What Makes HFA Inhaler Medicine Different From The Inhaler Medicine?

What makes HFA inhaler medicine different from the inhaler medicine I was prescribed a few years ago?

All MDIs contain active asthma medicine along with an inert material called a propellant. The actual medicine in your current HFA inhaler is identical to that found in your older inhaler. The difference lies in an inactive ingredient, the propellant, which as its name indicates, helps to propel the asthma medicine out of the canister.

The major determinant of how deeply and effectively the medication enters the breathing passages is, however, up to you. Correct inhalation technique, not the propellant, is responsible for getting the medicine to where it is most effective! The propellant is a substance called a hydrofluoroalkane, abbreviated HFA. As noted in Question 59, the propellant used in most MDIs until recently was a chlorofluorocarbon (CFC), a substance that has been discovered to play a key role in damaging the protective ozone layer of the atmosphere.

When it comes to inhaled medications, HFA was deemed the best choice to replace CFC. The reformulation of the propellant used in MDIs does not reduce the effectiveness of your inhaled medication. Studies show that albuterol MDIs with HFA are comparable to CFC MDIs; effectiveness and safety profiles are similar.

Interestingly, in the case of the inhaled corticosteroid beclomethasone, the change from CFC to HFA propellant leads to increased amounts of medicine being delivered deeper into the lung, reaching the smallest air passageways, a phenomenon that improves drug delivery and that requires a dose reduction when transitioning from CFC beclomethasone to HFA beclomethasone.

If, for example, you are taking the Ventolin HFA brand of albuterol manufactured by GlaxoSmithKline, you will notice that in addition to the trade name, Ventolin, the label also reads HFA. The active asthma medicine albuterol (a short-acting, quick-relief β2 agonist) in the newer HFA inhaler is identical to the albuterol in the older CFC inhaler; only the propellant is different. The medicine is the same, carries the same name, works just as effectively, and has the added benefit of including a dose counter.

The labeling of newer inhalers is more accurate because it specifies which inert propellant (HFA) is used in your MDI. The change to an HFA inhaler, however, means that you must learn new inhaler facts, as outlined in Table 39. All HFA inhalers require priming prior to first use. That means that you must release a specified number of puffs into the air before you then inhale your first dose from a new MDI or from one that you have not used for some time. Be sure to familiarize yourself with the manufacturer’s instructions (available from your pharmacist or online) so that you know if your inhaler requires three or four priming puffs. Proventil HFA,

Ventolin HFA, and Xopenex HFA require four sprays to prime the inhaler, whereas ProAir requires three sprays. HFA inhalers require repriming sprays if they are not used regularly. Some inhalers may require such a repriming if 2 or more days have elapsed; be certain you know the specifics as they apply to the medicine you have been prescribed! Another fact is that all HFA inhalers have a shelf life; they will need to be discarded after you have released the number of puffs contained in the canister or after a certain amount of time has passed since you first removed the inhaler from its protective overwrap.

Facts About Hydrofluoroalkane (HFA) Containing Inhalers

  • HFA replaced CFC in albuterol containing metered-dose inhalers in the United States as of January 1, 2009.
  • HFA is contained in quick-relief, rapid acting albuterol metered dose inhalers.
  • HFA is contained in some long-acting (LABA) daily-use inhaled β2 bronchodilators.
  • HFA is contained in some daily-use inhaled corticosteroid (ICS) inhalers.
  • HFA, like CFC, is an inert propellant and is not an asthma medicine.
  • HFA containing metered-dose inhalers as compared to CFC containing metered-dose inhalers:
  • Contain the same active asthma medication as CFC inhalers
  • Have different priming instructions/requirements than CFC inhalers
  • Need to be cleaned more frequently than CFC inhalers
  • Create a “softer” spray of medicine than CFC inhalers
  • Do not contribute to depletion of the stratosphere’s ozone layer: “greener

If your HFA MDI has an incorporated dose counter (such as Ventolin HFA), you will know exactly how many doses remain before you will need to refill your prescription. If your inhaler does not have a dose counter, then you must keep track of how many doses you have used up so that you can calculate how many doses remain in the canister. Note that the quick-relief, inhaled, short-acting β2 (SABA) bronchodilators containing albuterol, ProAir, Proventil HFA, Ventolin HFA, or Xopenex HFA all contain 200 doses per canister.

All HFA MDIs are adversely affected by moisture and so are packaged in a protective overwrap after they are manufactured. Once the wrap is opened, the MDI becomes exposed to air and the medicine must be used or discarded within a relatively short period. Each medicine is different; some must be replaced as soon as 60 days after opening, so make certain you find out what applies in the case of the medicine that you have been prescribed.

There is obviously no point inhaling from an MDI if there is no active medicine available to benefit you! HFA inhalers have a gentler, weaker spray and require generation of a slower inhalation compared to the older CFC inhalers; you will not “feel” a spray of HFA in the same manner you did when using a CFC inhaler.

HFA inhalers also create a warmer spray compared to the older CFC inhalers, and you may notice a distinct taste. Because HFA is stickier than CFC, the mouthpiece will require weekly rinsing to prevent clogging the inhaler hole (Table 40). The American College of Chest Physicians advises that “The mouthpiece should be cleaned once weekly by running warm water through the top and bottom for 30 seconds (remove the metal canister first) and then shaking vigorously to remove excess water.

This should be followed by air drying overnight. As with CFC-based inhalers, the metal canisters should never be submerged in water or allowed to get wet.”

Generic HFA inhalers will not become available until current patent protections expire. HFA inhalers sold in the United States thus cost more than their generic CFC predecessors did. GlaxoSmithKline, the manufacturer of Ventolin HFA that contains 200 puffs (doses) per canister makes an HFA inhaler that contains 60 puffs (doses) called ReliOn Ventolin HFA. ReliOn HFA inhalers are distributed exclusively through Walmart stores.

One canister of 60 doses costs less than the standard 200-dose albuterol MDI, so ReliOn Ventolin might be an option if you use albuterol infrequently. In general, if you are experiencing difficulty paying for your prescriptions, you should let your treating doctor know of your circumstances, and you might also con-sider contacting the Partnership for Prescription Assistance: http://www.pparx.org/ or 1-888-4PPA-NOW (1-888-477-2669).