:: Section 6
What hazards are associated with aerosol drug therapy?
While aerosol therapy has provided a means to treating many diseases, we need to be aware of the possible hazards associated with it so that the adverse effects can be prevented. The primary hazard of aerosol drug therapy is an adverse reaction to the medication being administered. Testing should be done prior the aerosol therapy to ensure the patent will not develop a reaction. Other hazards include infection, airway reactivity, systemic effects of bland aerosols, and drug reconcentration.
- Aerosol generators can contribute to nosocomial infections by spreading bacteria by the airborne route. The most common sources of bacteria are contaminated solutions (i.e., multiple-dose drug vials), caregivers’s hands, and the patient’s own secretions. Offending organisms are primarily gram-negative bacilli, particularly Pseudomonas aeruginosa and Legionella pneumophila (the cause of the highly virulent legionnaires’ disease)
- Airway reactivity may result from the cold and high-density aerosol. It can cause reactive bronchospasm and increased airway resistance, especially in patients with preexisting respiratory disease. Medications such as acetylcystine, antibiotics, steroids, cromolyn sodium and ribavirin have been associated with increased airway resistance and wheezing during aerosol therapy. Even distilled water has also been reported for some patients.
Pulmonary and systemic effects
- The deposition site and the properties of the medicine are the key parameters in determining pulmonary and systemic effects. However, it should be noted that even bland aerosols present risk. Too much water can cause overhydration, while excess saline solution can cause hypernatremia. Data from animal experiments have shown that long-term, continuous administration can cause tissue damage, atelectasis, and pulmonary edema.
- During nebulization, drug solution undergoes evaporation, heating, baffling, and recycling. As a consequence, solute concentration may increase. The patient is therefore exposed to an increasingly higher concentration of the drug over the course of therapy. Also, a relatively large amount of drug remains in the nebulizer at the end of therapy. The effect is usually the greatest when medications are nebulized over extended periods.