"Broncodilatadores" are bronchodilators. "Bronchodilatators" do not exist. http://www.fda.gov/cder/foi/label/1997/ritugen112697-lab.pdf
Long-Acting Bronchodilators

Vida media larga is "long half-life". However, they are referred to as long-acting bronchodilators. http://www.asthma.ca/adults/treatment/bronchodilators.php
http://www.asthmatrack.org/meds_bronch_la.html

Sometimes, moderate doses of inhaled steroids alone do not fully control asthma symptoms. You may find that, even though you're taking inhaled steroids regularly, you still experience asthma symptoms, for example, at night or when you exercise.

Long-acting beta-agonists(LABAs) dilate the airway for up to 12 hours and are to be taken along with your inhaled steroids. Currently, researchers do not think that long-acting bronchodilators can reduce inflammation on their own, but they may help the inhaled steroids to work better..

There are several different kinds of long-acting bronchodilators. If you are given the inhaled corticosteroid and LABA in two separate inhalers, make sure you use them both. LABAs are not intended to be used alone for the treatment of asthma. Like any medication, a long-acting bronchodilator should be used only as your doctor advises.



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Note added at 6 hrs (2006-10-29 11:42:13 GMT)
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http://en.wikipedia.org/wiki/Bronchodilator

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Note added at 6 hrs (2006-10-29 11:45:31 GMT)
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So, the correct answer -in my opinion- (also a medical opinion) is long-acting bronchodilators. However, the context of your translation will determine whether to put it that way or to say they are bronchodilators with a long half-life.


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Note added at 6 hrs (2006-10-29 11:47:44 GMT)
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http://www.nottingham.ac.uk/nursing/sonet/rlos/bioproc/halfl...
Pharmacology: Half-life of Drugs

Introduction

The duration of action of a drug is known as its half life. This is the period of time required for the concentration or amount of drug in the body to be reduced by one-half. We usually consider the half life of a drug in relation to the amount of the drug in plasma. A drug’s plasma half-life depends on how quickly the drug is eliminated from the plasma. A drug molecule that leaves plasma may have any of several fates. It can be eliminated from the body, or it can be translocated to another body fluid compartment such as the intracellular fluid or it can be destroyed in the blood. The removal of a drug from the plasma is known as clearance and the distribution of the drug in the various body tissues is known as the volume of distribution. Both of these pharmacokinetic parameters are important in determining the half life of a drug.