Thursday, October 11, 2012

What is the difference between a regular and HFA inhaler ?

A propellant is a compressed inert gas that acts as a vehicle for discharging the contents of an aerosol container. They are used in the making of inhalers, more specifically metered dose inhalers (MDI), for the treatment of asthma. For years, chlorofluorocarbon (CFC) was the propellant used to move the albuterol medicine out of the inhaler so the patient can inhale the medication, but because this propellant has been shown to deplete the ozone layer, new asthma inhalers using hydrofluoroalkane (HFA) are now being used. The FDA has ruled that U.S. sales of CFC albuterol inhalers be prohibited after 2008 due to the rising global concerns about CFC's ozone-depleting effects so they have allowed the manufacture of new brands of inhalers that contain HFA and are equally effective at treating asthma symptoms without the negative effects on the ozone layer (see the graph below). Some asthmatics do not approve of the switch because they feel that HFA inhalers release slower and warmer puffs of medicine than the CFC ones, so patients may feel that the new inhalers aren't strong enough to treat asthma symptoms.

Proventil HFA effective CFC equivalent

Graph showing that Proventil HFA is just as effective as the CFC equivalent
(compared to placebo)

source:www.drugs.com

Initially there were three albuterol HFA inhalers that the FDA approved as safe and effective: ProAir HFA, Proventil HFA, and Ventolin HFA (albuterol sulfate) inhalation aerosols. Also available is Xopenex HFA (levalbuterol tartrate) that contains the active form of albuterol with less of the effects of albuterol inhalers because it tends to cause less jitteriness (a common albuterol side effect) in patients than albuterol sulfate inhalers. These inhalers are bronchodilators and are typically used as rescue inhalers to provide asthma relief during an asthma attack.

Albuterol HFA and albuterol CFC inhalers have their differences. They tend to taste and feel different, with the force of the spray being softer for albuterol HFA than for albuterol CFC inhalers. Albuterol HFA inhalers also have to be cleaned and primed to work in the right way and give the right dose of medicine (see diagram below), though actual inhaler use is similar with CFC and HFA inhalers. It is always important for patients to follow the inhaler instructions included with their medication.

regular Inhaler HFA Inhaler defference between reg Inhaler HFA InhalerKeeping HFA inhalers Clean and Working Properly

source:dailymed.nlm.nih.gov

Some HFA inhalers have an inhaler counter which allows the patient to keep track of how much medication they have left and some are alcohol inhalers and contain a small amount of alcohol that can temporarily cause a false reading on breath alcohol tests. There is also a significant difference in the cost of the inhalers. CFC inhalers are usually about $5-$25 each, whereas HFA inhalers can cost $30 to $60, according to the American Academy of Allergy Asthma & Immunology. There are programs available to that provide assistance to patients, allowing them to buy the inhalers at little or no cost.

Source:
www.fda.gov
www.webmd.com