The form and severity of side effects will vary depending on the type of bronchodilator. High doses of short-acting beta2 agonists, for instance, have been associated with hypokalemia (low potassium levels in the blood, which can result in weakness) and abnormal heart rhythms.

A large clinical study found that the long-acting salmeterol drug was associated with a small, but statistically significant number of deaths in asthma patients. After investigating the drug, the Food and Drug Administration (FDA) updated the safety warnings on all long-acting beta2 agonists (LABA). The labels recommend that LABA medications not be the first medication used to treat asthma and that they should only be used as an additional therapy when a patient’s symptoms fail to respond to other asthma medications, such as low-to-medium dose inhaled corticosteroids.  

Patients concerned about these warnings should NOT stop taking prescribed medication without first consulting their physician. The risk of untreated asthma is much higher than the risk of death from salmeterol.

Regular, frequent use of certain bronchodilators by a person with asthma may even worsen the condition. Patients taking bronchodilators are advised to call their physicians immediately if they experience any of the following symptoms:

• Chest pain
• Severe headache
• Severe vomiting
• Fever or chills
• Fast or pounding heartbeat
• Skin rash
• Hives
• Hoarseness
• Choking or difficulty swallowing
• Loud or high-pitched breathing
• Worsening of symptoms
• Swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs

Less serious side effects should be brought to the attention of a physician and may include:

• Headache
• Anxiety, nervousness, agitation or hyperactivity
• Muscle cramps or tremors
• Coughing
• Dizziness or light-headedness
• Dryness or irritation of mouth or throat
• Unpleasant taste
• Nausea, stomachache or vomiting
• Pinkish-red saliva (isoproterenol only)
• Elevated blood pressure
• Diarrhea
• Difficulty urinating
• Tingling of the hands and feet
• Arching of the back

Patients should discuss all side effects with their physician because certain side effects indicate that the person is receiving too much medication. Physicians may conduct blood tests to determine if the patient is receiving the proper amount.

In addition, certain bronchodilators may cause temporary blurred vision if the medication comes into direct contact with the eyes.