History of Asthma (Part 3): Nebulizers and Inhalers
It's pretty impressive how far asthma medications have come since ancient times. I spoke of many ancient remedies and treatments in part 1 and part 2 of this series and for part 3 I wanted to focus on the timeline of more recent asthma medications and advancements in the last couple of centuries.
Nebulizers & inhalers
The first “powered” nebulizer was invented in France in 1858 by a man named Sales-Girons. He made a device that would atomize medication in liquid form. It was similar to a bicycle pump where you would lift up and push down on a long pump handle which would push the medication through the atomizer and near the persons mouth where they would breathe it in.
In 1864 in Germany, Dr. Siegel invented the first “spray inhaler” which used steam from boiling water underneath the device to force the steam across the medication chamber and draw it out of a glass tube that the patient would then breathe in.
In the early 1900s many asthma patients would use hand held atomizers. In 1910 epinephrine became a first line treatment for asthma flare ups when it became available in a solution that could be nebulized with less side effects than injecting it directly into a vein. The term “aerosol” was first coined in 1920. Also in the early 1900s, asthma cigarettes were widely used by many asthma sufferers as a treatment. These cigarettes contained stramonium as well as various other herbal remedies such as tea leaves, belladonna, and eucalyptus (which later was realized to be a pretty big asthma trigger for many). The directions for inhaling the asthma cigarettes was very similar to both metered dose inhalers (MDI) and dry powder inhalers (DPI) like we have today. Breathe all the way out and then take a deep breath & inhale as much of the smoke in as possible and then hold your breath for several seconds before exhaling.
In the 1930s a gas bulb nebulizer was invented and an asthmatic would inhale an adrenaline chloride in a solution. With the realization that medicine was much more effective when inhaled via mist instead of vapor, the first electric nebulizer called “The Pneumostat” was invented in 1930. This particular nebulizer was so expensive that most patients couldn't afford it and would still opt to use a hand powered nebulizer.
The first pressurized metered dose inhaler (pMDI) hit the market in 1955 by Dr. George Maison, who got the idea from his teenage daughter after seeing perfume spray devices. In 1956 new medications were formulated and approved for this inhaler: Medihaler-Epi (epinephrine) and Medihaler-Iso (isoproterenol). In the 1960s there was a pretty serious epidemic of asthma deaths and these medications were superseded by more selective short acting beta-agonist albuterol and the first inhaled corticosteroid (ICS) beclomethasone. Since that time, MDI’s have made leaps and bounds to what we have today. Jet and ultrasonic nebulizers were improved and devices that were breath-actuated, breath-enhanced. Vibrating mesh nebulizers were more recently released on the market and are very handy, efficient little devices.
The first MDIs were made with CFC (chlorofluorocarbon) propellant systems and were found to be detrimental to the environment, specifically to the ozone layer. A replacement propellant was developed and CFCs were replaced with HFA (Hydrofluoroalkane). The substitution of HFA propellants changed the make up of the inhalers and in turn made a softer spray that wasn't as cold as the CFC inhalers. All CFC inhalers were phased out by the FDA in 2008. The phasing out of CFCs paved the way for an increase in development of dry powder inhalers (DPI) which before this time weren't as widely used. In more recent years, the Respimat type of inhaler was developed which is propellant free and the medication comes out in a mist which can penetrate deeper into the lungs. Also, the first breath actuated albuterol rescue inhaler (DPI) also hit the market in 2015.
While I've only covered a fraction of the history of asthma medications in this post, it's pretty easy to see how far asthma treatment has come over just the past 150 years.
Can you even imagine how much further asthma treatment will come in the next 150 years?
Have you ever gotten "moon face" as a side effect of prednisone?