In clinical studies, metaproterenol started working within five minutes, and the effects of metaproterenol typically lasted for five hours.
When and How to Take Metaproterenol
Following are some general considerations for when and how to take metaproterenol:
Metaproterenol comes in a metered-dose inhaler (called an "MDI").
Some people take metaproterenol only when they need it (during an asthma attack), while others take it regularly to help prevent attacks.
You should "test spray" the metaproterenol inhaler before you use it for the very first time, or if you have not used it for a long period of time. To test spray the inhaler, spray it into the air by pressing on the top of the canister.
Shake your metaproterenol asthma inhaler gently before each use.
Wait at least one minute in between inhalations.
It is important to learn exactly how to use your metaproterenol inhaler. It may be difficult at first and may require some practice.
The spray should be inhaled into the lungs, not sprayed onto the back of the throat and swallowed. To accomplish this, you will need to breathe in while spraying the inhaler.
Most people put the mouthpiece of the inhaler directly into their mouths. However, many healthcare providers now recommend placing the inhaler an inch or two away from the mouth. Talk with your healthcare provider about the best way for you to use the inhaler.
Each inhaler contains 200 sprays (or 100 sprays for a "sample" inhaler). Try to keep track of approximately how many sprays you have used in order to know when to replace the inhaler. Do not place the inhaler in water to see if it is empty (although doing so was recommended in the past).
For metaproterenol to work properly, it must be taken as prescribed. Metaproterenol will not work if you stop taking it.