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| |  FDA Approves Xopenex For Bronchospasm Treatment MARLBOROUGH, MA -- March 26, 1999 -- The United States Food and Drug Administration has approved Sepracor Inc.’s Xopenex(TM) (levalbuterol HCl) inhalation solution in two dosage strengths for use with a nebulizer for the treatment and prevention of bronchospasm. Xopenex is the therapeutically-active (R)-isomer of racemic albuterol. Racemic albuterol, an equal mixture of (R) and (S) isomers, is the world's leading bronchodilator for asthma. In Sepracor's clinical trials, Xopenex demonstrated excellent safety and efficacy and a duration of action that lasted up to eight hours. "It appears the removal of the unnecessary (S)-isomer results in a purer and more potent drug," said Harold Nelson, M.D., senior staff physician in the department of medicine at National Jewish Medical and Research Center and lead investigator in Xopenex Phase III clinical trials. "For reasons that have not yet been clarified, the (S)-isomer when exposed to the patient in racemic form has been shown to interfere with the overall efficacy of the (R)-isomer." In a Phase III, 362-patient four-week pivotal study, patients treated with 0.63 mg of Xopenex demonstrated lung-function responses comparable to those treated with the standard clinical dose (2.5 mg) of racemic albuterol, after the first dose as well as after four weeks of therapy. Generally patients on 0.63 mg of Xopenex reported a lower incidence and severity of beta-mediated side effects, such as nervousness and tremor, compared with those taking 2.5 mg of racemic albuterol. Efficacy, as measured by the mean percent change from baseline in FEV1, was demonstrated for all active treatment regimens compared with placebo on day one and day 29. On both day one and day 29, 1.25 mg of Xopenex demonstrated the largest mean percent change from baseline in FEV1 compared to the other active treatments. "With the prevalence of asthma, especially in children, on the rise, there is a great need for rescue therapy with minimal side effects," said Jeffrey Drazen, M.D., professor of medicine, Harvard Medical School. "Levalbuterol is the first real advance in rescue asthma therapy in over 20 years." The first indication for Xopenex will be for the relief and prevention of bronchospasm. The drug will be available in solution formulation used in nebulizers. This device is an electric air compressor with a mouthpiece through which the patient breathes vaporised asthma medication. Children and elderly patients with severe asthma or those who have difficulty using other drug delivery systems, primarily use nebulizers. Reflecting the increasing incidence of asthma among children, the nebulizer segment continues to grow. Asthma is a chronic disorder of the bronchial airways. During an asthma attack, the bronchial airways become narrowed as the bronchial muscles tighten. Bronchodilators, also known as beta-agonists, are used as primary treatment for acute and chronic asthma attacks because of their immediate onset of action. In order to treat asthma effectively, beta agonists should be used in conjunction with the long-term therapy of either steroids and/or leukotriene antagonists. According to the American Lung Association, the number of deaths attributed to asthma has increased 117 percent since 1979. More than 14.6 million Americans suffer from asthma, which is the sixth-ranking chronic condition in America. Asthma accounts for an estimated three million lost work days annually for people over 18 years of age; the annual direct health care costs of asthma is approximately $9.8 billion US; indirect costs, such as lost productivity, add another $2.8 billion US. Side effects from Xopenex, like other beta-agonists, may include dizziness, nervousness, tremor and dyspepsia. Patients with cardiovascular and convulsive disorders should use caution when administering the drug. Hundreds of drugs on the market today are racemic mixtures with equal amounts of two isomers, an (R)-isomer and an (S)-isomer. In racemic albuterol, the (R)-isomer is exclusively responsible for the therapeutic effect and perfectly matches the human body's receptor. The (S)-isomer has been found to have no therapeutic benefit and poorly matches the body's receptor. Scientific data have suggested the (S)-isomer may cause detrimental airway hyperactivity. Xopenex is the optically pure (R)-isomer version of racemic albuterol.
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