Dictionary.com defines "rescue" in part as "to free from violence or danger." Since an asthma flare-up (attack) is a violent reaction within your air passages that places you in impending danger, it's only fitting that the medicine discovered to end asthma flare-ups be referred to as "rescue medicine."
Asthma is a medical condition where the cells lining the air passages (bronchioles) are chronically inflamed. When exposed to asthma triggers, the inflammation worsens, causing muscles lining these air passages (bronchial muscles) to spasm and contract. These muscles, in essence, squeeze the air passages, making it difficult for air to get out of your lungs, creating a feeling that you can't catch your breath (air hunger, dyspnea, fish out of water).
Since asthma is a reversible disease, it can be reversed either by waiting it out, or by using medicine. For most of history, since most medicine caused only mild relief, most asthmatics were forced to suffer until the symptoms ceased on their own.
So, what exactly does this mean? What is rescue medicine? This means that the medicine, once injected or inhaled, is attracted to and attaches to beta 2 (B2) adrenergic receptors that line the respiratory tract. A chemical reaction then occurs that causes bronchial muscles to relax, causing air passages to open up (dilate), thus ending the asthma flare up.
While this type of medicine is generally referred to as rescue medicine, it is also commonly referred to as bronchodilators, beta 2 adrenergic medicine, or simply B2 agonists.
While epinephrine worked great to make breathing easier, it also worked like a charm as a vasopressor. In other words, while it was a great asthma rescue medicine, this came with many systemic and undesirable side effects, such as increased blood pressure, fast and pounding heart rate, tremors, increasd anxiety and nervousness.
The good news is that, over the years, scientists learned to make synthetic medicine (made in a factory) that mimics the B2 response of epinephrine but avoids the B1 and A1 response. This means that the medicine works better than epinephrine with negligible side effects.
Epinephrine is still available, although it's mainly reserved for emergency situations in hospitals. The most commonly prescribed asthma rescue medicines today include albuterol (Ventolin), which was introduced to the market in 1969, and levalbuterol (Xopenex), which was introduced to the market in 1999.
Albuterol and levalbuterol are available in hospitals and for home use by asthmatics, and are inhaled into the lungs by either using a rescue inhaler or a nebulizer.
Rescue Inhaler: This is an small, easy to use portable device that can easily fit into a pocket and can be taken with you wherever you go. It usually takes just one or two puffs to end an asthma attack. While generally referred to as rescue inhalers, they may also be called "asthma inhalers" or "puffers." Because they are easily portable, inexpensive, and easy to use, they work fine for most asthmatics in most instances. Check out my post "How to use an inhaler."
Nebulizer: This a small cup with a mouthpiece. The medicine for this comes in tiny plastic amps. The amps are opened and the medicine is poured into the nebulizer cup. The nebulizer is then connected to a small air compressor that turns the medicine into a mist to be inhaled using the mouthpiece over 10-20 minutes. These are not as portable as inhalers, although most asthmatics say that they work better during severe asthma attacks. Check out my post "How to properly take a breathing treatment" and "What is a nebulizer?"
Most asthma guidelines recommend that all asthmatics have some form of rescue medicine on hand at all times, whether it be in the form of an inhaler, nebulizer, or both. Providing asthmatics with a prescription for rescue medicine is usually the first thing an asthma physician will do once the diagnosis of asthma is made.
While every asthmatic should have access to rescue medicine, it is no longer considered a top line asthma medicine. This is because emphasis has been changed from treating acute asthma symptoms (flare-ups, asthma attacks) when they occur, to preventing and controlling asthma.
Today, asthma is generally controlled using asthma controller medicines, such as Flovent, Advair, Symbicort, Dulera and Singulair. Studies show that when these medicines are used every day, they help to both control and prevent asthma, thus eliminating (or greatly reducing) the need for rescue medicine.
Yet even people with controlled asthma may still have asthma flare-ups from time to time, and it's for this reason every asthmatics should have both an Asthma Action Plan, and a rescue inhaler or nebulizer available at all times.