No, by-and-large they are not.

Asthma is not an infectious disease. Respiratory infections do make asthma worse or cause an attack of asthma. But these are usually viral infections and as such antibiotics are not required and are not useful. They could kill the good bacteria of the body and cause antibiotic resistance and could be actually harmful.

Let us picturize a usual or common scenario. A patient of asthma gets a sore throat, runny nose, fever and body aches and in a day or two his asthma gets much worse. He goes to his GP and asks the doctor to give some strong medicine because he cannot afford to miss office. The doctor prescribes antibiotics but the patient is no better.

• 90% of the upper respiratory infections are viral.
• 90% of the doctors know this fact.
• 90% of the times the patient ends up getting an antibiotic !!

Resist taking antibiotics for common cold. Unless there is a good reason. And that reason would be:

• Phlegm that is clearly yellow (green phlegm does not indicate bacterial infection in an asthmatic – it is due to eosinophils in the sputum.)
• Fever which had gone down comes back again.
• Throat swab test confirmed bacterial infection.
• Bacterial sinusitis.
• Your doctor clearly feels antibiotics are necessary.

Some patients with severe asthma have a chronic infection of Chlamydia or mycoplasma in the lungs as one of the reasons why their asthma is severe. Such patients may benefit from a prolonged course of certain specific antibiotics.

Asthma is often associated with sinusitis. When there is bacterial infection in the sinuses, as evidenced by pain and tenderness over the sinuses, pain in the upper teeth, dirty or yellow discharge from the nose and radiological evidence of pus in the sinuses, then antibiotics are required. In this situation antibiotics relieve not only the sinus symptoms but also help in better control of asthma.

Other than these few exceptions, antibiotics have no major role in the day to day management of asthma.

The over-use of antibiotics for common childhood asthma is believed to be one of the reasons behind the alarming increase in asthma in children. When we start using antibiotics at the drop of a  hat we do not allow our natural immune system to exert and develop. Our immune system is then misguided and mis-directed and start reacting to harmless substances in the environment. This leads to allergy and asthma.