expressed in guinea-pig cerebellum and human embryonic kidney (HEK) cell lines. The studies conducted on guinea- pig smooth muscle demonstrated the capability of bilastine to antagonise H1-receptors. Bilastine is selective for histamine H1-receptors as shown in receptor-binding screening conducted to determine the binding capacity of bilastine to 30 different receptors. The specificity of its H1-receptor antagonistic activity was also demonstrated in a series ofin vitroexperiments conducted on guinea-pig and rat tissues. The results of these studies confirmed the lack of significant antagonism against serotonin, bradykinin, leukotriene D4, calcium, muscarinic M3-receptors, α1-adrenoceptors, β2-adrenoceptors, and H2- and H3- receptors. The results of thein vitroSchultz-Dale reaction demonstrated that bilastine also has anti-inflammatory activity.ConclusionsThese preclinical studies provide evidence that bilastine has H1- antihistamine activity, with high specificity for H1-receptors, and poor or no affinity for other receptors. Bilastine has also been shown to have anti-inflammatory properties.

ISSN:1174-5886    

出版商:ADIS    

年代:2005

数据来源: ADIS

摘要:

ObjectiveTo investigate the effects of mild to moderate hepatic impairment on the pharmacokinetics and pharmacodynamics of landiolol hydrochloride, a new ultra-short-acting β1-adrenergic antagonist.MethodsSix patients with hepatic impairment and six healthy volunteers were enrolled in the open-label, parallel-group study. Landiolol hydrochloride was given intravenously with a 1-minute loading infusion of 0.06 mg/kg/min, followed by a 60-minute infusion of 0.02 mg/kg/min using an automated infusion pump. Venous blood was drawn just before (predose) and 1, 2, 5, 15, 30 and 61 minutes after beginning the continuous intravenous infusion (during infusion); 2, 5, 10 and 30 minutes and 1, 4 and 8 hours after the end of the infusion (after infusion); and 24 hours after beginning the infusion (next day). Urine samples were collected up to 24 hours after beginning the infusion. Before subjects were discharged, an indocyanine green elimination test, clinical laboratory testing, physical examination and recording of ECGs and vital signs were performed.ResultsThe geometric mean maximum plasma concentration and area under the concentration-time curve values for the patients with hepatic impairment were 42% and 44% higher, respectively, than those observed for the healthy volunteers, indicating that hepatic impairment affected the disposition of landiolol hydrochloride. There were no significant changes in the elimination half-life of the drug. There were no clinically significant differences between the two groups in terms of reductions in heart rate or blood pressure.ConclusionThe pharmacokinetic and pharmacodynamic characteristics of this ultra-short-acting β1-blocker were maintained even in the patients with hepatic impairment. Although we did not observe any drug-related adverse events in these patients, hypotension or bradycardia should be considered, necessitating continuous monitoring of both heart rate and BP in patients with hepatic impairment who receive landiolol hydrochloride.

ISSN:1174-5886    

出版商:ADIS    

年代:2005

数据来源: ADIS

摘要:

ObjectiveThis study evaluated the influence of simultaneous administration of silymarin (SIL), a hepatoprotective and antioxidant agent, on the status of glutathione (GSH) and its metabolising enzymes in the liver tissue of rats treated with antitubercular drugs, i.e. isoniazid (INH), rifampicin (RIF) and pyrazinamide (PYR).MethodsMale Wistar albino rats (n = 24) were randomly divided into four groups. Group I received saline as they served as controls. Group II rats were administered antitubercular drugs (INH 25mg/kg + RIF 50mg/kg + PYR 140 mg/kg orally) daily for 45 days. Group III animals were treated with SIL (50 mg/kg orally) simultaneously with the antitubercular drugs for the same period. Group IV animals were treated with SIL alone. The status of GSH, glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione-s-transferase (GST) in liver tissue was evaluated at the end of the study.ResultsAdministration of antitubercular drugs caused a significant decrease (p < 0.001) in the status of GPx, GST and GR and of non-enzymic (GSH) antioxidants in liver tissue when compared with saline-treated control rats. Simultaneous treatment of SIL with antitubercular drugs completely prevented decreases in the levels of all the above parameters. Treatment with SIL alone enhanced the activities of GST (p < 0.001) and GPx (p < 0.05) and did not alter glutathione levels compared with control.ConclusionA fall in the status of glutathione and its conjugating enzymes upon administration of antitubercular drugs denotes an impairment of the antioxidant defence mechanism. Simultaneous administration of SIL afforded complete protection of the liver against this abnormality, an effect that could have been due to the strong antioxidant properties of SIL.

ISSN:1174-5886    

出版商:ADIS    

年代:2005

数据来源: ADIS