Renal Functions in Bronchial Asthma

Asthma is a lung disease in which the muscles that surround the small airways in your lungs (the bronchi) spasm and constrict, obstructing the passage of air in and out of your lungs. Asthma can usually be controlled by medication such as inhaled corticosteroids or bronchodilators, but some asthma drugs may be contraindicated if you have renal disease.

Causes of Asthma

• According to the Asthma and Allergy Foundation of America, asthma spasms result from a chronic hypersensitivity and inflammation of the bronchi, triggered by certain stimuli. Allergens such as pet dander, pollen, dust, mold and fumes can all cause an asthma attack, as well as an infection, such as bronchitis or viral pneumonia. So can pollution, chemicals, and certain medications and supplements. Cardiac asthma has symptoms like regular asthma, but is triggered by congestive heart failure.

Asthma Medications

• There are two main types of asthma medications, according to the Asthma and Allergy Foundation of America--quick relief and long-term control.

  Quick-relief asthma medications usually include: short-acting inhaled bronchodilators, which open up airways by relaxing muscles; short-acting beta-agonists, which relieve asthma symptoms like wheezing and ease asthma triggered by exercise; and slower-acting bronchodilators, like Theophylline, which act to ease overnight asthma symptoms.

  Long-term control medications include: non-steroids such as Cromolyn Sodium, which is inhaled to prevent airway swelling in asthma attacks; and inhaled corticosteroids such as Flovent and Azmacort, which reduce airway swelling and decrease mucus in the lungs.

Asthma Medications, Potassium Levels and Renal Function

• Slower-acting bronchodilators such as Theophylline may be contraindicated, however, if you have impaired renal function as well as asthma. Using this type of asthma medication can cause increased potassium levels in your body, according to the University of Maryland Medical Center. And while potassium is a mineral that is needed to help the kidneys function normally, too much potassium in the blood (hyperkalemia) can contribute to impaired renal function because your kidneys, when impaired, cannot properly process the potassium out of your body.

Hyperkalemia

• The major causes of hyperkalemia, according to medicinenet.com's website, include renal disease, diseases affecting the adrenal glands and the effects of certain medications such as Theophylline. Symptoms of hyperkalemia can include nausea, fatigue, muscle weakness and tingling sensations, according to the University of Maryland Medical Center, but hyperkalemia can also be asymptomatic, so you may not know that your potassium levels are raised.

  According to the University of Maryland Medical Center, most patients experience a mild form of hyperkalemia, which is treatable and well-tolerated. But any condition, supplement or medication that causes mild hyperkalemia must be treated or stopped to prevent progression into severe hyperkalemia. Extremely high levels of potassium can lead to renal failure, cardiac arrest and death.

Treating Hyperkalemia by Reducing Potassium Levels

• According to the University of Maryland Medical Center, if your doctor diagnoses hyperkalemia, he will recommend you maintain a diet low in potassium, refrain from taking potassium supplements and discontinue or change medications that contribute to higher potassium levels, such as the asthma medication Theophylline. Risk of hyperkalemia is one reason why your doctor should monitor all medications if you have both asthma and impaired renal function, and why you should never take a potassium supplement without a doctor's supervision.