Brethaire

Care should be taken to ensure that multiple inhalers are utilized in the proper order and that an adequate amount of time is allowed after a B2-agonist and before another product is administered. This will help to maximize penetration and the benefit of the second agent. The same strategy is frequently used with multiple medications delivered via nebulizer, though multiple medications can he delivered simultaneously via nebulizer as an alternative.

Recognizing the environmental problems caused by chlorofluorocarbon propellants used in most MDIs, the Food and Drug Administration has mandated a gradual phase-out of their use to coincide with the development and market approval of CFC MDIs in compliance with the international ban on CFCs. In recent years, therapeutic problems deriving from the old standby MDIs have surfaced to prompt a second look at their design, so the demand for change from CFCs has spurred an evolutionary leap in metered-dose technology. Inhalers suffer from loss of prime; that is, the first actuation after an inhaler has been standing may deliver significantly less than a proper dose, depending on the product itself, the orientation of the canisters while stored and the duration of storage between actuations. They also can deliver inaccurate doses when the active ingredient settles out of solution or suspension and when the canister empties. Of course, the tendency of inhalers to deliver large portions of their doses to the nasophary nx rather than the lungs when used by the average patient without a spacer device of some kind is well documented. Now the CFCs have come under scrutiny concerning their effects on essential rubber components of the actuator valves in inhalers, as they tend to extract polycylic aromatic hydrocarbons, an air pollutant that shares with ozone a large measure of responsibility for exacerbations in asthmatics. It can hardly be efficacious to provide a damaging pollutant along with a dose of medication.

The metered-dose inhalers, seemingly so simple, are very complex, multi-faceted products. The canister contains not only the active ingredient suspended or dissolved in solution, but a surfactant that acts both to maintain the integrity of the suspension and to lubricate the actuator valve, and the propellant. The new hydrofluoroalkane propellants chosen to replace the CFCs have required development of new surfactants, for those used with CFCs are not sufficiently soluble in HFA. The metering valve of actuators, so essential in delivery of consistent and accurate doses, is comprised of seven or eight metal or plastic components manufactured to rigorous tolerances. HFA adversely affects the plastic parts used in these valve mechanisms, so new elastomers had to be developed for their manufacture. New surfactants tended to deliver unsatisfactorily coarse sprays, so the valve mechanisms themselves have had to be redeveloped to counter that problem.

The first entry to the "green" market is Schering's Proventil HFA. Its new propellant (hydrofluoroalkane) keeps the product fully aerosolizable in cold conditions and in any storage position to avoid underdosing and repriming and its MDI mechanism has been redesigned to spray with less force than other albuterol inhalers and to deliver a significantly more accurate and consistent dose. Other albuterol sprays on the market tend to deposit a large portion of each dose forcefully on the back of the pharynx, contributing to the waste and ineffectiveness of these products in the hands of a great many users. The reduced force of the new MDI promises to enhance the effective utilization of each dose by reducing this waste and increasing the amount actually inhaled without the aid of a spacer device.

Conclusions

Asthma has been recognized as a chronic inflammatory disorder that generally requires maintenance anti-inflammatory therapy for optimal outcome. Asthma is increasingly the focus of managed care efforts to maximize pharmaceutical outcomes, where pharmacists and ancillary staff are required to become extensively involved with the asthmatic patient or his caregiver to not only monitor and assess the patient's ongoing condition, but to perpetually educate on proper techniques and procedures. Recent official recommendations for the management of asthma reinforce the regular use of inhalers, which are not only expensive, but difficult to use properly. The pharmacist is in a unique position to help maximize effectiveness of asthma therapy by perpetual patient education.

Program # 401-000-98-006-H01

Goal

In order to provide effective pharmaceutical care, the pharmacist's knowledge of therapeutic options and philosophies in the treatment of asthma must be constantly updated.

Objectives

Upon completion of this program, pharmacists should be able to:

1. Recognize the difference between intermittent and chronic asthma.

2. Discuss treatment options for acute asthma attacks.

3. Discuss treatment options for chronic asthma management.

4. Discuss advantages/disadvantages of medications used in maintenance therapy for chronic asthma.

5. Recommend appropriate therapeutic changes for patients whose asthma is poorly controlled.

6. Discuss the pharmacology of medications used to treat asthma.

To participate in this test, you or your company must have paid for the CE program. If you are not a paid enrollee, please call (813) 627-6735. Enrollees are entitled to 12 free CE lessons worth 2 credit hours (0.2 ceu) each.

Answer the questions at the end of this lesson by completing the answer sheet provided. Completely fill in the circle corresponding to your answer with a black pen (no pencils or blue pens please). A certificate of completion will be sent with a passing grade of 70 percent. Write your 7-digit CE enrollment number on the answer sheet. (See example. It is the last 7 numbers on the second line of your mailing label.)

Affix mailing label and fax to (813) 626-7203 for fastest service, OR mail completed answer sheet to DrSN/CP C.E., P.O. Box 31180, Tampa, Fla. 33631-3180. Lessons expire three years after publication date.

Hypersensitivity reactions

Type I (immediate) IgE response directed at innocuous environmental antigens triggers release of chemical mediators from mast cells, eosinophils and platelets.

Type II (antibody-dependant cytotoxic) IgG binds to either self or foreign antigen to cause phagocytosis, killer cell activation and/or complement fixation and lysis.

Type III: Immune complexes form in quantities sufficient to overwhelm the reticuloendothelial system's ability to clear, leading to serum sickness.

Type IV (delayed): Antigens trapped within macrophages and unable to be cleared cause T-cell stimulation and cytokine [production.sup.6].

Common allergens

Feces and body parts of domestic dust mites

Dander/salivary residue of animals with fur

Feces of cockroaches

Pollens and mold spores

Foods and medications

Airborne chemicals

Other common triggers

Airborne irritants (smoke/fragrances)

Respiratory infection

Physical exercise (especially in cold)

Foods or additives

Weather changes

Aspirin

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COPYRIGHT 2004 Gale Group