Antiasthma drugs inhaled

Patients and physicians need to be aware that although antiasthma drugs inhaled from pMDIs do not usually produce adverse effects, they can make symptoms worse. Paradoxical bronchospasm has been associated with the use of betaj agonists and corticosteroids inhaled from MDIs (56-58). Decreases in FEVj, of more than 10% have been reported to occur in as many as 4.4% of subjects (59). Nick-las (58) reviewed adverse reaction reports submitted to the Center for Drug Evaluation and Research of the FDA between 1974 and 1988 of these, 126 reports associated with the use of these drugs by MDI, which were consistent with the diagnosis of paradoxical bronchospasm, were observed. More recently, Wilkinson et al. (60) reported paradoxical bronchoconstriction in asthmatic patients after inhaling salmeterol by a pMDI but not via a DPI. 

Some irritation of the nasal and upper respiratory passages may occur following inhalation, but these drugs are remarkably free of serious adverse reactions. Hence, cromolyn and nedocromil are often used preferentially to treat mild persistent asthma, especially in children or in individuals who are unable to tolerate the side effects of other antiasthma drugs.102,113... 

R. Pauwels, S. Newman, and L. Borgstrom, Airway deposition and airway effects of antiasthma drugs dehvered from metered-dose inhalers, Eur. Respir. J. 70 2127 (1997). 

A nebulizer is an inhaler that delivers an antiasthma drug in the form of a dry, micronized power directly to the lungs. 

The most important development in antiasthma drug delivery was the advent of the metered-dose inhaler in 1956, which resulted in a huge increase in the use of antiasthma therapy. Sales of pressurized metered-dose inhalers now run at approximately 500 million per year. However, the introduction of this device was not without problems. This section of the chapter covers the early use of propellants in atomization, the origin of the metered-dose inhaler, and the epidemic of asthma deaths. 

The pressurized metered-dose inhaler (pMDI) for the delivery of antiasthma drugs originated in the U.S. cosmetic industry. George Maison, the president of Riker Laboratories, and Irvin Porash, who worked in Riker s pharmaceutical development laboratory, are credited with the development of the first pMDI (32). Experiments were conducted to formulate pressurized aerosols of isoproterenol and epinephrine, which had been dissolved in alcohol, using the freon propellants 12 and 114. 

The pMDI will continue to be one of the most popniar drug delivery devices for inhaled antiasthma drugs. The inaeasing number of modifications to the standard inhaler should improve drug dehvery. 

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