Respiratory Diseases

Antihistamines are used to block the body's production of histamines that cause allergy symptoms. Cold medicines usually contain antihistamines, decongestants, and non-narcotic analgesics like aspirin. Though the antihistamines are not effective against the cold viruses, they do cause drowsiness, and that may help to alleviate the sleeplessness that often accompanies a cold. The analgesics help against the fever and headaches that accompany a cold, while the decongestant temporarily relieves a stuffy nose.

While decongestants can be taken orally, the two most effective ways of taking decongestants are nose drops and nasal sprays. Caution should be taken to prevent what is known as the rebound congestion effect. The decongestant medicine is applied right to the site of the swollen tissues, where it relieves the congestion in minutes by constricting the blood vessels. When decongestants are discontinued after prolonged use, the body may fail to marshal its own constrictive response. The congestion can then become worse than before the medicine was taken. Therefore, it is advisable to use decongestants for only a short period of time.