Heart risks can be increased by respiratory drugs

Respiratory diseases – such as asthma – are treated by various drugs, including beta-adrenoceptors, antimuscarinics, inhaled and oral corticosteroids, and theophyllines. While most of the drugs have been associated indirectly with cardiac rhythm disorders, epidemiologic proof is limited.

Now, according to a case control study reported in the most recent issue of the journal Epidemiology, there is evidence that irregular heart rhythm most frequently accompanies oral steroid and theophylline use.

Dr. Consuelo Huerta, of Centro Espanol de Investigacion Farmacoepidemiologica in Madrid, and colleagues reviewed respiratory medication use by 710 patients, 10-79 years of age, who experienced an irregular heart rhythm and compared them with 5,000 matched “controls.”

Results identified oral steroids and theophylline as the therapeutic groups associated with risk of developing atrial fibrillation, a risk enhanced with new courses of therapy.

This study’s results are also in line with certain suspected dysrhythmic effects of theophyllines – supraventricular tachycardia associated with antimuscarinics, and ventricular arrhythmias associated with beta-adrenoceptors.

SOURCE: “Respiratory Medications and the Risk of Cardiac Arrhythmias.” Huerta, C; Lanes, SF; Garcia Rodriguez, LA. Epidemiology, 16(3):360-366, May 2005