New Treatment for COPD Bared

Studies show tiotropium reduces exacerbations, improves quality of life

Chronic obstructive pulmonary disease (COPD) is a slowly progressive respiratory disorder characterized by chronic airflow limitation, shortness of breath (dyspnea), frequent morning cough, and increased sputum production. This loss of lung function is a major cause of disability and death.

    The World Health Organization estimates that 600 million people suffer from COPD worldwide. In the Philippines, between five to six percent of the population, aged 30 and above--about two million Filipinos, have moderate to severe COPD.

    According to the guidelines developed by the Global Initiative for Chronic Obstructive Lung Disease (GOLD), the key element in treatment is the avoidance of risk factors, of which smoking tops the list. About 10 to 15 percent of smokers develop COPD, while death rates from emphysema and chronic bronchitis (the two components of COPD) are highest among smokers.

    As well as to prevent disease progression, GOLD emphasizes the symptomatic management of COPD. Although the destruction of the alveolar walls is irreversible, improving the smooth muscle tone of the small airways can mitigate airflow obstruction. Improvement in the exchange of oxygen and carbon dioxide between the alveoli and the blood thus follows.

    Bronchodilators used in the management of COPD, however, have different mechanisms of action. Tiotropium (Spiriva), a once daily inhaled compound, acts on the parasympathetic nervous system, by blocking the neurotransmitter, acetylcholine, from binding to the cholinergic receptors (particularly the M3 receptor) responsible for bronchoconstriction.

    Tiotropium has been subject to an extensive pre-clinical and clinical development program, which included one of the largest pre-registration safety databases in COPD patients. Studies on safety and efficacy were conducted in over 1,300 patients with COPD.

    Notable clinical trial findings were improved health outcomes in patients with COPD during one-year treatment with tiotropium. In a study published in the European Respiratory Journal this year, the efficacy of tiotropium was compared with ipratropium bromide. The results are as follows:

• As measured by the St. George's Respiratory Questionnaire, more patients in the tiotropium group achieved significantly improved health related quality of life after one year versus those in the ipratropium bromide group.

• Tiotropium significantly reduced the frequency of exacerbations by 24 percent over one year compared to ipratropium bromide.

• Patients given tiotropium had a decreased use of short acting beta-agonists versus those given ipratropium.

    Clinical trials also demonstrated that maintenance treatment with tiotropium, which provides 24-hour bronchodilation, improved lung function as assessed by measurement of forced expiratory volume in one second prior to morning dosing of medication. Again, the improvement surpassed that observed in ipratropium bromide--approximately 150 ml above.

    Also, treatment with tiotropium resulted in improving the dyspnea in patients with COPD, and has proven safe and well tolerated. Adverse effects were minimal: dry mouth at 14 percent was the most frequently reported, while constipation, moniliasis, sinusitis, and pharyngitis occurred with frequencies within one percent and two percent of placebo. Furthermore, tiotropium is not suitable as an initial treatment of acute episodes of bronchospasm.

    Tiotropium was developed by Boehringer Ingelheim and is being co-promoted internationally with Pfizer Inc. Launched last July 8, tiotropium is the first once-daily inhaled COPD therapy in the Philippines, the first country in Asia to introduce this novel COPD treatment. So far, 16 European countries recognize the tiotropium application.

    Tiotropium is administered using the HandiHaler, a breath-actuated, single-dose dry powder inhaler developed by Boehringer Ingelheim specifically for the administration of tiotropium. The HandiHaler has a wide range of airflow limitations.