Duoneb

What is it - Duoneb is a combination of albuterol and atrovent in a liquid that is inhaled through an inhaler. It is indicated for patients with COPD. There is a series of contraindications and warnings with this medication:

It is contraindicated in patients with hyersensitivity to soya lecithin or related food products like soybeans or peanuts.

There may be a paradoxical bronchospasm with the use of this medicine. This usually happens first use of a new MDI. Beta adrenergic agents have been reported to produce ECG changes such as flattening of T-Waves, prolonation of QT intervals and ST segment depression

When used with non-potasium sparing diuretics ECG and hypokalemia can worsen.

The albuterol in combivent may cause hypokalemia in some patients.

How does it work - Combivent works by relaxing smooth muscles in bronchial tubes.

In more detail - Albuterol is a relatively selective Beta2-adrenergic bronchodilator. A Beta2-adrenergic refers to recepters associated with smooth muscle cells. These receptors when inhibited cause the muscle to relax and when these the smooth muscles relax the bronchial tubes dialate and the patient breathes easier.

How does it work - The smaller breathing tubes in the lungs are surrounded by smooth muscles. Atrovent antagonizes the action of acetylcholine a substance released by the vagus nerve. The vagus nerve by releasing acetylcholine controls the contractions of those smooth muscles surrounding the breathing tubes.